2022 |
|
Indications for a bound tetraneutron T. Faestermann, A. Bergmaier, R. Gernhäuser, D. Koll and M. Mahgoub; Physics Letters B 824 (2022) 136799. |
| Abstract: Using the reaction 7Li(7Li,10C) we tried to populate states in the tetraneutron. A peak in the energy spectrum of identified 10C, which we cannot attribute to a reaction with any other of the target components, corresponds to an excitation of the 10C+4n system of 2.93±0.16 MeV. Under different kinematic conditions an equivalent peak was observed. For a binding energy of the tetraneutron of −2.93 MeV a much larger width than the observed upper limit of Γ<0.24 MeV (mainly due to experimental spread) is expected. Therefore, we favor the interpretation that this peak corresponds to 10C in the first excited state at 3.354 MeV and a tetraneutron with a binding energy of +0.42±0.16 MeV. |
BibTeX:
@article{Faestermann2022,
author = {Faestermann, Thomas and Bergmaier, Andreas and Gernhäuser, Roman and Koll, Dominik and Mahgoub, Mahmoud},
title = {Indications for a bound tetraneutron},
journal = {Physics Letters B},
type = {OpenAccess},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2022},
volume = {824},
pages = {136799},
url = {https://www.sciencedirect.com/science/article/pii/S0370269321007395},
doi = {https://doi.org/10.1016/j.physletb.2021.136799}
}
|
2020 |
|
Ion beam analysis of fusion plasma-facing materials and components: facilities and research challenges M. Mayer, S. Möller, M. Rubel, A. Widdowson, S. Charisopoulos, T. Ahlgren, E. Alves, G. Apostolopoulos, N.P. Barradas, S. Donnelly, S. Fazinić, K. Heinola, O. Kakuee, H. Khodja, A. Kimura, A. Lagoyannis, M. Li, S. Markelj, M. Mudrinic, P. Petersson, I. Portnykh, D. Primetzhofer, P. Reichart, D. Ridikas, T. Silva, S.M.G. de Vicente and Y.Q. Wang; Nuclear Fusion 60 (2) (2020) 025001. |
| Abstract: Following the IAEA Technical Meeting on ‘Advanced Methodologies for the Analysis of Materials in Energy Applications Using Ion Beam Accelerators’, this paper reviews the current status of ion beam analysis (IBA) techniques and some aspects of ion-induced radiation damage in materials for the field of materials relevant to fusion. Available facilities, apparatus development, future research options and challenges are presented and discussed. The analysis of beryllium and radioactivity-containing samples from future experiments in JET or ITER represents not only an analytical but also a technical challenge. A comprehensive list of the facilities, their current status, and analytical capabilities comes alongside detailed descriptions of the labs. A discussion of future issues of sample handling and the current status of facilities at JET complete the technical section. To prepare the international IBA community for these challenges, the IAEA technical meeting concludes the necessity for determining new nuclear reaction cross-sections and improving the inter-laboratory comparability by defining international standards and testing these via a round-robin test. |
BibTeX:
@article{Mayer2020,
author = {Mayer, M. and Möller, S. and Rubel, M. and Widdowson, A. and Charisopoulos, S. and Ahlgren, T. and Alves, E. and Apostolopoulos, G. and Barradas, N. P. and Donnelly, S. and Fazinić, S. and Heinola, K. and Kakuee, O. and Khodja, H. and Kimura, A. and Lagoyannis, A. and Li, M. and Markelj, S. and Mudrinic, M. and Petersson, P. and Portnykh, I. and Primetzhofer, D. and Reichart, P. and Ridikas, D. and Silva, T. and de Vicente, S. M. Gonzalez and Wang, Y. Q.},
title = {Ion beam analysis of fusion plasma-facing materials and components: facilities and research challenges},
journal = {Nuclear Fusion},
publisher = {IOP Publishing},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2020},
volume = {60},
number = {2},
pages = {025001},
url = {https://iopscience.iop.org/article/10.1088/1741-4326/ab58177},
doi = {https://doi.org/10.1088/1741-4326/ab5817}
}
|
|
Sputtering of LiF and other halide crystals in the electronic energy loss regime M. Toulemonde, W. Assmann, B. Ban-d’Etat, M. Bender, A. Bergmaier, P. Boduch, S. Della Negra, J. Duan, A.S. El-Said, F.F. Grüner, J. Liu, D. Lelièvre, H. Rothard, T. Seidl, D. Severin, J.P. Stoquert, K.-O. Voss and C. Trautmann; The European Physical Journal D 74 (2020) 144. |
| Abstract: Sputtering experiments were performed by irradiating LiF, NaCl, and RbCl crystals with various swift heavy ions like S, Ni, I, Au with energies between 60 and 210 MeV, C60 clusters between 12 and 30 MeV or Pb ions between 730 and 6040 MeV. Sputtered species are collected on arc-shaped catchers and subsequently analyzed by elastic recoil detection analysis or Rutherford backscattering analysis. The study focuses on angular distributions and total yields for LiF and covers a broad range of experimental parameters including cleaved or rough sample surfaces, ion fluence, beam incident angles, and different ion velocities leading to electronic energy loss (Se) values from 5 to 45 keV/nm. In most cases, the angular distribution has two components, a jet-like peak perpendicular to the surface sample superimposed on a broad isotropic cosine distribution whatever is the beam incident angle. The observation of the jet depends mainly on the surface flatness and angle of ion incidence. However, the jet does not appear clearly when irradiated with C60 cluster. The sputtering yield is stoichiometric and characterized by huge total yields of up to a few 105 atoms per incident ion. The yield follows a power law as function of electronic energy loss, Y follows an exponential law with Sen with n 4. While the azimuthal symmetry for sputtering is observed at low ion velocity ( 1 MeV/u), it seems to be lost at high velocity (>4 MeV/u). The data provide a comprehensive overview how the angular distribution and the total sputtering yield scale with the energy loss, beam incidence angle and ion velocity. Complementary experiments have been done with NaCl and RbCl targets confirming the observation made for LiF. |
BibTeX:
@article{Toulemonde2020,
author = {Toulemonde, Marcel and Assmann, Walter and Ban-d’Etat, Brigitte and Bender, Markus and Bergmaier, Andreas and Boduch, Philippe and Della Negra, Serge and Duan, Jinglai and El-Said, Aymann S. and Grüner, Florian Florian and Liu, Jie and Lelièvre, Daniel and Rothard, Hermann and Seidl, Tim and Severin, Daniel and Stoquert, Jean Paul and Voss, Kay-Obe and Trautmann, Christina},
title = {Sputtering of LiF and other halide crystals in the electronic energy loss regime},
journal = {The European Physical Journal D},
type = {OpenAccess},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2020},
volume = {74},
pages = {144},
url = {https://link.springer.com/article/10.1140/epjd/e2020-10040-9},
doi = {https://doi.org/10.1140/epjd/e2020-10040-9}
}
|
2019 |
|
Growth and characterization of β-Ga2O3 thin films on different substrates S.J. Hao, M. Hetzl, F. Schuster, K. Danielewicz, A. Bergmaier, G. Dollinger, Q.L. Sai, C.T. Xia, T. Hoffmann, M. Wiesinger, S. Matich, W. Aigner and M. Stutzmann; Journal of Applied Physics 125 (10) (2019) 105701. |
| Abstract: β-Ga2O3 thin films were grown on the substrates of sapphire, GaN, and single crystals of β-Ga2O3, using plasma-assisted molecular beam epitaxy. By varying deposition conditions, pure-phase epitaxial β-Ga2O3 thin films were obtained, and the crystal quality of the as-grown films was optimized. A systematic characterization and a detailed analysis were performed on the films, including the nucleation process, surface morphology, crystal quality, thermal stability, as well as electrical and optical properties. Optical absorption was investigated using photothermal deflection spectroscopy, which provides detailed information about sub-gap optical absorption. Photocurrent measurements indicated a pronounced persistent photo-conductivity of β-Ga2O3. A blue-UV emission with an energy of 3-3.5 eV was observed by cathodoluminescence spectroscopy. The Fermi level position of the as-grown film was determined based on temperature-dependent electrical conductivity measurements. It is proposed that oxygen vacancies in the film form a defect band at around E c-0.8 eV that pins the Fermi level and is related to the observed photocurrent and cathodoluminescence characteristics. |
BibTeX:
@article{Hao2019,
author = {Hao, S. J. and Hetzl, M. and Schuster, F. and Danielewicz, K. and Bergmaier, A. and Dollinger, G. and Sai, Q. L. and Xia, C. T. and Hoffmann, T. and Wiesinger, M. and Matich, S. and Aigner, W. and Stutzmann, M.},
title = {Growth and characterization of β-Ga2O3 thin films on different substrates},
journal = {Journal of Applied Physics},
publisher = {American Institute of Physics},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2019},
volume = {125},
number = {10},
pages = {105701},
url = {https://aip.scitation.org/doi/10.1063/1.5061794},
doi = {https://doi.org/10.1063/1.5061794}
}
|
|
Full Elemental Depth-profiling with Nanoscale Resolution: The Potential of Elastic Recoil Detection (ERD) in Membrane Science R. Verbeke, A. Bergmaier, S. Eschbaumer, H. Mariën, G. Dollinger and I.F.J. Vankelecom; Journal of Membrane Science 572 (2019) 102-109. |
| Abstract: Extensive characterization is needed to understand how the physicochemical properties of polymeric membranes are related to their transport properties and to allow optimization of membrane design. Currently, most techniques characterize the (near)-surface region of the membrane, even though its bulk obviously also plays a significant role in the final membrane performance. To achieve depth-profiles of the elemental composition of both integrally skinned asymmetric (ISA) and thin-film composite (TFC) membranes, elastic recoil detection (ERD), an ion beam analysis technique, is now introduced to the field as a potentially highly valuable tool to complement for instance XPS, EDX or RBS. The determination of the complete elemental composition, importantly also including hydrogen, as function of the membrane thickness allows to gain knowledge about its depth-heterogeneity at an impressive combination of ca. 15 nm resolution with ppm-range sensitivity. This very low detection limit additionally allows the analytical quantification of e.g. remnants from synthesis conditions. The potential as well as the pitfalls of ERD as a novel, valuable technique for membrane characterization are critically discussed and illustrated by the determination of the thickness of polyamide-based top-layers of TFC membranes. |
BibTeX:
@article{Verbeke2019,
author = {Verbeke, R. and Bergmaier, A. and Eschbaumer, S. and Mariën, H. and Dollinger, G. and Vankelecom, I. F. J.},
title = {Full Elemental Depth-profiling with Nanoscale Resolution: The Potential of Elastic Recoil Detection (ERD) in Membrane Science},
journal = {Journal of Membrane Science},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2019},
volume = {572},
pages = {102-109},
note = {cited By 0},
url = {https://www.sciencedirect.com/science/article/pii/S0376738818322476?via%3Dihub},
doi = {https://doi.org/10.1016/j.memsci.2018.10.045}
}
|
|
Elemental Depth Profiling of Chlorinated Polyamide-Based Thin-Film Composite Membranes with Elastic Recoil Detection R. Verbeke, A. Bergmaier, S. Eschbaumer, V. Gómez, G. Dollinger and I. Vankelecom; Environ. Sci. Technol. 53 (15) (2019) 8640-8648. |
| Abstract: The chlorine resistance of nanofiltration and reverse osmosis membranes is of high importance in the water treatment industry. Elastic recoil detection (ERD) is now presented as a powerful tool to uniquely provide elemental depth profiles, including hydrogen, of NaOCl-treated polyamide-based thin-film composite (TFC) membranes. The influence of pressure, pH, and chlorine feed concentration on the volume-averaged Cl uptake, the location of chlorine throughout the membrane, and the z-gradient in the Cl/N ratio is demonstrated. The results suggest that (i) higher volume-averaged Cl uptakes are achieved at higher chlorine doses and at acidic pH; (ii) chlorination is mostly restricted to the top layer; (iii) a gradient in the Cl/N ratio exists along the membrane depth; and (iv) the shape of this gradient is influenced by the chlorination pH and the applied pressure. Conclusions on the chlorination mechanisms could also be deduced. Conversely, no conclusive relationships between H fractions and Cl uptake could be drawn, even though changes in the H content after chlorination were observed. To corroborate these results and fully exploit the potential of ERD, the exact microstructure of the (chlorinated) TFC membranes should be better understood. The chlorine resistance of nanofiltration and reverse osmosis membranes is of high importance in the water treatment industry. Elastic recoil detection (ERD) is now presented as a powerful tool to uniquely provide elemental depth profiles, including hydrogen, of NaOCl-treated polyamide-based thin-film composite (TFC) membranes. The influence of pressure, pH, and chlorine feed concentration on the volume-averaged Cl uptake, the location of chlorine throughout the membrane, and the z-gradient in the Cl/N ratio is demonstrated. The results suggest that (i) higher volume-averaged Cl uptakes are achieved at higher chlorine doses and at acidic pH; (ii) chlorination is mostly restricted to the top layer; (iii) a gradient in the Cl/N ratio exists along the membrane depth; and (iv) the shape of this gradient is influenced by the chlorination pH and the applied pressure. Conclusions on the chlorination mechanisms could also be deduced. Conversely, no conclusive relationships between H fractions and Cl uptake could be drawn, even though changes in the H content after chlorination were observed. To corroborate these results and fully exploit the potential of ERD, the exact microstructure of the (chlorinated) TFC membranes should be better understood. |
BibTeX:
@article{Verbeke2019a,
author = {Verbeke, Rhea and Bergmaier, Andreas and Eschbaumer, Stephan and Gómez, Verónica and Dollinger, Günther and Vankelecom, Ivo},
title = {Elemental Depth Profiling of Chlorinated Polyamide-Based Thin-Film Composite Membranes with Elastic Recoil Detection},
journal = {Environ. Sci. Technol.},
publisher = {American Chemical Society},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2019},
volume = {53},
number = {15},
pages = {8640--8648},
url = {https://pubs.acs.org/doi/10.1021/acs.est.8b07226},
doi = {https://doi.org/10.1021/acs.est.8b07226}
}
|
2018 |
|
Physics at the Munich Tandem Accelerator Laboratory G. Dollinger and T. Faestermann; Nuclear Physics News 28 (1) (2018) 5-12. |
| Abstract: The Tandem accelerator situated in Garching, just 20 km north of Munich, is of the “Emperor” (MP) series manufactured by High Voltage Engineering Corporation (HVEC). It delivered the first beams for experiments in 1970 and came close to its design voltage of 10 MV. In 1991 the tubes were exchanged to the extended version of HVEC. Routine operation at a terminal voltage of 14 MV was then possible. |
BibTeX:
@article{Dollinger2018,
author = {Günther Dollinger and Thomas Faestermann},
title = {Physics at the Munich Tandem Accelerator Laboratory},
journal = {Nuclear Physics News},
publisher = {Taylor & Francis},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2018},
volume = {28},
number = {1},
pages = {5-12},
url = {https://www.tandfonline.com/doi/full/10.1080/10619127.2018.1427405},
doi = {https://doi.org/10.1080/10619127.2018.1427405}
}
|
|
Physics at the Munich Tandem Accelerator Laboratory G. Dollinger and T. Faestermann; ArXiv (v2) (2018) . |
| Abstract: This review reports on the science performed in various fields at the Munich tandem accelerator during the past decade. It covers nuclear structure studies, also with respect to astro- and particle physics as well as for the understanding of fundamental symmetries, the extremely sensitive detection of long-lived radionuclides from Supernova or r-process production with accelerator mass spectrometry and studies of the elemental composition of thin films with extreme depth resolution and sensitivity by elastic recoil detection (ERD). The ion microbeam is used for 3D hydrogen microscopy as well as in radiobiology to study the response of living cells on well-defined irradiations. In medical research new therapeutic methods of tumour irradiation are tested using proton minibeams as well as the determination of ion ranges in tissue with iono-acoustics. Primary and secondary beams from the accelerator are also used for development and testing of detector components in large setups, e.g. at the LHC, and for testing new kinds of fuel materials of high uranium density to use them as medium enriched fuels at the Munich research reactor FRM II in the future. |
BibTeX:
@openaccess{Dollinger2018a,
author = {Günther Dollinger and Thomas Faestermann},
title = {Physics at the Munich Tandem Accelerator Laboratory},
journal = {ArXiv},
type = {OpenAccess},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2018},
number = {v2},
url = {https://arxiv.org/abs/1802.07057}
}
|
|
Building a multi-cathode gas-filled detector M. Mahgoub, G. Souadi, A. Bergmaier, M. Böhmer, T. Faestermann and R. Gernhäuser; AIP Conference Proceedings 1976 (2018) 020011. |
| Abstract: Detecting and identifying the nuclear radiation or decay yield with high accuracy is still an experimental challenge and has to be optimized for each application. One of the most commonly used instrument is the proportional counter, which measures the energy of incident particles, by producing ionization output proportional to the particle energy. This ionization output allows the discrimination of particles with same charge e.g. positron, protons, alpha or heavier ions. Another widely used instrument is the scintillator detector, which measures the energy of incident particle, also by producing light in the scintillator material, that is collected and multiplied in the output pulse of a photo-multiplier tube PMT. The Multi-Cathode Gas-filled Scintillator MCGS detector we are building gets advantages of the proportional chambers and the scintillator detectors. It identifies the particles by measuring their energy loss Eloss in the proportional chamber due to the collision with the atoms of the filling gas, and the rest energy Erest of the particles which is measured when the particles are stopped in the scintillator material. A high rate data acquisition system is under development to be used by the detector. © 2018 Author(s). |
BibTeX:
@article{Mahgoub2018,
author = {Mahgoub, M. and Souadi, G.O. and Bergmaier, A. and Böhmer, M. and Faestermann, T. and Gernhäuser, R.},
title = {Building a multi-cathode gas-filled detector},
journal = {AIP Conference Proceedings},
type = {OpenAccess},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2018},
volume = {1976},
pages = {020011},
note = {cited By 0},
url = {https://aip.scitation.org/doi/abs/10.1063/1.5042378},
doi = {https://doi.org/10.1063/1.5042378}
}
|
2017 |
|
Time of flight assisted ΔE-E method for enhanced isotope separation capabilities in heavy ion elastic recoil detection analysis S. Eschbaumer, A. Bergmaier, D. Seiler and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 406 (2017) 10 - 14. |
| Abstract: The time of flight energy (TOF-E) setup installed at the scattering chamber of the Q3D magnetic spectrograph to perform heavy ion elastic recoil detection (ERD) analysis at the 14 MV Munich Tandem Accelerator has recently been upgraded. Now, the energy detector of the TOF-E setup is additionally capable of performing ΔE-E measurements for high energy recoil ions obtained from e.g. a 170 MeV 127I projectile beam. Time of flight information is simultaneously acquired with the ΔE-E data for each detected ion. The combination of the TOF-E and the ΔE-E data gives the opportunity to set effective filter conditions to select for both, the elemental and the mass of the detected ion. As an example a boron doped carbon layer is analyzed and 10B and 11B is separated with the help of the combination of both methods. |
BibTeX:
@article{Eschbaumer2017,
author = {S. Eschbaumer and A. Bergmaier and D. Seiler and G. Dollinger},
title = {Time of flight assisted ΔE-E method for enhanced isotope separation capabilities in heavy ion elastic recoil detection analysis},
journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2017},
volume = {406},
pages = {10 - 14},
note = {Proceedings of the 12th European Conference on Accelerators in Applied Research and Technology (ECAART12)},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X17301751},
doi = {https://doi.org/10.1016/j.nimb.2017.02.056}
}
|
|
A position sensitive time of flight setup forheavy ion elastic recoil detection analysis Stephan Eschbaumer; Dissertation, Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther, 2017. |
| Abstract: The measurement of elemental concentrations as a function of depth is vital for the understanding of the physical properties and thereby quality of thin, functional layers produced and utilized in e.g. microelectronics and in the semiconductor technology. In this work, a position sensitive time of flight setup (TOF-E) for the quantitative analysis by high energetic (EP ≈ 0.2 MeV⋅A) heavy ion elastic recoil detection (ERD) was developed and installed at the scattering chamber of the Q3D magnetic spectrograph located at the Munich Tandem Accelerator. The spectrometer is utilized for the quantifcation of the high resolution, single element depth profiles obtained with the Q3D magnetic spectrograph and as stand alone ERD detection system for the simultaneous analysis of all elements from 1 ≤ M ≤ 178 with high depth resolution. A high energy- and thereby depth resolution can only be achieved by the correction of kinematic effects of the scattering process. Thus, the first timing detector, as well as the ionization chamber based energy detector were designed to additionally offer a position sensitivity. Using an electrostatic lens which images the secondary electrons created by the recoil ions on penetration of a thin carbon foil in forward emission direction, a position resolution of 0.6 mm (FWHM) was achieved by the first time detector. In combination with a position resolution of the energy detector of 2.4 mm (FWHM), which is acquired by a drift time measurement of the ionization electrons within the gas volume, the true scattering angle of each recoil ion can be determined with an angular resolution of 2.5 mrad (FWHM). This allows to reduce the contributions of the kinematic effects on the energy resolution from 3.3% to 0.4%. By the detection of secondary electrons in backward emission direction within the first timing detector and within a second timing detector, an overall time resolution of 280 ps (FWHM) was achieved. In standard ERD measurements this allows, utilizing a 40 MeV 197Au projectile beam at an incident angle of 4° to achieve a surface energy resolution from the time of flight information of 0.76% and thereby a depth resolution of 2.3 nm (FWHM). Furthermore, the setup allows elemental separation up to a mass of 40 with a mass resolution of ΔM < 1. At high projectile energies (EP ≈ 1.3 MeV⋅A), the setup also offers the ability to perform ERD analysis utilizing a TOF-ΔE-ERes technique. The benefit of this technique is given by combining the inherent mass sensitivity of the TOF-E method with the sensitivity of the ΔE-ERes method to the nuclear charge. Both together allow to create unique filter conditions for background suppression and an overall sensitivity enhancement. This was demonstrated for the diffcult case of the detection of low nitrogen amounts within diamond. A sensitivity of 10 ppm was achieved with this technique, which is better by two orders of magnitude compared to conventional ΔE-ERes analysis. In addition to that, the method also allows for isotope separation in a medium heavy mass range of 12 ≤ M leg 40, which is not possible with the ΔE-ERes method. |
BibTeX:
@phdthesis{Eschbaumer2017diss,
author = {Stephan Eschbaumer},
title = {A position sensitive time of flight setup forheavy ion elastic recoil detection analysis},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2017},
url = {https://athene-forschung.rz.unibw-muenchen.de/node?id=121342}
}
|
2016 |
|
A position sensitive time of flight detector for heavy ion ERD S. Eschbaumer, A. Bergmaier and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms 371 (2016) 125-131. |
| Abstract: Abstract A new 2D position sensitive time of flight detector for heavy ion ERD has been developed. The detector features separate time and position measurement in a straight geometry. An electrostatic lens focuses the secondary electrons ejected from a carbon foil onto a channel plate stack maintaining the position information despite the electron momentum distribution. For position readout a 2D Backgammon anode is used. A position resolution of <0.6 mm (FWHM) and a time resolution of 96 ps (FWHM) is demonstrated. |
BibTeX:
@article{Eschbaumer2016,
author = {Eschbaumer, S. and Bergmaier, A. and Dollinger, G.},
title = {A position sensitive time of flight detector for heavy ion ERD},
booktitle = {The 22nd International Conference on Ion Beam Analysis (IBA 2015)},
journal = {Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2016},
volume = {371},
pages = {125--131},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X15008952},
doi = {https://doi.org/10.1016/j.nimb.2015.09.036}
}
|
|
Material selection for hybrid floating gate NAND memory applications J.G. Lisoni, L. Breuil, P. Blomme, J. Meersschaut, A. Bergmaier, G. Dollinger, G. Van den Bosch and J. Van Houdt; physica status solidi (a) 213 (2) (2016) 237-244. |
| Abstract: This article discusses the materials aspects involved in the successful integration of hybrid floating gate (HFG) devices for NAND applications. In HFG, a Si(n type)p type) stack replaces the standard poly-Si FG. The high work function metal helps to enlarge the program window by limiting the leakage through the high-k intergate dielectric (IGD); the use of high-k IGD enables to scale the equivalent oxide thickness (EOT) of the HFG cell. Our recent progresses in the understanding of the materials characteristics (IGD crystallinity and HFG-IGD thermal stability) that influence memory performance have allowed to demonstrate that HFG can be a solution to scale planar flash beyond the 20 nm node with the best preferable hybrid floating gate structure being a Ru-based HFG and a 3-layers IGD stack of HfAlO\Al2O3\HfAlO. Indeed, through the correct selection and combination of materials for process conditions that are relevant in flash memory fabrication flows, we will show that program windows can be suitably engineered. Finally, the materials challenges for keeping acceptable memory retention characteristics are also highlighted. |
BibTeX:
@article{Lisoni2016,
author = {Lisoni, Judit G. and Breuil, Laurent and Blomme, Pieter and Meersschaut, Johan and Bergmaier, Andreas and Dollinger, Günther and Van den Bosch, Geert and Van Houdt, Jan},
title = {Material selection for hybrid floating gate NAND memory applications},
journal = {physica status solidi (a)},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2016},
volume = {213},
number = {2},
pages = {237--244},
url = {http://onlinelibrary.wiley.com/doi/10.1002/pssa.201532829/abstract},
doi = {https://doi.org/10.1002/pssa.201532829}
}
|
2015 |
|
Determination of molecular stopping cross section of 12C, 16O, 28Si, 35Cl, 58Ni, 79Br, and 127I in silicon nitride N. Barradas, A. Bergmaier, K. Mizohata, M. Msimanga, J. Räisänen, T. Sajavaara and A. Simon; Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms 360 (2015) 90-96. |
| Abstract: Silicon nitride is a technologically important material in a range of applications due to a combination of important properties. Ion beam analysis techniques, and in particular, heavy ion elastic recoil detection analysis can be used to determine the stoichiometry of silicon nitride films, which often deviates from the ideal Si |
BibTeX:
@article{Barradas2015,
author = {Barradas, N.P. and Bergmaier, A. and Mizohata, K. and Msimanga, M. and Räisänen, J. and Sajavaara, T. and Simon, A.},
title = {Determination of molecular stopping cross section of 12C, 16O, 28Si, 35Cl, 58Ni, 79Br, and 127I in silicon nitride},
journal = {Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2015},
volume = {360},
pages = {90-96},
note = {cited By 2},
url = {https://www.sciencedirect.com/science/article/pii/S0168583X15007697?via%3Dihub},
doi = {https://doi.org/10.1016/j.nimb.2015.08.034}
}
|
2014 |
|
New experimental molecular stopping cross section data of Al 2O3, for heavy ions A. Simon, N. Pessoa Barradas, A. Bergmaier, M. Msimanga, I. Bogdanovic Radovic, J. Räisänen and T. Sajavaara; Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms 332 (2014) 341-345. |
| Abstract: Molecular stopping cross section data of Al2O3, for heavy ions of 12C, 16O, 28Si, 35Cl, 79Br within the energy range of 0.01-1.0 MeV/nucleon were measured. Both direct transmission and bulk analysis methods were applied. Stopping cross sections were calculated both with the SRIM and MSTAR codes. Evaluation and intercomparison of the new data with the calculated and previously measured ones are reported in this paper. |
BibTeX:
@article{Simon2014,
author = {Simon, A. and Pessoa Barradas, N. and Bergmaier, A. and Msimanga, M. and Bogdanovic Radovic, I. and Räisänen, J. and Sajavaara, T.},
title = {New experimental molecular stopping cross section data of Al 2O3, for heavy ions},
journal = {Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2014},
volume = {332},
pages = {341-345},
note = {cited By 5},
url = {https://www.sciencedirect.com/science/article/pii/S0168583X14003498?via%3Dihub},
doi = {https://doi.org/10.1016/j.nimb.2014.02.092}
}
|
2013 |
|
Accurate determination of optical bandgap and lattice parameters of Zn 1-xMgxO epitaxial films (0 ≤ x ≤ 0.3) grown by plasma-assisted molecular beam epitaxy on a-plane sapphire B. Laumer, F. Schuster, M. Stutzmann, A. Bergmaier, G. Dollinger and M. Eickhoff; Journal of Applied Physics 113 (23) (2013) 233512. |
| Abstract: Zn1-xMgxO epitaxial films with Mg concentrations 0 ≤ x ≤ 0.3 were grown by plasma-assisted molecular beam epitaxy on a-plane sapphire substrates. Precise determination of the Mg concentration x was performed by elastic recoil detection analysis. The bandgap energy was extracted from absorption measurements with high accuracy taking electron-hole interaction and exciton-phonon complexes into account. From these results a linear relationship between bandgap energy and Mg concentration is established for x ≤ 0.3. Due to alloy disorder, the increase of the photoluminescence emission energy with Mg concentration is less pronounced. An analysis of the lattice parameters reveals that the epitaxial films grow biaxially strained on a-plane sapphire. |
BibTeX:
@article{Laumer2013,
author = {Laumer, B. and Schuster, F. and Stutzmann, M. and Bergmaier, A. and Dollinger, G. and Eickhoff, M.},
title = {Accurate determination of optical bandgap and lattice parameters of Zn 1-xMgxO epitaxial films (0 ≤ x ≤ 0.3) grown by plasma-assisted molecular beam epitaxy on a-plane sapphire},
journal = {Journal of Applied Physics},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2013},
volume = {113},
number = {23},
pages = {233512},
note = {cited By (since 1996)1},
url = {http://scitation.aip.org/content/aip/journal/jap/113/23/10.1063/1.4811693},
doi = {https://doi.org/10.1063/1.4811693}
}
|
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Transport behaviour of boron delta-doped diamond J. Scharpf, A. Denisenko, C. Pakes, S. Rubanov, A. Bergmaier, G. Dollinger, C. Pietzka and E. Kohn; Physica Status Solidi (A) Applications and Materials Science 210 (10) (2013) 2028-2034. |
| Abstract: The electrical transport properties of two-dimensional (2D) boron-doped delta layers were investigated by a comprehensive analysis of physical, electrochemical and microscopic methods. The boron concentration profile was determined physically by elastic recoil detection (ERD) and compared to the doping (acceptor) profile extracted from capacitance-voltage (CV) measurements, giving a boron concentration of 2-4 × 1013 cm-2. Corresponding field effect transistor (FET) characteristics, based on the boron-doped delta channel concept, measured in electrolyte, show good modulation behaviour but field effect mobilities in the range of 10-2-10 -1 cm2 V-1 s-1 that are far below expected values. High-resolution transmission electron microscopy (HR-TEM) analysis was employed to shed new light on the transport behaviour of boron-doped delta layers, revealing an inhomogeneous and interrupted morphology. Based on this finding, a hypothesis is proposed, modelling the delta layer transport behaviour via hopping and tunnelling processes between boron clusters. |
BibTeX:
@article{Scharpf2013,
author = {Scharpf, J. and Denisenko, A. and Pakes, C.I. and Rubanov, S. and Bergmaier, A. and Dollinger, G. and Pietzka, C. and Kohn, E.},
title = {Transport behaviour of boron delta-doped diamond},
journal = {Physica Status Solidi (A) Applications and Materials Science},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2013},
volume = {210},
number = {10},
pages = {2028-2034},
note = {cited By (since 1996)0},
url = {http://onlinelibrary.wiley.com/doi/10.1002/pssa.201300093/abstract},
doi = {https://doi.org/10.1002/pssa.201300093}
}
|
|
Absolute partial decay branching-ratios in 16O C. Wheldon, N. Ashwood, M. Barr, N. Curtis, M. Freer, T. Kokalova, J. Malcolm, S. Spencer, V. Ziman, T. Faestermann, R. Krücken, H.-F. Wirth, R. Hertenberger, R. Lutter and A. Bergmaier; Journal of Physics: Conference Series 436 (1) (2013) 012017. |
| Abstract: The α-transfer reaction 6 12C(3 6Li, d)8 16O* has been performed at a 6Li bombarding energy of 42 MeV to populate excited states in 13C and 16O. Absolute branching ratios have been unambiguously determined for states in the excitation energy range 13.85 to 15.87 MeV and reduced widths are extracted. |
BibTeX:
@article{Wheldon2013,
author = {Wheldon, C. and Ashwood, N.I. and Barr, M. and Curtis, N. and Freer, M. and Kokalova, Tz. and Malcolm, J.D. and Spencer, S.J. and Ziman, V.A. and Faestermann, Th. and Krücken, R. and Wirth, H.-F. and Hertenberger, R. and Lutter, R. and Bergmaier, A.},
title = {Absolute partial decay branching-ratios in 16O},
journal = {Journal of Physics: Conference Series},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2013},
volume = {436},
number = {1},
pages = {012017},
note = {cited By 1},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/436/1/012017/meta},
doi = {https://doi.org/10.1088/1742-6596/436/1/012017}
}
|
2012 |
|
Thin layer composition profiling with angular resolved x-ray photoemission spectroscopy: Factors affecting quantitative results T. Conard, W. Vandervorst, A. Bergmaier and K. Kimura; Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films 30 (3) (2012) 031509. |
| Abstract: Composition profiling of thin films in the nanometer range is critical to the development of future electronic devices. However, the number of techniques with such depth resolution is limited. Among them, angle-resolved x-ray photoelectron spectroscopy (ARXPS) can be used for thin layers up to a few nanometers, but it is not yet a fully established method. In order to evaluate its capabilities for use as a routine and general method, the authors evaluate both its intrinsic capabilities in comparison with other methods and the factors affecting quantification by analyzing its variability when applied at various laboratory locations with different tools and data treatments. For this purpose, dedicated samples based on multilayers of HfO 2 and SiON were produced with a well-determined layer structure. The results show that ARXPS, including depth profiling reconstruction, is very efficient and compares favorably with nuclear analysis techniques. It allows the separation of the surface contamination signal from the interfacial layer signal and allows determination of the coverage quantitatively. An accuracy of ±10 is achieved for most elements except for nitrogen, where strong peak interference with hafnium and a low intensity increase the inaccuracy up to 20. This study also highlights several technique limitations. First, the quality of the retrieved profile is strongly dependent upon the exact determination of each photoemission peak intensity. Also it demonstrates that, while favorable for chemical identification, very high resolution spectra may lead to larger errors in profile reconstruction due to larger statistical errors in the intensities, though this is true mainly for deeper layers. Finally, it points out the importance of the physical parameters used in the final obtained results. |
BibTeX:
@article{Conard2012,
author = {Conard, T. and Vandervorst, W. and Bergmaier, A. and Kimura, K.},
title = {Thin layer composition profiling with angular resolved x-ray photoemission spectroscopy: Factors affecting quantitative results},
journal = {Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2012},
volume = {30},
number = {3},
pages = {031509},
note = {cited By 9},
url = {https://avs.scitation.org/doi/10.1116/1.4704603},
doi = {https://doi.org/10.1116/1.4704603}
}
|
|
Growth sector dependence and mechanism of stress formation in epitaxial diamond growth M. Fischer, S. Gsell, M. Schreck and A. Bergmaier; Applied Physics Letters 100 (4) (2012) 041906. |
| Abstract: Stress generation in epitaxial diamond growth was investigated by μ-Raman spectroscopy and high resolution x-ray diffraction. Intrinsic stress could be varied systematically from compressive to tensile covering a huge range of 5 GPa. The temperature-stress curve for growth on 111-sectors as compared to 001 shows a shift of -200 °C or +2 GPa. A crucial role of hydrogen in the stress formation process is excluded. Due to the absence of grain boundaries, a model is proposed which is based on the "effective climb" of individual dislocations. The controlled generation of stress profiles offers a powerful concept for strengthening diamond mechanical devices. |
BibTeX:
@article{Fischer2012,
author = {Fischer, M. and Gsell, S. and Schreck, M. and Bergmaier, A.},
title = {Growth sector dependence and mechanism of stress formation in epitaxial diamond growth},
journal = {Applied Physics Letters},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2012},
volume = {100},
number = {4},
pages = {041906},
note = {cited By 13},
url = {https://aip.scitation.org/doi/10.1063/1.3679611},
doi = {https://doi.org/10.1063/1.3679611}
}
|
|
Growth study of nonpolar Zn 1-xMg xO epitaxial films on a-plane bulk ZnO by plasma-assisted molecular beam epitaxy B. Laumer, F. Schuster, M. Stutzmann, A. Bergmaier, G. Dollinger, S. Vogel, K. Gries, K. Volz and M. Eickhoff; Applied Physics Letters 101 (12) (2012) 122106. |
| Abstract: Nonpolar Zn 1-x Mg x O epitaxial films were grown by plasma-assisted molecular beam epitaxy on a-plane ZnO substrates. A smooth surface morphology was accomplished under oxygen-rich growth conditions. The benefits of the use of ZnO substrates on the structural properties are reflected by a low-density of threading dislocations. Furthermore, no indications for the generation of basal plane stacking faults are found. The pseudomorphic growth on a-plane ZnO substrates efficiently locks the epitaxial Zn 1-x Mg x O films to the wurtzite structure up to x = 0.25. The Mg concentration is not constant and increases with larger thickness. The optical properties reflect the influence of alloy disorder. |
BibTeX:
@article{Laumer2012,
author = {Laumer, B. and Schuster, F. and Stutzmann, M. and Bergmaier, A. and Dollinger, G. and Vogel, S. and Gries, K.I. and Volz, K. and Eickhoff, M.},
title = {Growth study of nonpolar Zn 1-xMg xO epitaxial films on a-plane bulk ZnO by plasma-assisted molecular beam epitaxy},
journal = {Applied Physics Letters},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2012},
volume = {101},
number = {12},
pages = {122106},
note = {cited By (since 1996)1},
url = {https://aip.scitation.org/doi/10.1063/1.4754076},
doi = {https://doi.org/10.1063/1.4754076}
}
|
|
Absolute decay width measurements in 16O C. Wheldon, N. Ashwood, M. Barr, N. Curtis, M. Freer, T. Kokalova, J. Malcolm, S. Spencer, V. Ziman, T. Faestermann, R. Krücken, H.-F. Wirth, R. Hertenberger, R. Lutter and A. Bergmaier; Journal of Physics: Conference Series 381 (1) (2012) 012078. |
| Abstract: The reaction 126C(63Li, d) 168O* at a 6Li bombarding energy of 42 MeV has been used to populate excited states in 16O. The deuteron ejectiles were measured using the high-resolution Munich Q3D spectrograph. A large-acceptance silicon-strip detector array was used to register the recoil and break-up products. This complete kinematic set-up has enabled absolute α-decay widths to be measured with high-resolution in the 13.9 to 15.9 MeV excitation energy regime in 16O; many for the first time. This energy region spans the 14.4 MeV four-α breakup threshold. Monte-Carlo simulations of the detector geometry and break-up processes yield detection efficiencies for the two dominant decay modes of 40% and 37% for the α+12C(g.s.) and a+12C(2+1) break-up channels respectively. |
BibTeX:
@article{Wheldon2012,
author = {Wheldon, C. and Ashwood, N.I. and Barr, M. and Curtis, N. and Freer, M. and Kokalova, Tz. and Malcolm, J.D. and Spencer, S.J. and Ziman, V.A. and Faestermann, Th. and Krücken, R. and Wirth, H.-F. and Hertenberger, R. and Lutter, R. and Bergmaier, A.},
title = {Absolute decay width measurements in 16O},
journal = {Journal of Physics: Conference Series},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2012},
volume = {381},
number = {1},
pages = {012078},
note = {cited By 0},
url = {https://iopscience.iop.org/article/10.1088/1742-6596/381/1/012078/meta},
doi = {https://doi.org/10.1088/1742-6596/381/1/012078}
}
|
2011 |
|
Comprehensive comparison of various techniques for the analysis of elemental distributions in thin films D. Abou-Ras, R. Caballero, C.-H. Fischer, C. Kaufmann, I. Lauermann, R. Mainz, H. Mönig, A. Schöpke, C. Stephan, C. Streeck, S. Schorr, A. Eicke, M. Döbeli, B. Gade, J. Hinrichs, T. Nunney, H. Dijkstra, V. Hoffmann, D. Klemm, V. Efimova, A. Bergmaier, G. Dollinger, T. Wirth, W. Unger, A. Rockett, A. Perez-Rodriguez, J. Alvarez-Garcia, V. Izquierdo-Roca, T. Schmid, P.-P. Choi, M. Müller, F. Bertram, J. Christen, H. Khatri, R. Collins, S. Marsillac and I. Kötschau; Microscopy and Microanalysis 17 (5) (2011) 728-751. |
| Abstract: The present work shows results on elemental distribution analyses in Cu(In,Ga)Se2 thin films for solar cells performed by use of wavelength-dispersive and energy-dispersive X-ray spectrometry (EDX) in a scanning electron microscope, EDX in a transmission electron microscope, X-ray photoelectron, angle-dependent soft X-ray emission, secondary ion-mass (SIMS), time-of-flight SIMS, sputtered neutral mass, glow-discharge optical emission and glow-discharge mass, Auger electron, and Rutherford backscattering spectrometry, by use of scanning Auger electron microscopy, Raman depth profiling, and Raman mapping, as well as by use of elastic recoil detection analysis, grazing-incidence X-ray and electron backscatter diffraction, and grazing-incidence X-ray fluorescence analysis. The Cu(In,Ga)Se2 thin films used for the present comparison were produced during the same identical deposition run and exhibit thicknesses of about 2 μm. The analysis techniques were compared with respect to their spatial and depth resolutions, measuring speeds, availabilities, and detection limits. |
BibTeX:
@article{Abou-Ras2011,
author = {Abou-Ras, D. and Caballero, R. and Fischer, C.-H. and Kaufmann, C.A. and Lauermann, I. and Mainz, R. and Mönig, H. and Schöpke, A. and Stephan, C. and Streeck, C. and Schorr, S. and Eicke, A. and Döbeli, M. and Gade, B. and Hinrichs, J. and Nunney, T. and Dijkstra, H. and Hoffmann, V. and Klemm, D. and Efimova, V. and Bergmaier, A. and Dollinger, G. and Wirth, T. and Unger, W. and Rockett, A.A. and Perez-Rodriguez, A. and Alvarez-Garcia, J. and Izquierdo-Roca, V. and Schmid, T. and Choi, P.-P. and Müller, M. and Bertram, F. and Christen, J. and Khatri, H. and Collins, R.W. and Marsillac, S. and Kötschau, I.},
title = {Comprehensive comparison of various techniques for the analysis of elemental distributions in thin films},
journal = {Microscopy and Microanalysis},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2011},
volume = {17},
number = {5},
pages = {728--751},
note = {cited By (since 1996)16},
url = {http://journals.cambridge.org/action/displayAbstract?fromPage=online&aid=8386415&fileId=S1431927611000523},
doi = {https://doi.org/10.1017/S1431927611000523}
}
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High-resolution measurement of absolute α-decay widths in O16 C. Wheldon, N. Ashwood, M. Barr, N. Curtis, M. Freer, T. Kokalova, J. Malcolm, S. Spencer, V. Ziman, T. Faestermann, R. Krücken, H.-F. Wirth, R. Hertenberger, R. Lutter and A. Bergmaier; Physical Review C - Nuclear Physics 83 (6) (2011) 064324. |
| Abstract: By using a large-acceptance position-sensitive silicon detector array in coincidence with the high-resolution Munich Q3D spectrograph, unambiguous measurements have been made of the absolute α-particle decay widths from excited states in O16* in the energy range 13.85 to 15.87 MeV. Carbon targets have been bombarded with 42-MeV Li6 beams to induce 612C(36Li, d)816O* reactions. The deuteron ejectiles were measured in the Q3D and the results gated by He4+C12 breakup products detected in the silicon array, the efficiency of which was modeled using Monte Carlo simulations. By comparing total population and breakup-gated spectra, the following absolute α-decay widths have been measured with high resolution: Γα0/ Γtot =0.87±0.11 (13.980 MeV), 1.04±0.15 (14.302 MeV), 0.92±0.10 (14.399 MeV), 0.59±0.04 (14.815 MeV), 0.88±0.18 (15.785 MeV), and Γα1/Γ tot=1.14±0.08 (14.660 MeV), 0.46±0.06 (14.815 MeV). |
BibTeX:
@article{Wheldon2011,
author = {Wheldon, C. and Ashwood, N.I. and Barr, M. and Curtis, N. and Freer, M. and Kokalova, T. and Malcolm, J.D. and Spencer, S.J. and Ziman, V.A. and Faestermann, T. and Krücken, R. and Wirth, H.-F. and Hertenberger, R. and Lutter, R. and Bergmaier, A.},
title = {High-resolution measurement of absolute α-decay widths in O16},
journal = {Physical Review C - Nuclear Physics},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2011},
volume = {83},
number = {6},
pages = {064324},
note = {cited By 21},
url = {https://journals.aps.org/prc/abstract/10.1103/PhysRevC.83.064324},
doi = {https://doi.org/10.1103/PhysRevC.83.064324}
}
|
2010 |
|
Precise nitrogen depth profiling by high-resolution RBS in combination with angle-resolved XPS K. Kimura, K. Nakajima, T. Conard, W. Vandervorst, A. Bergmaier and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B 268 (11-12) (2010) 1960-1963. |
| Abstract: Nitrogen depth profiling in a high-k gate stack structure, SiON/HfO2/SiON/Si(0 0 1) was performed by high-resolution Rutherford backscattering spectroscopy (HRBS) in combination with angle-resolved X-ray photoelectron spectroscopy (AR-XPS). The nitrogen depth profile is determined so that both the HRBS spectrum and the angular dependence of the XPS yield are reproduced. The obtained nitrogen profile is compared with the result of high-resolution elastic recoil detection (ERD) which is the most reliable technique for depth profiling of light elements. The agreement between the result of the present combination analysis and that of high-resolution ERD is fairly good, showing that the present combination analysis is a promising method for the analysis of light elements. |
BibTeX:
@article{Kimura2010,
author = {Kimura, K. and Nakajima, K. and Conard, T. and Vandervorst, W. and Bergmaier, A. and Dollinger, G.},
title = {Precise nitrogen depth profiling by high-resolution RBS in combination with angle-resolved XPS},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2010},
volume = {268},
number = {11-12},
pages = {1960-1963},
note = {cited By (since 1996)2},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X1000203X},
doi = {https://doi.org/10.1016/j.nimb.2010.02.108}
}
|
|
Analysis of ultra-Thin HfO2/SiON/Si(001): Comparison of three different techniques K. Kimura, K. Nakajima, T. Conard, W. Vandervorst, A. Bergmaier and G. Dollinger; Analytical Sciences 26 (2) (2010) 223-226. |
| Abstract: Composition depth profiling of HfO2 (2.5 nm)/SiON (1.6 nm)/Si(001) was performed by three diffetent analytical techniques: high-resolution Rutherford backscattering spectroscopy (HRBS), angle-resolved X-ray photoelectron spectroscopy (AR-XPS) and high-resolution elastic recoil detection (HR-ERD). By comparing these results we found the following: (1) HRBS generally provides accurate depth profiles. However, care must be taken in backgroud subtraction for depth profiling of light elements. (2) In the standard AR-XPS analysis, a simple exponential formula is often used to calculate the photoelectron escape probability. This simple formula, however, cannot be used for the precise depth profiling. (2) Although HR-ERD is the most reliable technique for the depth profiling of light elements, it may suffer from multiple scattering, which deteriorates the depth resolution, and also may cause a large background. |
BibTeX:
@article{Kimura2010a,
author = {Kimura, K. and Nakajima, K. and Conard, T. and Vandervorst, W. and Bergmaier, A. and Dollinger, G.},
title = {Analysis of ultra-Thin HfO2/SiON/Si(001): Comparison of three different techniques},
journal = {Analytical Sciences},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2010},
volume = {26},
number = {2},
pages = {223--226},
note = {cited By (since 1996)2},
url = {https://www.jstage.jst.go.jp/article/analsci/26/2/26_2_223/_article},
doi = {https://doi.org/10.2116/analsci.26.223}
}
|
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A new value for the half-life of 10Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting G. Korschinek, A. Bergmaier, T. Faestermann, U. Gerstmann, K. Knie, G. Rugel, A. Wallner, I. Dillmann, G. Dollinger, C. von Gostomski, K. Kossert, M. Maiti, M. Poutivtsev and A. Remmert; Nuclear Instruments and Methods in Physics Research Section B 268 (2) (2010) 187-191. |
| Abstract: The importance of 10Be in different applications of accelerator mass spectrometry (AMS) is well-known. In this context the half-life of 10Be has a crucial impact, and an accurate and precise determination of the half-life is a prerequisite for many of the applications of 10Be in cosmic-ray and earth science research. Recently, the value of the 10Be half-life has been the centre of much debate. In order to overcome uncertainties inherent in previous determinations, we introduced a new method of high accuracy and precision. An aliquot of our highly enriched 10Be master solution was serially diluted with increasing well-known masses of 9Be. We then determined the initial 10Be concentration by least square fit to the series of measurements of the resultant 10Be/9Be ratio. In order to minimize uncertainties because of mass bias which plague other low-energy mass spectrometric methods, we used for the first time Heavy-Ion Elastic Recoil Detection (HI-ERD) for the determination of the 10Be/9Be isotopic ratios, a technique which does not suffer from difficult to control mass fractionation. The specific activity of the master solution was measured by means of accurate liquid scintillation counting (LSC). The resultant combination of the 10Be concentration and activity yields a 10Be half-life of T1/2 = 1.388 ± 0.018 (1 s, 1.30%) Ma. In a parallel but independent study (Chmeleff et al. [11]), found a value of 1.386 ± 0.016 (1.15%) Ma. Our recommended weighted mean and mean standard error for the new value for 10Be half-life based on these two independent measurements is 1.387 ± 0.012 (0.87%) Ma. |
BibTeX:
@article{Korschinek2010,
author = {Korschinek, G. and Bergmaier, A. and Faestermann, T. and Gerstmann, U.C. and Knie, K. and Rugel, G. and Wallner, A. and Dillmann, I. and Dollinger, G. and von Gostomski, Ch.L. and Kossert, K. and Maiti, M. and Poutivtsev, M. and Remmert, A.},
title = {A new value for the half-life of 10Be by Heavy-Ion Elastic Recoil Detection and liquid scintillation counting},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2010},
volume = {268},
number = {2},
pages = {187--191},
note = {cited By (since 1996)163},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X09009872},
doi = {https://doi.org/10.1016/j.nimb.2009.09.020}
}
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Bimodal range distributions of low-energy carbon ions in tetrahedral amorphous carbon P. Neumaier, A. Bergmaier, W. Eckstein, R. Fischer, H. Hofsäss, H. Jäger, H. Kröger, C. Ronning and G. Dollinger; EPL 90 (4) (2010) 46002. |
| Abstract: Range and mixing distributions of carbon ions deposited onto tetrahedral amorphous carbon films at kinetic energies between 22 eV and 692 eV are measured utilizing high-resolution elastic recoil detection. These data are compared to respective calculations based on binary collision approximation as well as to classical molecular-dynamics simulations. The measured range profiles reveal asymmetric, bimodal structures which are not reproduced from theories. The measured mixing distributions approve the measured range distributions, in particular the observed differences between theory and experiment, which have to be considered in subplantation growth models. |
BibTeX:
@article{Neumaier2010,
author = {Neumaier, P. and Bergmaier, A. and Eckstein, W. and Fischer, R. and Hofsäss, H. and Jäger, H.U. and Kröger, H. and Ronning, C. and Dollinger, G.},
title = {Bimodal range distributions of low-energy carbon ions in tetrahedral amorphous carbon},
journal = {EPL},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2010},
volume = {90},
number = {4},
pages = {46002},
note = {cited By (since 1996)0},
url = {http://iopscience.iop.org/article/10.1209/0295-5075/90/46002/meta},
doi = {https://doi.org/10.1209/0295-5075/90/46002}
}
|
2009 |
|
Swift heavy ion irradiation induced effects in Si/SiOx multi-layered films and nanostructures J. Gerlach, C. Patzig, W. Assmann, A. Bergmaier, T. Höche, J. Zajadacz, R. Fechner and B. Rauschenbach; Materials Research Society Symposium Proceedings 1181 (2009) 1181-DD04-01. |
| Abstract: Amorphous Si/SiOx multilayered films and nanostructures were deposited on Si substrates by the glancing angle deposition technique using Ar ion beam sputtering of a Si sputter target in an intermittent oxygen atmosphere at room temperature. The chemical composition of the samples was characterized by time-of-flight secondary ion mass spectrometry, as well as - for quantifying these first results - by elastic recoil detection analysis using a 200 MeV Au ion beam. The latter method was found to lead to a significant alteration of the sample morphology, resulting in the formation of complex nanometric structures within the layer stacks. In order to investigate these swift heavy ion irradiation induced effects in more detail, a series of experiments was performed to determine the dominating influences. For this purpose, specific glancing angle deposited multi-layered films and nanostructures were irradiated to constant ion fluence with the same 200 MeV Au ion beam at different incidence angles. Scanning electron microscopy of the stacks before and after swift Au ion irradiation revealed considerable changes in film morphology and density as a function of the ion incidence angle, such as an increased porosity of the silicon layers, accompanied by layer swelling. In contrast, the SiOx layers did not show such effects, but exhibited clearly visible swift heavy ion tracks. The observed effects became stronger with decreasing ion incidence angle. |
BibTeX:
@article{Gerlach2009,
author = {Gerlach, J.W. and Patzig, C. and Assmann, W. and Bergmaier, A. and Höche, T. and Zajadacz, J. and Fechner, R. and Rauschenbach, B.},
title = {Swift heavy ion irradiation induced effects in Si/SiOx multi-layered films and nanostructures},
booktitle = {Materials Research Society Symposium Proceedings},
journal = {Materials Research Society Symposium Proceedings},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2009},
volume = {1181},
pages = {1181-DD04-01},
note = {cited By 0},
url = {https://www.cambridge.org/core/journals/mrs-online-proceedings-library-archive/article/swift-heavy-ion-irradiation-induced-effects-in-sisiox-multilayered-films-and-nanostructures/D5C6F79367CC60ED56D9E7F62B9E79FB},
doi = {https://doi.org/10.1557/PROC-1181-DD04-01}
}
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Role of cross-shell excitations in the reaction 54Fe(d →, p)55Fe M. Mahgoub, R. Krücken, T. Faestermann, A. Bergmaier, D. Bucurescu, R. Hertenberger, T. Kröll, H.-F. Wirth and A. Lisetskiy; European Physical Journal A 40 (1) (2009) 35-43. |
| Abstract: The reaction 54Fe(d→, p)55Fe was studied at the Munich Q3D spectrograph with a 14MeV polarized deuteron beam. Excitation energies, angular distributions and analyzing powers were measured for 39 states up to 4.5MeV excitation energy. Spin and parity assignments were made and spectroscopic factors deduced by comparison to DWBA calculations. The results were compared to predictions by large-scale shell model calculations in the full pf -shell and it was found that reasonable agreement for energies and spectroscopic factors below 2.5MeV could only be obtained if up to 6 particles were allowed to be excited from the f 7/2 orbital into p 3/2 , f 5/2 , and p 1/2 orbitals across the N = 28 gap. For levels above 2.5MeV the experimental strength distribution was found to be significantly more fragmented than predicted by the shell model calculations. |
BibTeX:
@article{Mahgoub2009,
author = {Mahgoub, M. and Krücken, R. and Faestermann, Th. and Bergmaier, A. and Bucurescu, D. and Hertenberger, R. and Kröll, Th. and Wirth, H.-F. and Lisetskiy, A.F.},
title = {Role of cross-shell excitations in the reaction 54Fe(d →, p)55Fe},
journal = {European Physical Journal A},
type = {OpenAccess},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2009},
volume = {40},
number = {1},
pages = {35-43},
note = {cited By 3},
url = {https://link.springer.com/article/10.1140%2Fepja%2Fi2008-10727-x},
doi = {https://doi.org/10.1140/epja/i2008-10727-x}
}
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A Time of Flight-Energy spectrometer for stopping power measurements in Heavy Ion-ERD analysis at iThemba LABS M. Msimanga, C. Comrie, C. Pineda-Vargas, S. Murray, R. Bark and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B 267 (16) (2009) 2671-2674. |
| Abstract: The quantitative analysis of thin layers using Heavy Ion-Elastic Recoil Detection (HI-ERD) can be reliably performed if the stopping powers of the probing ions and recoils in a given target matrix are known accurately. Unfortunately for many projectile/target combinations experimental data is limited and where available, deviations of up to 50% between experiment and theory have been reported. This presentation describes the assembly of a Time of Flight-Energy (ToF-E) detector system developed for HI-ERD analysis and adapted for stopping power measurements at iThemba LABS. First results from energy loss measurements of 0.1-0.5 MeV/nucleon 28Si and 84Kr ions in ZrO2 are presented and compared with predictions of the widely used SRIM2003 (Stopping Range of Ions in Matter). |
BibTeX:
@article{Msimanga2009,
author = {Msimanga, M. and Comrie, C.M. and Pineda-Vargas, C.A. and Murray, S. and Bark, R. and Dollinger, G.},
title = {A Time of Flight-Energy spectrometer for stopping power measurements in Heavy Ion-ERD analysis at iThemba LABS},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2009},
volume = {267},
number = {16},
pages = {2671-2674},
note = {cited By (since 1996)4},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X09006235},
doi = {https://doi.org/10.1016/j.nimb.2009.05.014}
}
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Correlation of chemical composition and electrical properties of rf sputtered alumina films M. Voigt, A. Bergmaier, G. Dollinger and M. Sokolowski; Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films 27 (2) (2009) 234-244. |
| Abstract: Alumina films were prepared by radio frequency magnetron sputtering from an aluminum oxide target on an indium tin oxide covered glass. The purpose of the study was to test the influence of the sputter parameters on the elemental composition, surface morphology, and electrical insulation properties (breakdown fields and leakage currents). Tested parameters were the sputter gas (Ar) pressure, the sputter rate, the sputter power, the sputter gas composition (Ar: O2), the conditioning of the target, the residual base pressure, and the substrate temperature. The surface morphology of the films was investigated by atomic force microscopy. Depth profiles of the elemental compositions were measured by elastic recoil detection using energetic heavy ions, and the insulation properties were investigated by current voltage measurements and impedance spectroscopy. The main finding is that the leakage currents increase by about five orders of magnitude, if the atomic ratio of O:Al increases from 1.35 to 2.0. In parallel the breakdown fields decrease by a factor of 100, and the character of the breakdowns changes from soft to hard. The highest breakdown fields (2.4 MVcm) and smallest leakage currents (6.5× 10-8 A cm2 at 2.0 MVcm) are obtained for slightly Al rich films with small atomic concentrations of H (<0.5 at. %). These films were sputtered in pure Ar and under the lowest possible pressure of the residual gas. |
BibTeX:
@article{Voigt2009,
author = {Voigt, M. and Bergmaier, A. and Dollinger, G. and Sokolowski, M.},
title = {Correlation of chemical composition and electrical properties of rf sputtered alumina films},
journal = {Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2009},
volume = {27},
number = {2},
pages = {234--244},
note = {cited By (since 1996)8},
url = {http://avs.scitation.org/doi/10.1116/1.3065978},
doi = {https://doi.org/10.1116/1.3065978}
}
|
2008 |
|
Surface characterization of diamond-like carbon for ultracold neutron storage F. Atchison, A. Bergmaier, M. Daum, M. Döbeli, G. Dollinger, P. Fierlinger, A. Foelske, R. Henneck, S. Heule, M. Kasprzak, K. Kirch, A. Knecht, M. Kuźniak, A. Pichlmaier, R. Schelldorfer and G. Zsigmond; Nuclear Instruments and Methods in Physics Research Section A 587 (1) (2008) 82-88. |
| Abstract: We report the characterization of diamond-like carbon (DLC) surfaces to be used for the storage of ultracold neutrons (UCN). The samples investigated were 100-300-nm-thick tetragonal amorphous carbon (ta-C) coatings produced by vacuum-arc technology on thin foils (0.1-0.2 mm aluminum, stainless steel, PET). The diamond sp3 fraction was determined by X-ray photoelectron spectroscopy (XPS) to be in the range 45-65%. Secondary-ion mass spectroscopy (SIMS) and elastic recoil detection analysis (ERDA) yielded consistent results for the hydrogen contribution (about 1×1016 cm-2 within the top 20 nm), strongly concentrated within a surface layer of 1 nm thickness. The boron contamination was found to be around 50 at. ppm. The fractional hole area of the coatings is on a level of about 1×10-4. Temperature cycling of mechanically pre-stressed samples between 77 and 380 K revealed no detrimental effect. |
BibTeX:
@article{Atchison2008,
author = {Atchison, F. and Bergmaier, A. and Daum, M. and Döbeli, M. and Dollinger, G. and Fierlinger, P. and Foelske, A. and Henneck, R. and Heule, S. and Kasprzak, M. and Kirch, K. and Knecht, A. and Kuźniak, M. and Pichlmaier, A. and Schelldorfer, R. and Zsigmond, G.},
title = {Surface characterization of diamond-like carbon for ultracold neutron storage},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2008},
volume = {587},
number = {1},
pages = {82--88},
note = {cited By (since 1996)5},
url = {http://www.sciencedirect.com/science/article/pii/S0168900207025004},
doi = {https://doi.org/10.1016/j.nima.2007.12.037}
}
|
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Characteristics of boron δ-doped diamond for electronic applications H. El-Hajj, A. Denisenko, A. Bergmaier, G. Dollinger, M. Kubovic and E. Kohn; Diamond and Related Materials 17 (4-5) (2008) 409-414. |
| Abstract: Boron delta-doped profiles with peak concentrations above the full activation limit have been grown on (100)-oriented single crystal diamond substrates by microwave assisted CVD using a solid doping source technique. The growth process was optimized targeting electronic device applications. Up to now these profiles could only be analyzed by chemical/physical profiling and it had been difficult to relate these profiles to the electrical characteristics. For the first time, ERD (Electron Recoil Detection) profiles could be correlated with free carrier profiles extracted by electrochemical profiling based on electrochemical impedance analysis. The comparison shows, that it is possible to incorporate boron on acceptor site with high efficiency even for concentrations in the order of 1021 cm- 3 by the doping technique developed. |
BibTeX:
@article{El-Hajj2008,
author = {El-Hajj, H. and Denisenko, A. and Bergmaier, A. and Dollinger, G. and Kubovic, M. and Kohn, E.},
title = {Characteristics of boron δ-doped diamond for electronic applications},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2008},
volume = {17},
number = {4-5},
pages = {409--414},
note = {cited By (since 1996)16},
url = {http://www.sciencedirect.com/science/article/pii/S092596350700502X},
doi = {https://doi.org/10.1016/j.diamond.2007.12.030}
}
|
2007 |
|
Doping density depth profiling analysis with high resolution elastic recoil detection A. Bergmaier and G. Dollinger; ECS Transactions 11 (3) (2007) 243-255. |
| Abstract: The quantitative analysis of light elements in ultra thin films thinner than 10 nm is still a nontrivial task. This paper summarizes the prospects of high-resolution Elastic Recoil Detection (ERD) using a Q3D magnetic spectrograph. It is shown that sub-nanometer resolution can be achieved in ultra thin films and even monolayer resolution is possible close to the surface. ERD has the best quantification possibilities compared to any other method. Sensitivity is sufficient to analyze main elements and impurities as e,g, necessary for the characterization of microelectronic materials, In addition, high-resolution channeling ERD can be performed in order to obtain information on lattice location of light elements in crystalline ultra thin layers. The potential of high-resolution ERD is demonstrated by several applications where it is the most valuable tool for elemental profiling. |
BibTeX:
@article{Bergmaier2007,
author = {Bergmaier, A. and Dollinger, G.},
title = {Doping density depth profiling analysis with high resolution elastic recoil detection},
booktitle = {212th ECS Meeting},
journal = {ECS Transactions},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2007},
volume = {11},
number = {3},
pages = {243--255},
url = {http://ecst.ecsdl.org/content/11/3/243},
doi = {https://doi.org/10.1149/1.2778668}
}
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Development of isobar separation for 182Hf AMS measurements of astrophysical interest C. Vockenhuber, A. Bergmaier, T. Faestermann, K. Knie, G. Korschinek, W. Kutschera, G. Rugel, P. Steier, K. Vorderwinkler and A. Wallner; Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms 259 (1) (2007) 250-255. |
| Abstract: The detection of 182Hf by Accelerator Mass Spectrometry (AMS) is greatly complicated because of the stable and common isobar 182W. Although significant W reduction can be achieved during negative ion formation using HfF5 -, additional separation is necessary to achieve detection sensitivities sufficient for astrophysical applications, i.e. detection of potential supernova-produced 182Hf on Earth. In this paper, we present a new development of isobar separation using the ΔTOF detection method at the Munich MP Tandem accelerator (TV = 14 MV), where ion energies for 182Hf of about 1 MeV/amu can be achieved. Particular attention is drawn on specific energy loss and energy loss straggling measurements in various materials, the basis for our method of isobar separation. © 2007 Elsevier B.V. All rights reserved. |
BibTeX:
@article{Vockenhuber2007,
author = {Vockenhuber, C. and Bergmaier, A. and Faestermann, T. and Knie, K. and Korschinek, G. and Kutschera, W. and Rugel, G. and Steier, P. and Vorderwinkler, K. and Wallner, A.},
title = {Development of isobar separation for 182Hf AMS measurements of astrophysical interest},
journal = {Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2007},
volume = {259},
number = {1},
pages = {250-255},
note = {cited By 14},
url = {https://www.sciencedirect.com/science/article/pii/S0168583X07002388?via%3Dihub},
doi = {https://doi.org/10.1016/j.nimb.2007.01.223}
}
|
2006 |
|
Ferromagnetic Ge(Mn) nanostructures S. Ahlers, D. Bougeard, H. Riedl, G. Abstreiter, A. Trampert, W. Kipferl, M. Sperl, A. Bergmaier and G. Dollinger; Physica E: Low-Dimensional Systems and Nanostructures 32 (1-2 SPEC. ISS.) (2006) 422-425. |
| Abstract: We present structural, magnetic and transport properties of Mn-doped Ge layers grown by molecular beam epitaxy (MBE) at low substrate temperatures TS. Atomic force microscopy (AFM), reflection high energy electron diffraction (RHEED) and transmission electron microscopy (TEM) analysis of structures grown at TS = 70 ring operator C and 120 ring operator C reveal defect-free epitaxy of Ge(Mn) on Ge(0 0 1) substrates. Despite the low TS we observe the formation of round shaped clusters with a diameter of 15-20 nm which are incoherent with the Ge matrix in TEM analysis for a Mn concentration x of 3.4%. SQUID measurements reveal ferromagnetism and a TC of around 300 ring operator C for the layers, reminiscent of the intermetallic compound Mn5 Ge3. Transport measurements, however, indicate that Mn is incorporated into the Ge matrix between the Mn5 Ge3 clusters as well. |
BibTeX:
@article{Ahlers2006,
author = {Ahlers, S. and Bougeard, D. and Riedl, H. and Abstreiter, G. and Trampert, A. and Kipferl, W. and Sperl, M. and Bergmaier, A. and Dollinger, G.},
title = {Ferromagnetic Ge(Mn) nanostructures},
journal = {Physica E: Low-Dimensional Systems and Nanostructures},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2006},
volume = {32},
number = {1-2 SPEC. ISS.},
pages = {422--425},
note = {cited By (since 1996)9},
url = {http://www.sciencedirect.com/science/article/pii/S1386947705005540},
doi = {https://doi.org/10.1016/j.physe.2005.12.129}
}
|
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The analysis of a thin SiO2/Si3N4/SiO2 stack: A comparative study of low-energy heavy ion elastic recoil detection, high-resolution Rutherford backscattering and secondary ion mass spectrometry B. Brijs, T. Sajavaara, S. Giangrandi, T. Janssens, T. Conard, K. Arstila, K. Nakajima, K. Kimura, A. Bergmaier, G. Dollinger, A. Vantomme and W. Vandervorst; Nuclear Instruments and Methods in Physics Research Section B 249 (1-2 SPEC. ISS.) (2006) 847-850. |
| Abstract: The analysis of thin films in the range of 10 nm and less has become very important in microelectronics. The goal of this article is an evaluation of low-energy TOF-ERDA (time-of-flight elastic recoil detection analysis) in comparison with low-energy SIMS (secondary ion mass spectrometry) and HRBS (high-resolution Rutherford backscattering spectrometry), using a thin SiO2/Si3N4/SiO2 stack as a test vehicle. Comparisons are made on the depth resolution, its loss as a function of depth and the quantification accuracy. |
BibTeX:
@article{Brijs2006,
author = {Brijs, B. and Sajavaara, T. and Giangrandi, S. and Janssens, T. and Conard, T. and Arstila, K. and Nakajima, K. and Kimura, K. and Bergmaier, A. and Dollinger, G. and Vantomme, A. and Vandervorst, W.},
title = {The analysis of a thin SiO2/Si3N4/SiO2 stack: A comparative study of low-energy heavy ion elastic recoil detection, high-resolution Rutherford backscattering and secondary ion mass spectrometry},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2006},
volume = {249},
number = {1-2 SPEC. ISS.},
pages = {847--850},
note = {cited By (since 1996)3},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X06004204},
doi = {https://doi.org/10.1016/j.nimb.2006.03.191}
}
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Design and advanced preparation of multilayer converters for ultracold-neutron detectors P. Maier-Komor, I. Altarev, A. Bergmaier, P. Böni, G. Dollinger, R. Krücken, S. Paul and W. Schott; Nuclear Instruments and Methods in Physics Research Section A 561 (1) (2006) 45-51. |
| Abstract: For experiments at the planned ultracold neutron (UCN) source of the new Munich research reactor (FRM II) highly efficient UCN detectors must be developed. The principle of this type of detector is the conversion of UCN in 6Li layers into 2.06 MeV α-particles and 2.73 MeV t-particles created in the reaction 6Li(n,α)t. Since the α- and t-particles are emitted in opposite direction, each reaction of a neutron with a 6Li atom could be identified, e.g. in a silicon PIN diode. The design of an UCN converter must take in account the high reflectance of UCN at 6Li with its positive optical potential. This must be compensated by a material with negative optical potential. Candidates for this are either 62Ni or 48Ti and as cheap compromise natTi. Since Ti and 6Li-metal can only be processed in an UHV plant without introducing disturbing oxygen impurities, the new multilayer stacks have been prepared all with 62Ni and 6LiF. One UCN converter with a stack of 125 double layers of 6LiF/62Ni was deposited on a 450 μg/cm2 rolled natTi backing foil. This was investigated by means of ERD analysis for its atomic concentration. These results are presented. A proposal is discussed where the backing foil is made from the neutron reflector material 58Ni. The required self-supporting 58Ni foil of 200-400 μg/cm2 thickness and a square area of 6.2 cm2 can be prepared by rolling. A UHV vacuum system for electron beam evaporation of Ti and 6Li is being assembled. Some annealing tests at another UHV system led to a modification of the planned pumping system. One of the three refrigerator cryopumps foreseen in the design has been replaced for a turbomolecular pump. Its gate valve is closed when annealing to 470 K is finished. |
BibTeX:
@article{Maier-Komor2006,
author = {Maier-Komor, P. and Altarev, I. and Bergmaier, A. and Böni, P. and Dollinger, G. and Krücken, R. and Paul, S. and Schott, W.},
title = {Design and advanced preparation of multilayer converters for ultracold-neutron detectors},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2006},
volume = {561},
number = {1},
pages = {45--51},
note = {cited By (since 1996)0},
url = {http://www.sciencedirect.com/science/article/pii/S0168900205026197},
doi = {https://doi.org/10.1016/j.nima.2005.12.226}
}
|
|
Preparation and investigation of thick carbon foils prepared by laser plasma ablation deposition P. Maier-Komor, G. Dollinger and R. Krücken; Nuclear Instruments and Methods in Physics Research Section A 561 (1) (2006) 4-10. |
| Abstract: Carbon foils prepared by laser plasma ablation deposition using a power density of >1 GW/cm² are so far the only ones which have been shown to have a total random orientation of the nanocrystallites and thus the theoretically best resistance against irradiation damage caused by ion bombardment. Need for longer lifetimes of carbon stripper foils was observed firstly in tandem accelerator experiments with heavy ions. There the required thickness is 3 to 10 μg/cm² and the plant was developed to meet these needs. Thicker carbon stripper foils are required as dead-section strippers and post-strippers. For the stripping of H- beams in the GeV range thick (> 100 μg/cm²) carbon stripper foils are required. The new plant which should facilitate the ablation deposition for this type of foils of unlimited thickness has been constructed. First results are presented about the preparation of thick (> 50 μg/cm²) carbon stripper foils of this kind and the applicability of the results to the preparation of carbon stripper foils of several hundred μg/cm² is discussed. For the application as gas detector windows very good chemical resistance is required if the carbon foil becomes hot due to the energy loss of the ion beam. Investigations for a 4 μg/cm² laser plasma carbon foil window transmitting 10 pμA of 3 MeV 12C2+ are reported. If very uniform electronic energy loss is required the corrugated structure, caused by the betaine parting agent on laser plasma carbon foils, is not suited. Therefore, it was tried to utilize release agents of different types of evaporated salt layers which were covered by 100μg/cm² copper in the same vacuum process. The floating success rates for those release agent combinations are reported. |
BibTeX:
@article{Maier-Komor2006a,
author = {Maier-Komor, P. and Dollinger, G. and Krücken, R.},
title = {Preparation and investigation of thick carbon foils prepared by laser plasma ablation deposition},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2006},
volume = {561},
number = {1},
pages = {4--10},
note = {cited By (since 1996)6},
url = {http://www.sciencedirect.com/science/article/pii/S0168900205026197},
doi = {https://doi.org/10.1016/j.nima.2005.12.184}
}
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Heavy ion irradiation of U-Mo/Al dispersion fuel N. Wieschalla, A. Bergmaier, P. Böni, K. Böning, G. Dollinger, R. Großmann, W. Petry, A. Röhrmoser and J. Schneider; Journal of Nuclear Materials 357 (1-3) (2006) 191-197. |
| Abstract: The usage of high-density U-Mo/Al dispersion fuel for high burn up in research and test reactors seems to be limited by the unfavourable interdiffusion layer between the fuel and the Al-matrix, which develops during irradiation. This interdiffusion layer was observed up to now only after costly and time consuming in-pile irradiation and could not be created in out-of-pile experiments. This paper presents a new approach of creating such an interdiffusion layer out-of-pile by irradiation with heavy ions. An appropriate choice of heavy-ion irradiation simulates irradiation damage and deposition of fission fragments as it happens during in-pile irradiation and induces a diffusion process between the fuel and the Al matrix. An irradiation experiment and post-irradiation examinations are presented. |
BibTeX:
@article{Wieschalla2006,
author = {Wieschalla, N. and Bergmaier, A. and Böni, P. and Böning, K. and Dollinger, G. and Großmann, R. and Petry, W. and Röhrmoser, A. and Schneider, J.},
title = {Heavy ion irradiation of U-Mo/Al dispersion fuel},
journal = {Journal of Nuclear Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2006},
volume = {357},
number = {1-3},
pages = {191--197},
note = {cited By (since 1996)12},
url = {http://www.sciencedirect.com/science/article/pii/S0022311506003679},
doi = {https://doi.org/10.1016/j.jnucmat.2006.06.006}
}
|
2005 |
|
The nucleation centers formed during bias-enhanced nucleation of diamond on iridium: Structure and stability S. Gsell, M. Schreck, T. Bauer, H. Karl, G. Thorwarth, A. Bergmaier, G. Dollinger and B. Stritzker; Diamond and Related Materials 14 (3-7) (2005) 328-334. |
| Abstract: During bias-enhanced nucleation (BEN) of diamond on iridium, an ultrathin carbon nucleation layer is deposited. The nature of the nucleation centers or nuclei which gather in discrete islands is investigated in the present work by subjecting the as-biased samples to different treatments. In high vacuum annealing experiments, the structures proved completely stable up to 1000°C. Above this temperature, the nuclei were destroyed and the iridium was etched within the domain areas. Low energy oxygen and xenon ion beams were then used to etch very shallow craters of varying depth. The induced modifications of the surface and the influence on the nucleation density can be understood on the basis of calculations which simulate the damage caused by the ion bombardment. Finally, the stability of the nucleation structures under hot chromo sulfuric acid treatment was compared with the corresponding behavior of a thick amorphous carbon layer. In all the experiments, the nucleation structures formed during BEN behaved similar to diamond situated at the surface of the iridium buffer layer possibly covered by a thin stable amorphous carbon layer. |
BibTeX:
@article{Gsell2005,
author = {Gsell, S. and Schreck, M. and Bauer, T. and Karl, H. and Thorwarth, G. and Bergmaier, A. and Dollinger, G. and Stritzker, B.},
title = {The nucleation centers formed during bias-enhanced nucleation of diamond on iridium: Structure and stability},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2005},
volume = {14},
number = {3-7},
pages = {328--334},
note = {cited By (since 1996)5},
url = {http://www.sciencedirect.com/science/article/pii/S0925963504003954},
doi = {https://doi.org/10.1016/j.diamond.2004.10.027}
}
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Highly Si-doped AlN grown by plasma-assisted molecular-beam epitaxy M. Hermann, F. Furtmayr, A. Bergmaier, G. Dollinger, M. Stutzmann and M. Eickhoff; Applied Physics Letters 86 (19) (2005) 1-3. |
| Abstract: We have studied the influence of the growth conditions on the Si incorporation in AlN films grown by plasma-assisted molecular-beam epitaxy. Nitrogen-rich growth conditions allow controlled incorporation of Si up to a concentration of 5.2× 1021 cm-3, determined by elastic recoil detection analysis, whereas Si incorporation is supressed under Al-rich growth conditions. The structural and morphological properties determined by x-ray diffraction and atomic force microscopy were not affected up to Si concentrations of 1.2× 1021 cm-3. The electrical conductivity for the N-rich growth regime first increases with Si concentration followed by a decrease due to an increase of the activation energy up to 570 meV for a Si content of 1.2× 1021 cm-3. For higher silicon concentrations, we have observed a sharp decrease in activation energy and an increase in conductivity by four orders of magnitude, attributed to the onset of impurity band conduction. |
BibTeX:
@article{Hermann2005,
author = {Hermann, M. and Furtmayr, F. and Bergmaier, A. and Dollinger, G. and Stutzmann, M. and Eickhoff, M.},
title = {Highly Si-doped AlN grown by plasma-assisted molecular-beam epitaxy},
journal = {Applied Physics Letters},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2005},
volume = {86},
number = {19},
pages = {1--3},
note = {cited By (since 1996)23},
url = {http://aip.scitation.org/doi/10.1063/1.1923180},
doi = {https://doi.org/10.1063/1.1923180}
}
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Optimization of thin, nitrogen-rich silicon oxynitrides grown by rapid thermal nitridation A. Ludsteck, J. Schulze, I. Eisele, W. Dietl, H. Chung, Z. Nenyei, A. Bergmaier and G. Dollinger; Journal of the Electrochemical Society 152 (5) (2005) G334-G338. |
| Abstract: We have systematically examined nitrogen-rich silicon oxynitrides with a thickness of about 2 nm grown by rapid thermal nitridation in ammonia. In this paper the nitrogen incorporation as well as the electrical properties of the oxynitrides are discussed in detail. With the help of elastic recoil detection measurements it could be shown that the incorporated nitrogen concentration can be controlled precisely in a range between 20 and 60%, which means that even pure silicon nitride can be thermally grown in ammonia. Depending on the process flow it is also possible to adjust the nitrogen and oxygen profiles across the dielectrics depth. Regarding the electrical properties of the grown oxynitrides, we examined the impact of the variation of the process parameters and the impact of postnitridation anneals. It was found that the dilution of the process gas ammonia by the inert gas argon has a big impact on the quality of the dielectric. The optimized oxynitrides show leakage current densities which are significantly reduced compared to that of SiO2, but their interface quality is not sufficient for metal oxide semiconductor (MOS) applications. In order to reduce the interface state density Dit, a short reoxidation in steam atmosphere combined with an anneal in forming gas results in oxynitrides with Dit values of 1011 eV-1 cm-2. It is shown that for an equivalent oxide thickness of 1.3-1.5 nm, the leakage current densities are four orders of magnitude below that of SiO2 with the same thickness. Promising measurements of the effective electron mobility show that the presented oxynitrides are suitable as gate dielectrics in MOS applications in spite of the high nitrogen concentration of more than 25%. |
BibTeX:
@article{Ludsteck2005,
author = {Ludsteck, A. and Schulze, J. and Eisele, I. and Dietl, W. and Chung, H. and Nenyei, Z. and Bergmaier, A. and Dollinger, G.},
title = {Optimization of thin, nitrogen-rich silicon oxynitrides grown by rapid thermal nitridation},
journal = {Journal of the Electrochemical Society},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2005},
volume = {152},
number = {5},
pages = {G334-G338},
note = {cited By (since 1996)3},
url = {http://jes.ecsdl.org/content/152/5/G334},
doi = {https://doi.org/10.1149/1.1872652}
}
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Nitrogen profile and electrical properties of reoxidized thermally grown silicon nitrides A. Ludsteck, J. Schulze, I. Eisele, W. Dietl, H. Chung, Z. Nényei, A. Bergmaier and G. Dollinger; In: , R.E. Sah, M.J. Deen, J. Zhang, J. Yota and Y. Kamakura (Eds.), ECS Meeting Abstracts 207 (2005) 232-241 , ECS - The Electrochemical Society. |
| Abstract: Starting from thermally grown Si3N4 we have examined the effects of dry and wet reoxidation in 100% O2 and H2O, respectively, in order to improve the electrical properties interface state density and tunneling current density of nitrogen-rich oxynitrides. It was found that only wet reoxidation can sufficiently improve them without too much increasing the equivalent oxide thickness. This result could be explained with the help of Elastic Recoil Detection measurements. We determined the exact oxygen and nitrogen profiles across the sample depth with a sub-nm resolution after nitridation as well as after different reoxidation steps. It was found that in the case of reoxidations in O2 both, longer times and higher temperatures are necessary in order to get oxygen at the SiOxN y/Si interface compared to the reoxidation in H2O. |
BibTeX:
@inproceedings{Ludsteck2005a,
author = {Ludsteck, A. and Schulze, J. and Eisele, I. and Dietl, W. and Chung, H. and Nényei, Z. and Bergmaier, A. and Dollinger, G.},
title = {Nitrogen profile and electrical properties of reoxidized thermally grown silicon nitrides},
booktitle = {ECS Meeting Abstracts},
publisher = {ECS - The Electrochemical Society},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2005},
volume = {207},
number = {412},
pages = {232--241},
editor = {Sah, R. E. and Deen, M. J. and Zhang, J. and Yota, J. and Kamakura, Y.},
note = {Film Preparation, Characterization, and Applications II - Abstract 412},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-31944437706&partnerID=40&md5=bec0de09644cecd68e6fe635a2e8b46d}
}
|
2004 |
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Physical characterization of mixed HfAlOx layers by complementary analysis techniques H. Bender, T. Conard, O. Richard, B. Brijs, J. Pétry, W. Vandervorst, C. Defranoux, P. Boher, N. Rochat, C. Wyon, P. Mack, J. Wolstenholme, R. Vitchev, L. Houssiau, J.-J. Pireaux, A. Bergmaier and G. Dollinger; Materials Science and Engineering B: Solid-State Materials for Advanced Technology 109 (1-3) (2004) 60-63. |
| Abstract: The combined information of complementary physical analysis techniques is applied to obtain a full characterisation of the important material parameters of new high-k layers, i.e. the layer thickness, density, composition and interlayer thickness and nature, and to optimise the measurement methodologies of the different techniques. |
BibTeX:
@article{Bender2004,
author = {Bender, H. and Conard, Th. and Richard, O. and Brijs, B. and Pétry, J. and Vandervorst, W. and Defranoux, C. and Boher, P. and Rochat, N. and Wyon, C. and Mack, P. and Wolstenholme, J. and Vitchev, R. and Houssiau, L. and Pireaux, J.-J. and Bergmaier, A. and Dollinger, G.},
title = {Physical characterization of mixed HfAlOx layers by complementary analysis techniques},
journal = {Materials Science and Engineering B: Solid-State Materials for Advanced Technology},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2004},
volume = {109},
number = {1-3},
pages = {60--63},
editor = {Dimoulas A., Fompeyrine J., Fanciulli M., Alexe M., Os H.J.},
note = {cited By (since 1996)6},
url = {http://www.sciencedirect.com/science/article/pii/S092151070300518X},
doi = {https://doi.org/10.1016/j.mseb.2003.10.118}
}
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High resolution elastic recoil detection G. Dollinger, A. Bergmaier, L. Goergens, P. Neumaier, W. Vandervorst and S. Jakschik; Nuclear Instruments and Methods in Physics Research Section B 219-220 (1-4) (2004) 333-343. |
| Abstract: The quantitative analysis of light elements in ultra thin films being thinner than 10 nm is still a nontrivial task. This paper will summarise the prospects of high resolution elastic recoil detection (ERD) using a Q3D magnetic spectrograph. It has been shown that subnanometer resolution can be achieved in ultra thin films and even monolayer resolution is possible close to the surface. ERD has best quantification possibilities compared to any other method. Sensitivity is sufficient to analyse main elements and impurities as e.g. being necessary for the characterisation of microelectronic materials. In addition, high resolution channeling ERD can be performed in order to get information on lattice location of light elements in crystalline ultra thin layers. The potential of high resolution ERD will be demonstrated by several applications where it is the most valuable tool for elemental profiling. |
BibTeX:
@article{Dollinger2004,
author = {Dollinger, G. and Bergmaier, A. and Goergens, L. and Neumaier, P. and Vandervorst, W. and Jakschik, S.},
title = {High resolution elastic recoil detection},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2004},
volume = {219-220},
number = {1-4},
pages = {333--343},
editor = {Vizkelethy G., McDaniel F.D., Thevuthasan S., Tesmer J.R.},
note = {cited By (since 1996)16},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X04001077},
doi = {https://doi.org/10.1016/j.nimb.2004.01.079}
}
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Physical properties of ALD-Al2O3 in a DRAM-capacitor equivalent structure comparing interfaces and oxygen precursors S. Jakschik, U. Schroeder, T. Hecht, G. Dollinger, A. Bergmaier and J. Bartha; Materials Science and Engineering B: Solid-State Materials for Advanced Technology 107 (3) (2004) 251-254. |
| Abstract: Aluminum oxide was deposited on arsenic doped silicon, using atomic layer deposition (ALD) with either a silicon oxide or a silicon nitride interface. The physical properties of these films were investigated by elastic-recoil-detection, X-ray-photoelectron-spectroscopy and transmission electron microscopy. Special focus was given to contamination of the film and the interface, crystallization and temperature effect on diffusion. The films remained stoichiometric and did not have Al-Al clusters, even post annealing steps. Evidence of diffusion of silicon and arsenic into the dielectric and of aluminum from the film was found. Carbon and hydrogen were seen in the film and at the interface as well, whereas hydrogen diffused out of the film to some extent due to anneal. Carbon content in the layer was reduced by using O 3 as oxidant. Grain size of crystalline Al2O3 films was in the order of film thickness. |
BibTeX:
@article{Jakschik2004,
author = {Jakschik, S. and Schroeder, U. and Hecht, T. and Dollinger, G. and Bergmaier, A. and Bartha, J.W.},
title = {Physical properties of ALD-Al2O3 in a DRAM-capacitor equivalent structure comparing interfaces and oxygen precursors},
journal = {Materials Science and Engineering B: Solid-State Materials for Advanced Technology},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2004},
volume = {107},
number = {3},
pages = {251--254},
note = {cited By (since 1996)11},
url = {http://www.sciencedirect.com/science/article/pii/S0921510703004835},
doi = {https://doi.org/10.1016/j.mseb.2003.09.044}
}
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Doping and its efficiency in a-SiOx:H A. Janotta, R. Janssen, M. Schmidt, T. Graf, M. Stutzmann, L. Görgens, A. Bergmaier, G. Dollinger, C. Hammerl, S. Schreiber and B. Stritzker; Physical Review B - Condensed Matter and Materials Physics 69 (11) (2004) 1152061-11520616. |
| Abstract: Amorphous hydrogenated silicon suboxides (a-SiOx:H) deposited by plasma enhanced chemical vapor deposition have a band gap which can be tuned from 1.9 to 3.0 eV by varying the oxygen content [O] from 0 to 50 at. %. n- and p-type doping is realized by adding PH3 and B2H 6, respectively, to the source gases SiH4, H2, and CO2. Alloying with increasing amounts of oxygen reduces the average coordination number 〈r〉 from a value close to 4 (a-Si:H) to ≈2.7, which gradually approaches the ideal value of 〈r〉=2.4 for network glasses. This goes along with a softening of the amorphous SiO x network, i.e., a reduction of the mechanical hardness of the material, which is also predicted by rigidity percolation theory. Also the incorporation of dopant atoms into electrically active, fourfold coordinated sites becomes more unlikely with increasing [O]. As a consequence, n- and p-type doped SiOx shows increasingly intrinsic character for higher oxygen concentrations. Doping fails for values of 〈r〉<3 and the doping efficiency tends towards zero. Thus, an overall fourfold coordination was found to be a crucial requirement for efficient doping in amorphous semiconductors. |
BibTeX:
@article{Janotta2004,
author = {Janotta, A. and Janssen, R. and Schmidt, M. and Graf, T. and Stutzmann, M. and Görgens, L. and Bergmaier, A. and Dollinger, G. and Hammerl, C. and Schreiber, S. and Stritzker, B.},
title = {Doping and its efficiency in a-SiOx:H},
journal = {Physical Review B - Condensed Matter and Materials Physics},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2004},
volume = {69},
number = {11},
pages = {1152061-11520616},
note = {cited By (since 1996)20},
url = {http://journals.aps.org/prb/abstract/10.1103/PhysRevB.69.115206},
doi = {https://doi.org/10.1103/PhysRevB.69.115206}
}
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Antireflection foils with multi-layer converter for ultracold neutron detectors P. Maier-Komor, I. Altarev, A. Bergmaier, P. Böni, G. Dollinger, R. Krücken, S. Paul and W. Schott; Nuclear Instruments and Methods in Physics Research Section A 521 (1) (2004) 242-246. |
| Abstract: For experiments at the ultracold neutron (UCN) source of the new high-luminosity neutron source, Forschungsreaktor München II (FRM II), highly efficient detectors are needed. The desired type of detectors utilizes 6Li as the neutron converter based on the huge cross-section reaction 6Li(n,α)t and detection of the 2.06MeV α-particles or the 2.73MeV t-particles. The high reflectance of UCN from 6Li with its positive optical potential must be compensated by a material with negative optical potential. Instead of the expensive 62Ni material, natural Ti can be chosen. It was demonstrated that neither 6Li metal nor Ti metal can be deposited in a high-vacuum evaporation apparatus without creating a positive optical potential and thus increasing the reflectivity for the UCN due to oxygen impurities coming from the H2O partial pressure in the high-vacuum system. To overcome these problems, a new UHV evaporation apparatus was developed and built which is capable of reaching a vacuum in the 10-10 Pa range. Such a good vacuum can be obtained only when annealing the vacuum system up to 470K. At such a high annealing temperature the silicon detectors for the α- and t particles might suffer degradation of their energy resolution. Therefore, the multi-layer system of 6Li and natTi is not deposited directly on the silicon detector but a thin rolled Ti foil is applied as backing. A test deposition of 200 double layers of 6LiF/ 62Ni on a thin Ti foil is described and a report is given about the setup of the new UHV evaporation apparatus. |
BibTeX:
@article{Maier-Komor2004,
author = {Maier-Komor, P. and Altarev, I. and Bergmaier, A. and Böni, P. and Dollinger, G. and Krücken, R. and Paul, S. and Schott, W.},
title = {Antireflection foils with multi-layer converter for ultracold neutron detectors},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2004},
volume = {521},
number = {1},
pages = {242--246},
editor = {Green J.P., Maier-Komor P.},
note = {cited By (since 1996)1},
url = {http://www.sciencedirect.com/science/article/pii/S0168900203030936},
doi = {https://doi.org/10.1016/j.nima.2003.11.179}
}
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A new UHV system for the preparation of carbon stripper foils by laser plasma ablation deposition P. Maier-Komor, G. Dollinger and R. Krücken; Nuclear Instruments and Methods in Physics Research Section A 521 (1) (2004) 176-182. |
| Abstract: Laser plasma ablation of spectroscopically pure graphite under UHV conditions is a well established method for the preparation of thin carbon stripper foils. Such foils with their structure of randomly oriented nanocrystallites can best withstand ion irradiation damage. Accelerator users around the world are interested in this type of carbon stripper foils due to a guaranteed reproducibility, quality, thickness and uniformity given by the procedure. In addition a high reproducible yield with a low effort for floating, mounting and slackening is desired. Users of high-energy accelerators want to profit from this development, but need stripper foils of up to 500 μg/cm 2 for the relevant charge state equilibrium whereas carbon foils of this type could only be prepared with an upper limit of 10 μg/cm2 in the existing set up. The new design was aimed to overcome all thickness limitations. The crucial component of the laser plasma ablation technique is the laser entrance window which becomes opaque during carbon ablation. A new plant which overcomes this problem is being assembled. Due to a higher source-to-window distance and a better laser light transmission, caused by slightly changed laser plasma conditions, the life of the laser entrance window before exchange could be prolonged by a factor of five. Presumably, there are no thickness limitations anymore due to a vacuum interlock that permits the exchange of the entrance window without breaking the vacuum in the ablation-deposition chamber. |
BibTeX:
@article{Maier-Komor2004a,
author = {Maier-Komor, P. and Dollinger, G. and Krücken, R.},
title = {A new UHV system for the preparation of carbon stripper foils by laser plasma ablation deposition},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2004},
volume = {521},
number = {1},
pages = {176--182},
editor = {Green J.P., Maier-Komor P.},
note = {cited By (since 1996)4},
url = {http://www.sciencedirect.com/science/article/pii/S016890020303081X},
doi = {https://doi.org/10.1016/j.nima.2003.11.148}
}
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Errors in near-surface and interfacial profiling of boron and arsenic W. Vandervorst, T. Janssens, B. Brijs, T. Conard, C. Huyghebaert, J. Frühauf, A. Bergmaier, G. Dollinger, T. Buyuklimanli, J. VandenBerg and K. Kimura; Applied Surface Science 231-232 (2004) 618-631. |
| Abstract: To get an insight in the diffusion behavior of dopants such as arsenic and boron after annealing and in particular their segregation characteristics towards the interface in oxide structures on silicon, it is necessary to probe the dopant profile with very high accuracy and depth resolution. Sputter depth profiling as employed in secondary ion mass spectrometry (SIMS) is frequently used as the most suited tool for dopant profiling in view of its sensitivity and depth resolution. However in order to determine the segregated arsenic/boron peak, sub-nanometer depth resolution is required and artifacts such as beam induced broadening effects, potential ionization yield changes at interfaces, transient sputter yields need to be considered in detail. When reducing the primary beam energy the depth resolution can be improved and sub-nanometer depth sensitivity can be demonstrated. However comparisons with high resolution elastic recoil detection analysis demonstrate that it is at present impossible to obtain a reliable depth profile in the first nanometer near the surface nor even in the oxide part of the profile, where no ionization nor sputter yield transients are expected. Enhanced beam induced migration of boron during the initial phase of the bombardment needs to be invoked to explain the results. The latter appears to be enhanced under conditions (∼normal incidence) where full oxidation occurs. |
BibTeX:
@article{Vandervorst2004,
author = {Vandervorst, W. and Janssens, T. and Brijs, B. and Conard, T. and Huyghebaert, C. and Frühauf, J. and Bergmaier, A. and Dollinger, G. and Buyuklimanli, T. and VandenBerg, J.A. and Kimura, K.},
title = {Errors in near-surface and interfacial profiling of boron and arsenic},
journal = {Applied Surface Science},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2004},
volume = {231-232},
pages = {618--631},
note = {cited By (since 1996)36},
url = {http://www.sciencedirect.com/science/article/pii/S0169433204003630},
doi = {https://doi.org/10.1016/j.apsusc.2004.03.125}
}
|
2003 |
|
Diamond diodes and transistors A. Aleksov, A. Denisenko, M. Kunze, A. Vescan, A. Bergmaier, G. Dollinger, W. Ebert and E. Kohn; Semiconductor Science and Technology 18 (3) (2003) 59-S66. |
| Abstract: Over the past few years a variety of diamond electron devices have been fabricated, analysed and simulated. This includes Schottky diodes on boron-doped p+ diamond substrates, boron/nitrogen pn-junction diodes, bipolar transistors based on this pn-junction and field effect transistors (FETs) with boron delta-doped channels and hydrogen-related surface conductive layers. Many of the fabricated devices considered here represent the current state-of-the-art in this field. This includes the operation of diamond Schottky diodes at temperatures of up to 1000 °C, as well as diamond FET devices with a cut-off frequency of 30 GHz and channel current densities of 300 mA mm-1. Simulations show that diamond boron delta-doped FETs might yield an RF-output power density of up to 30 W mm-1. |
BibTeX:
@article{Aleksov2003,
author = {Aleksov, A. and Denisenko, A. and Kunze, M. and Vescan, A. and Bergmaier, A. and Dollinger, G. and Ebert, W. and Kohn, E.},
title = {Diamond diodes and transistors},
journal = {Semiconductor Science and Technology},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003},
volume = {18},
number = {3},
pages = {59-S66},
note = {cited By (since 1996)40},
url = {http://iopscience.iop.org/article/10.1088/0268-1242/18/3/308/meta},
doi = {https://doi.org/10.1088/0268-1242/18/3/308}
}
|
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Diamond field effect transistors - Concepts and challenges A. Aleksov, M. Kubovic, N. Kaeb, U. Spitzberg, A. Bergmaier, G. Dollinger, T. Bauer, M. Schreck, B. Stritzker and E. Kohn; Diamond and Related Materials 12 (3-7) (2003) 391-398. |
| Abstract: Field effect transistors (FETs) in diamond should outperform FET structures on other wide bandgap materials like SiC and GaN in high power/high temperature applications due to the ideal diamond materials properties. However, the technology of these structures proved difficult leaving two device concepts to investigate: (1) the boron δ-doped p-channel FET and (2) the hydrogen induced p-type surface-channel-FET. The δ-channel-FET approach follows a traditional design path of power FET structures. Here, simulation results have enabled the extrapolation of a maximum RF output power to 27 W/mm, a value which is indeed higher than for any FET based on III-Nitrides or SiC. However, due to the narrow technological parameter window, fabricated δ-channel-FETs are still well behind expectations. In contrast, concerning the surface-channel-FET the physical/chemical nature of its channel remains still under discussion. Nevertheless, results obtained with this FET concept yielded a VDmax > 200 V (LG = 1 μm) and a IDmax > 360 mA/mm a fT = 11.5 GHz and fmaxU > 40 GHz (LG = 0.2 μm) and a recently obtained RF power measurement at 1 GHz. Furthermore, the 1 GHz power measurement result has been obtained on a diamond quasi-substrate grown on a Ir/SrTiO3 substrate. This result may therefore open up the perspective for wafer scale diamond electronics. |
BibTeX:
@article{Aleksov2003a,
author = {Aleksov, A. and Kubovic, M. and Kaeb, N. and Spitzberg, U. and Bergmaier, A. and Dollinger, G. and Bauer, Th. and Schreck, M. and Stritzker, B. and Kohn, E.},
title = {Diamond field effect transistors - Concepts and challenges},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003},
volume = {12},
number = {3-7},
pages = {391--398},
note = {cited By (since 1996)62},
url = {http://www.sciencedirect.com/science/article/pii/S0925963502004016},
doi = {https://doi.org/10.1016/S0925-9635(02)00401-6}
}
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Physical characterization of thin HfO2 layers by the combined analysis with complementary techniques H. Bender, T. Conard, O. Richard, B. Brijs, J. Pétry, W. Vandervorst, C. Defranoux, P. Boher, N. Rochat, C. Wyon, P. Mack, J. Wolstenholme, R. Vitchev, L. Houssiau, J.-J. Pireaux, A. Bergmaier and G. Dollinger; In: , B.O. Kolbesen, C. Claeys, P. Stallhofer, F. Tardif, D.K. Schroder, T.J. Shaffner, M. Tajima and P. Rai Choudhury (Eds.), Proceedings of SPIE - The International Society for Optical Engineering 5133 (2003) 223-232 , SPIE. |
| Abstract: The physical properties of HfO2 layers prepared by atomic layer and metal organic chemical vapor deposition (MOCVD) were analyzed. A combination of different complementary analysis techniques was used during the analysis. A similar deposition time dependence was found for the MOCVD layers deposited at 300 and 485° C. It was shown that the density increases with the number of deposition cycles for the atomic layer deposition (ALD) layers. |
BibTeX:
@inproceedings{Bender2003,
author = {Bender, H. and Conard, Th. and Richard, O. and Brijs, B. and Pétry, J. and Vandervorst, W. and Defranoux, Chr. and Boher, P. and Rochat, N. and Wyon, C. and Mack, P. and Wolstenholme, J. and Vitchev, R. and Houssiau, L. and Pireaux, J.-J. and Bergmaier, A. and Dollinger, G.},
title = {Physical characterization of thin HfO2 layers by the combined analysis with complementary techniques},
booktitle = {Proceedings of SPIE - The International Society for Optical Engineering},
publisher = {SPIE},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003},
volume = {5133},
pages = {223--232},
editor = {Kolbesen, B. O. and Claeys, C. and Stallhofer, P. and Tardif, F. and Schroder, D. K. and Shaffner, T. J. and Tajima, M. and Rai - Choudhury, P.},
note = {Analytical and Diagnostic Techniques for Semiconductor Materials, Devices, and Processes; Salt Lake City, UT; United States; 21 October 2002 through 25 October 2002},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0242468973&partnerID=40&md5=1c49e313f7666ce84bbd5ef30b1e189d}
}
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Recent developments in nuclear methods in support of semiconductor characterization B. Brijs, H. Bender, C. Huyghebaert, T. Janssens, W. Vandervorst, K. Nakajima, K. Kimura, A. Bergmaier, G. Dollinger and J. Van den Berg; In: , B.O. Kolbesen, C. Claeys, P. Stallhofer, F. Tardif, D.K. Schroder, T.J. Shaffner, M. Tajima and P. Rai Choudhury (Eds.), Proceedings of SPIE - The International Society for Optical Engineering 5133 (2003) 50-62 , SPIE. |
| Abstract: The analysis of thin materials related to semiconductors using nuclear techniques was presented. Decreasing the beam energy from the conventional energy of 2 MeV to lower than 0.5 MeV or lower transforms rutherford backscattering (RBS) to a near surface analysis technique. It was concluded that problems of material characterization could be solved using secondary ion mass spectrometry (SIMS) and dedicated nuclear techniques that provide good insight in the material behavior in shallow layers. |
BibTeX:
@inproceedings{Brijs2003,
author = {Brijs, B. and Bender, H. and Huyghebaert, C. and Janssens, T. and Vandervorst, W. and Nakajima, K. and Kimura, K. and Bergmaier, A. and Dollinger, G. and Van den Berg, J.A.},
title = {Recent developments in nuclear methods in support of semiconductor characterization},
booktitle = {Proceedings of SPIE - The International Society for Optical Engineering},
publisher = {SPIE},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003},
volume = {5133},
pages = {50--62},
editor = {Kolbesen, B. O. and Claeys, C. and Stallhofer, P. and Tardif, F. and Schroder, D. K. and Shaffner, T. J. and Tajima, M. and Rai - Choudhury, P.},
note = {Analytical and Diagnostic Techniques for Semiconductor Materials, Devices, and Processes; Salt Lake City, UT; United States; 21 October 2002 through 25 October 2002},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0242497089&partnerID=40&md5=20345bca5db47484b0f8807dfe96affa}
}
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Characterization of the b and as pile-up at the si-sio2 interface J. Frühauf, R. Lindsay, A. Bergmaier, G. Dollinger, W. Vandervorst, K. Maex and F. Koch; In: Ultra Shallow Junctions. 7th Int. Worksh. Fabrication, Characterization and Modeling of Ultra Shallow Doping Profiles in Semic. (2003) . [BibTeX] |
BibTeX:
@inproceedings{Fruehauf2003,
author = {Frühauf, J. and Lindsay, R. and Bergmaier, A. and Dollinger, G. and Vandervorst, W. and Maex, K. and Koch, Frederick},
title = {Characterization of the b and as pile-up at the si-sio2 interface},
booktitle = {Ultra Shallow Junctions. 7th Int. Worksh. Fabrication, Characterization and Modeling of Ultra Shallow Doping Profiles in Semic.},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003}
}
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Physical characterization of thin ALD-Al2O3 films S. Jakschik, U. Schroeder, T. Hecht, D. Krueger, G. Dollinger, A. Bergmaier, C. Luhmann and J. Bartha; Applied Surface Science 211 (1-4) (2003) 352-359. |
| Abstract: Aluminum oxide was deposited using atomic layer deposition on either a silicon oxide or a silicon nitride interface. Water vapor or ozone were used as oxidation precursors. The structural properties of these films were investigated by time-of-flight secondary-ion-mass-spectroscopy (ToF-SIMS), X-ray photoelectron spectroscopy (XPS) and elastic recoil detection (ERD). Special attention was given to contamination issues of the film and the interface, bonding conditions and temperature influence on diffusion. The results suggest that the silicon most likely diffused along grain boundaries of polycrystalline Al2O3. Carbon and hydrogen were located at the interface and furthermore hydrogen diffused out of the film to some extent due to anneal. Carbon content in the layer was reduced when using O3 as an oxidant. The formation of metallic aluminum clusters was not observed for any of the investigated process conditions. |
BibTeX:
@article{Jakschik2003,
author = {Jakschik, S. and Schroeder, U. and Hecht, T. and Krueger, D. and Dollinger, G. and Bergmaier, A. and Luhmann, C. and Bartha, J.W.},
title = {Physical characterization of thin ALD-Al2O3 films},
journal = {Applied Surface Science},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003},
volume = {211},
number = {1-4},
pages = {352--359},
note = {cited By (since 1996)36},
url = {http://www.sciencedirect.com/science/article/pii/S0169433203002642},
doi = {https://doi.org/10.1016/S0169-4332(03)00264-2}
}
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Diffusion in diamond-like carbon H. Kröger, C. Ronning, H. Hofsäss, P. Neumaier, A. Bergmaier, L. Görgens and G. Dollinger; Diamond and Related Materials 12 (10-11) (2003) 2042-2050. |
| Abstract: The diffusion of carbon and five other elements in amorphous carbon (a-C) films was studied. One set of samples were sp2 dominated a-C and the other set of samples were sp3 dominated tetrahedral amorphous carbon (ta-C). The films were deposited using mass separated ion beam deposition under UHV conditions. The diffusion of 13C as well as that of hydrogen and deuterium was studied using high resolution elastic recoil detection analysis. No apparent self-diffusion could be detected using this technique. The diffusion of hydrogen was found to start at temperatures between 600 and 800 °C. For deuterium, activation energies of 3.34(5) and 3.39(5) eV were found for diffusion in ta-C and a-C, respectively. Tungsten, copper and silver were used to study the diffusion of metals in ta-C. Up to annealing temperatures of 1000 °C no diffusion took place in the samples. During annealing at 1200 °C the ta-C is converted into graphite, making diffusion into the carbon matrix possible. The fact that there is no diffusion of copper in ta-C at temperatures below 1200 °C shows that ta-C is a possible diffusion barrier between copper and silicon. |
BibTeX:
@article{Kroeger2003,
author = {Kröger, H. and Ronning, C. and Hofsäss, H. and Neumaier, P. and Bergmaier, A. and Görgens, L. and Dollinger, G.},
title = {Diffusion in diamond-like carbon},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003},
volume = {12},
number = {10-11},
pages = {2042-2050},
note = {cited By (since 1996)12},
url = {http://www.sciencedirect.com/science/article/pii/S0925963503002188},
doi = {https://doi.org/10.1016/S0925-9635(03)00218-8}
}
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Cooling and heating of channeled ions and corresponding charge state distributions M. Schubert, F. Grüner, W. Assmann, F. Bell, A. Bergmaier, L. Goergens, O. Schmelmer, G. Dollinger and S. Karamian; Nuclear Instruments and Methods in Physics Research Section B 209 (2003) 224-232. |
| Abstract: Our group has recently [Phys. Rev. Lett., 83 (1999) 1759] reported experimental evidence for the redistribution of an isotropic ion flux after transmission through thin crystals. For not fully stripped ions we have observed either an enhancement (cooling) or a reduction (heating) of the angular flux along crystal directions. For a possible explanation of this unpredicted effect an additional mechanism was introduced: cooling or heating of the transverse motion by spatially correlated charge exchange processes. One consequence of this mechanism could be a different charge state distribution of well-channeled versus non-channeled ions: for cooling channeled ions should exit the crystal with a higher charge state than in random directions and heating should yield the opposite result. We report here measurements that show indeed shifts of the mean charge state of channeled ions in comparison to the one of random ions. These shifts depend on the ion velocity, but there seems to be no general correlation between the shifts and the appearance of cooling or heating. © 2003 Elsevier B.V. All rights reserved. |
BibTeX:
@article{Schubert2003,
author = {Schubert, M. and Grüner, F. and Assmann, W. and Bell, F. and Bergmaier, A. and Goergens, L. and Schmelmer, O. and Dollinger, G. and Karamian, S.},
title = {Cooling and heating of channeled ions and corresponding charge state distributions},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003},
volume = {209},
pages = {224--232},
editor = {Marletta G., Bouffard S., Neumann R.},
note = {cited By (since 1996)7},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X02020384},
doi = {https://doi.org/10.1016/S0168-583X(02)02038-4}
}
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Growth and properties of CVD diamond films grown under H2S addition H. Sternschulte, M. Schreck, B. Stritzker, A. Bergmaier and G. Dollinger; Diamond and Related Materials 12 (3-7) (2003) 318-323. |
| Abstract: The influence of H2S on the CVD diamond growth, the sulfur incorporation and the electronic properties of sulfur containing homoepitaxial diamond films were studied. Laser reflection interferometry (LRI) in combination with mass spectroscopy (MS) showed that H2S modifies the gas phase chemistry by reducing the concentration of CHx species. As a consequence thereof, at high deposition temperatures the growth rate decreased. At lower substrate temperatures, the observed increase in the growth rate after sulfur addition indicates that these gas phase effects are overcompensated by processes at the growing diamond surface. The incorporation coefficient of sulfur into the definitely boron free diamond films was very low (less than 10-6). Incorporation seems to be enhanced by a reduction of the substrate temperature, by the presence of Si and, most effectively, by addition of CO2. For 0.5% CO2 in the gas mixture a maximum S concentration of 480 ppm (9 × 1019/cm3) corresponding to an incorporation coefficient of 6 × 10-4 was attained. Even for the highest H2S concentrations (nearly 1%) the deposited diamond films preserve their excellent quality as judged from μ-Raman measurements. The electrical properties were not changed by the S incorporation. The electrical conductivity is thermally activated with typically 1.4-1.5 eV independent from the S concentration in the films. No values below 1.0 eV have been measured which argues against doping. © 2002 Elsevier Science B.V. All rights reserved. |
BibTeX:
@article{Sternschulte2003,
author = {Sternschulte, H. and Schreck, M. and Stritzker, B. and Bergmaier, A. and Dollinger, G.},
title = {Growth and properties of CVD diamond films grown under H2S addition},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003},
volume = {12},
number = {3-7},
pages = {318--323},
note = {cited By (since 1996)15},
url = {http://www.sciencedirect.com/science/article/pii/S0169433202006785},
doi = {https://doi.org/10.1016/S0925-9635(02)00312-6}
}
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An (un)solvable problem in SIMS: B-interfacial profiling W. Vandervorst, T. Janssens, R. Loo, M. Caymax, I. Peytier, R. Lindsay, J. Frühauf, A. Bergmaier and G. Dollinger; Applied Surface Science 203-204 (2003) 371-376. |
| Abstract: To get an insight in the diffusion behavior of boron after annealing and in particular its segregation characteristics towards the interface in oxide structures on silicon, it is necessary to probe the boron profile with very high accuracy and depth resolution. Sputter depth profiling as employed in secondary ion mass spectrometry (SIMS) is frequently used as the most suited tool for dopant profiling in view of its sensitivity and depth resolution. However, in order to determine the segregated boron peak, sub-nm depth resolution is required and artifacts such as beam induced broadening effects, potential ionization yield changes at interfaces, transient sputter yields need to be considered in detail. When reducing the primary beam energy the depth resolution can be improved and sub-nm depth sensitivity can be demonstrated. However, comparisons with high-resolution elastic recoil detection analysis demonstrate that even under those conditions no reliable depth profile can be obtained in the first nm near the surface nor even in the oxide part of the profile, where no ionization nor sputter yield transients are expected. Enhanced beam induced migration of boron during the initial phase of the bombardment needs to be invoked to explain the results. |
BibTeX:
@article{Vandervorst2003,
author = {Vandervorst, W. and Janssens, T. and Loo, R. and Caymax, M. and Peytier, I. and Lindsay, R. and Frühauf, J. and Bergmaier, A. and Dollinger, G.},
title = {An (un)solvable problem in SIMS: B-interfacial profiling},
journal = {Applied Surface Science},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2003},
volume = {203-204},
pages = {371--376},
note = {cited By (since 1996)21},
url = {http://www.sciencedirect.com/science/article/pii/S0169433202006785},
doi = {https://doi.org/10.1016/S0169-4332(02)00678-5}
}
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2002 |
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Analysis of the total carbon deposition during the bias enhanced nucleation of diamond on Ir/SrTiO3 (001) using 13C-methane T. Bauer, M. Schreck, F. Hörmann, A. Bergmaier, G. Dollinger and B. Stritzker; Diamond and Related Materials 11 (3-6) (2002) 493-498. |
| Abstract: Carbon deposition during bias enhanced nucleation (BEN) of diamond on Ir/SrTiO3 (001) was measured by elastic recoil detection (ERD) analysis using 13C-methane in the process gas. High resolution optical emission spectra (OES) of CH emission lines from the gas phase as well as Raman spectra of deposited diamond films showed the high isotopic purity of the reaction gas. During the biasing step a carbon coverage of approximately 1 × 1016 cm-2 equivalent to a 0.6-nm-thick diamond layer was deposited at the surface after 45 min. Its thickness only increased slowly for longer biasing. A similar carbon enrichment was also found at the iridium/SrTiO3 interface. After the nucleation step, nanometer-size particles of very uniform height were found at the iridium surface. Their integral volume was more than an order of magnitude lower than the total volume of the carbon layer present at the surface after BEN. Our experiments indicate that most of the carbon is continuously distributed over the surface which allows to sketch a rough image of the processes occurring during BEN on iridium. |
BibTeX:
@article{Bauer2002,
author = {Bauer, Th. and Schreck, M. and Hörmann, F. and Bergmaier, A. and Dollinger, G. and Stritzker, B.},
title = {Analysis of the total carbon deposition during the bias enhanced nucleation of diamond on Ir/SrTiO3 (001) using 13C-methane},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2002},
volume = {11},
number = {3-6},
pages = {493--498},
note = {cited By (since 1996)17},
url = {http://www.sciencedirect.com/science/article/pii/S0925963501006264},
doi = {https://doi.org/10.1016/S0925-9635(01)00626-4}
}
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Advanced characterization of high-k materials: A nuclear approach B. Brijs, C. Huyghebaert, S. Nauwelaerts, M. Caymax, W. Vandervorst, K. Nakajima, K. Kimura, A. Bergmaier, G. Dollinger G.llinger, W. Lennard, G. Terwagne and A. Vantomme; Nuclear Instruments and Methods in Physics Research Section B 190 (1-4) (2002) 505-509. |
| Abstract: The determination of the composition of thin (1.5-3 nm) high-k layers ZrO2/Al2O3 becomes more and more important in microelectronics. High resolution Rutherford backscattering spectrometry and high resolution elastic recoil detection can achieve depth resolutions down to 1 nm while Rutherford backscattering spectrometry and nuclear reaction analysis are perfectly suited to quantify the zirconium, the oxygen and the aluminum content. The goal of this paper is to investigate the use of nuclear techniques for the characterization of thin high-k materials. |
BibTeX:
@article{Brijs2002,
author = {Brijs, B. and Huyghebaert, C. and Nauwelaerts, S. and Caymax, M. and Vandervorst, W. and Nakajima, K. and Kimura, K. and Bergmaier, A. and Dollinger, G.llinger, G. and Lennard, W.N. and Terwagne, G. and Vantomme, A.},
title = {Advanced characterization of high-k materials: A nuclear approach},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2002},
volume = {190},
number = {1-4},
pages = {505--509},
note = {cited By (since 1996)6},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X02004688},
doi = {https://doi.org/10.1016/S0168-583X(02)00468-8}
}
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Electrical activity of B and As segregated at the Si-SiO2 interface J. Frühauf, R. Lindsay, A. Bergmaier, W. Vandervorst, G. Tempel, K. Maex, G. Dollinger and F. Koch; In: , D.F. Downey, M.E. Law, A. Claverie and M.J. Rendon (Eds.), Silicon Front-End Junction Formation Technologies; San Francisco, CA; United States; 2 -4 April 2002 717 (2002) 115-120 , Materials Research Society. |
| Abstract: During spike annealing of ultra-shallow junctions, large fractions of the dopants form a partially active pile-up at the interface between silicon and the screening oxide layer. In this paper, we show results of sheet resistance, SIMS and high resolution Elastic Recoil Detection measurements to investigate the physical and electrical behaviour of B and As dopant atoms at the interface. Our results show that the fraction of dopants segregated at the interface is as high as 30-50% for B, but is dependent on dose and the type of screening oxide. Concentrations of up to 3e20 cm-3 and more of active dopants are found on the Si side of the interface. The presence of nitrogen in the oxide at the interface causes a higher and sharper pile-up. Results indicate that a similar peak is expected for As, with active concentrations above 6e20 cm-3. In an HF dip, the pile-up is removed together with the oxide or deactivated during native oxide regrowth. Further experiments show that immediately after removing the screening oxide in an HF dip the sheet resistance for B decreases sharply due to carrier accumulation, then raises to about 6-9% above the initial level depending on the oxide and dopant species. The sharp decrease in resistance is not observed for As. |
BibTeX:
@inproceedings{Fruehauf2002,
author = {Frühauf, J. and Lindsay, R. and Bergmaier, A. and Vandervorst, W. and Tempel, G. and Maex, K. and Dollinger, G. and Koch, F.},
title = {Electrical activity of B and As segregated at the Si-SiO2 interface},
booktitle = {Silicon Front-End Junction Formation Technologies; San Francisco, CA; United States; 2 -4 April 2002},
publisher = {Materials Research Society},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2002},
volume = {717},
pages = {115--120},
editor = {Downey, D. F. and Law, M. E. and Claverie, A. and Rendon, M. J.},
note = {Silicon Front-End Junction Formation Technologies; San Francisco, CA; United States; 2 April 2002 through 4 April 2002},
url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0036447886&partnerID=40&md5=543aa7a20112572d57821363721ec1fe},
doi = {https://doi.org/10.1557/PROC-717-C3.4}
}
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Ion beam analysis of aluminium in thin layers M. Healy, A. Pidduck, G. Dollinger, L. Görgens and A. Bergmaier; Nuclear Instruments and Methods in Physics Research Section B 190 (1-4) (2002) 630-635. |
| Abstract: This work quantifies aluminium in thin surface and near surface layers. In one example, the layer overlies a thin gallium nitride layer on an aluminium oxide substrate and in a second example the aluminium exists just below the surface of an indium arsenide substrate. The technique of non-Rutherford elastic backscattering of protons was used for the samples where aluminum in the layer of interest needed to be resolved from aluminium in the sapphire substrate and the results were corroborated at the Technische Universität München using heavy ion elastic recoil detection analysis. In the second example, where it was unnecessary to isolate the signal of aluminium in the layer of interest (as the substrate contained no aluminium), then the 27Al(d,p01)28 Al nuclear reaction was used. The elastic proton scattering cross section of aluminum was found to vary very rapidly over the energy range of interest. |
BibTeX:
@article{Healy2002,
author = {Healy, M.J.F. and Pidduck, A.J. and Dollinger, G. and Görgens, L. and Bergmaier, A.},
title = {Ion beam analysis of aluminium in thin layers},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2002},
volume = {190},
number = {1-4},
pages = {630--635},
note = {cited By (since 1996)3},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X01012861},
doi = {https://doi.org/10.1016/S0168-583X(01)01286-1}
}
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Dependence of the doping efficiency on material composition in n-type a-SiOx:H A. Janotta, R. Janssen, M. Schmidt, T. Graf, L. Görgens, C. Hammerl, S. Schreiber, G. Dollinger, A. Bergmaier, B. Stritzker and M. Stutzmann; Journal of Non-Crystalline Solids 299-302 (PART 1) (2002) 579-584. |
| Abstract: Amorphous hydrogenated silicon suboxides (a-SiOx:H) deposited by plasma enhanced chemical vapour deposition (PECVD) have a band gap which can be tuned from 1.9 to 3.0 eV by varying the oxygen content from 0 to 50 at.%. n- and p-type doping is realised by adding PH3 and B2H6, respectively, to the source gases SiH4, H2 and CO2. Alloying with increasing amounts of oxygen reduces the mean co-ordination number 〈r〉 from a value close to 4 (a-Si:H) to approximately 2.7, which gradually approaches the ideal value of 〈r〉=2.4 for network glasses. Thus the incorporation of dopant atoms into electrically active, fourfold co-ordinated sites becomes more unlikely with increasing [O]. As a consequence the conductivity, defect density and doping efficiency in phosphorus doped n-type SiOx undergo drastic changes and show increasingly intrinsic character for higher oxygen concentrations. The dependence of the doping efficiency on average co-ordination 〈r〉 is examined in a quantitative manner. |
BibTeX:
@article{Janotta2002,
author = {Janotta, A. and Janssen, R. and Schmidt, M. and Graf, T. and Görgens, L. and Hammerl, C. and Schreiber, S. and Dollinger, G. and Bergmaier, A. and Stritzker, B. and Stutzmann, M.},
title = {Dependence of the doping efficiency on material composition in n-type a-SiOx:H},
journal = {Journal of Non-Crystalline Solids},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2002},
volume = {299-302},
number = {PART 1},
pages = {579--584},
note = {cited By (since 1996)4},
url = {http://www.sciencedirect.com/science/article/pii/S0022309301009632},
doi = {https://doi.org/10.1016/S0022-3093(01)00963-2}
}
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An ultracold neutron (UCN) detector with Ti/6LiF multi-layer converter and 58Ni reflector P. Maier-Komor, I. Altarev, A. Bergmaier, G. Dollinger, S. Paul, G. Petzoldt and W. Schott; Nuclear Instruments and Methods in Physics Research Section A 480 (1) (2002) 109-113. |
| Abstract: High efficient detectors for ultracold neutrons (UCN) must be developed for the new high flux neutron source Forschungsreaktor München II (FRM II). On silicon PIN diodes 76 μg/cm2 58Ni was deposited as a UCN reflector. On this 100 double layers of natTi (4.7 μg/cm2) and 6LiF (1.8 μg/cm2) were deposited to function as a UCN converter. On top of this, 33 double layers of natTi (3.4 μg/cm2) and 6LiF (0.92 μg/cm2) were condensed in addition to provide sensitivity to very low-energy UCN. Finally, 6.0 μg/cm2 natV was deposited to protect the multi-layers. Vanadium has nearly zero optical potential for UCN and thus should not hinder their transmission. Since no expensive isotopes were involved, a source to substrate distance of 24 cm could be chosen, leading to excellent uniformity. The setup designed for deposition under ultrahigh vacuum conditions and the evaporation procedures are described. |
BibTeX:
@article{Maier-Komor2002,
author = {Maier-Komor, P. and Altarev, I. and Bergmaier, A. and Dollinger, G. and Paul, S. and Petzoldt, G. and Schott, W.},
title = {An ultracold neutron (UCN) detector with Ti/6LiF multi-layer converter and 58Ni reflector},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2002},
volume = {480},
number = {1},
pages = {109--113},
editor = {Ingelbrecht C., Maier-Komor P.},
note = {cited By (since 1996)7},
url = {http://www.sciencedirect.com/science/article/pii/S0168900201020770},
doi = {https://doi.org/10.1016/S0168-9002(01)02077-0}
}
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Development of antireflection coatings with a 6LiF/62Ni multilayer converter for ultracold neutron detectors P. Maier-Komor, I. Altarev, A. Bergmaier, G. Dollinger, S. Paul and W. Schott; Nuclear Instruments and Methods in Physics Research Section A 480 (1) (2002) 104-108. |
| Abstract: High efficiency detectors for ultracold neutrons (UCN) are needed at the new high flux neutron source, Forschungsreaktor München II. In the development described, silicon PIN diodes were chosen to detect the α-particles or the tritons created in the reaction 6Li(n,α)t. The high reflectance of UCN on 6Li with its positive optical potential must be compensated by a material with negative optical potential. The isotope 62Ni was chosen for this. To avoid problems due to chemical reactions of Li with humidity, the compound 6LiF was chosen. One hundred and fifty double layers of 6LiF/62Ni had to be deposited by physical vapor deposition on silicon PIN diodes which had already been coated with 88 nm ≈ 77 μg/cm2 of 58Ni for reflection of the UCN. The theoretical optimal thickness of the 62Ni layers is 3 nm, and that of 6LiF is 6 nm. Since expensive isotopes were involved, a small source-to-substrate distance had to be used, but with the requirement of excellent uniformity. The complicated setup designed for deposition in the 10-6 Pa range and the evaporation procedures are described. |
BibTeX:
@article{Maier-Komor2002a,
author = {Maier-Komor, P. and Altarev, I. and Bergmaier, A. and Dollinger, G. and Paul, S. and Schott, W.},
title = {Development of antireflection coatings with a 6LiF/62Ni multilayer converter for ultracold neutron detectors},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2002},
volume = {480},
number = {1},
pages = {104--108},
editor = {Ingelbrecht C., Maier-Komor P.},
note = {cited By (since 1996)5},
url = {http://www.sciencedirect.com/science/article/pii/S0168900201020769},
doi = {https://doi.org/10.1016/S0168-9002(01)02076-9}
}
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Hydrogen response mechanism of Pt-GaN Schottky diodes J. Schalwig, G. Müller, U. Karrer, M. Eickhoff, O. Ambacher, M. Stutzmann, L. Görgens and G. Dollinger; Applied Physics Letters 80 (7) (2002) 1222-1224. |
| Abstract: Besides silicon carbide, group-III nitrides are also suitable large-band-gap semiconductor materials for high-temperature gas sensor devices. Exposing GaN-based Schottky diodes with catalytically active platinum electrodes to hydrogen, we observed a decrease of the rectifying characteristics which we attribute to a decrease in Schottky barrier height. Current-voltage and elastic recoil detection measurements were used to investigate the H-sensing behavior of such devices. Our results indicate an interfacial effect as the origin of the sensor response to hydrogen. |
BibTeX:
@article{Schalwig2002,
author = {Schalwig, J. and Müller, G. and Karrer, U. and Eickhoff, M. and Ambacher, O. and Stutzmann, M. and Görgens, L. and Dollinger, G.},
title = {Hydrogen response mechanism of Pt-GaN Schottky diodes},
journal = {Applied Physics Letters},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2002},
volume = {80},
number = {7},
pages = {1222-1224},
note = {cited By (since 1996)140},
url = {http://aip.scitation.org/doi/10.1063/1.1450044},
doi = {https://doi.org/10.1063/1.1450044}
}
|
2001 |
|
Deuterium depth profiles at CVD diamond surfaces A. Bergmaier, G. Dollinger, A. Aleksov, P. Gluche and E. Kohn; Surface Science 481 (1-3) (2001) L433-L436. |
| Abstract: Homoepitaxial diamond films grown by chemical vapour deposition (CVD) in a methane deuterium plasma were investigated for their deuterium and hydrogen content using high resolution elastic recoil detection (ERD) with a depth resolution of about 0.5 nm. The as-grown diamond films showed large surface conductivity as it is used for diamond surface channel field effect transistors. The ERD measurements revealed an amount of (1.7±0.2) ×1015 at/cm2 of deuterium on the (100) diamond surface, which is in agreement with a deuterium terminated (2 × 1) reconstructed (100) diamond surface. The hydrogen and deuterium bulk concentration is only about 1.0 × 1019 at/cm3, even at a depth of 1.5 nm below the surface. Therefore, it can be concluded, that the highly conductive p-type layer in as-deposited CVD diamond films is not due to additionally incorporated hydrogen in the subsurface region in contrary to many conduction models. |
BibTeX:
@article{Bergmaier2001,
author = {Bergmaier, A. and Dollinger, G. and Aleksov, A. and Gluche, P. and Kohn, E.},
title = {Deuterium depth profiles at CVD diamond surfaces},
journal = {Surface Science},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2001},
volume = {481},
number = {1-3},
pages = {L433-L436},
note = {cited By (since 1996)14},
url = {http://www.sciencedirect.com/science/article/pii/S0039602801010305},
doi = {https://doi.org/10.1016/S0039-6028(01)01030-5}
}
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High-resolution elastic recoil detection utilizing Bayesian probability theory P. Neumaier, G. Dollinger, A. Bergmaier, I. Genchev, L. Görgens, R. Fischer, C. Ronning and H. Hofsäss; Nuclear Instruments and Methods in Physics Research Section B 183 (1-2) (2001) 48-61. |
| Abstract: Elastic recoil detection (ERD) analysis is improved in view of depth resolution and the reliability of the measured spectra. Good statistics at even low ion fluences is obtained utilizing a large solid angle of 5 msr at the Munich Q3D magnetic spectrograph and using a 40 MeV 197Au beam. In this way the elemental depth profiles are not essentially altered during analysis even if distributions with area densities below 1×1014 atoms/cm2 are measured. As the energy spread due to the angular acceptance is fully eliminated by ion-optical and numerical corrections, an accurate and reliable apparatus function is derived. It allows to deconvolute the measured spectra using the adaptive kernel method, a maximum entropy concept in the framework of Bayesian probability theory. In addition, the uncertainty of the reconstructed spectra is quantified. The concepts are demonstrated at 13C depth profiles measured at ultra-thin films of tetrahedral amorphous carbon (ta-C). Depth scales of those profiles are given with an accuracy of 1.4×1015 atoms/cm2. |
BibTeX:
@article{Neumaier2001,
author = {Neumaier, P. and Dollinger, G. and Bergmaier, A. and Genchev, I. and Görgens, L. and Fischer, R. and Ronning, C. and Hofsäss, H.},
title = {High-resolution elastic recoil detection utilizing Bayesian probability theory},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2001},
volume = {183},
number = {1-2},
pages = {48--61},
note = {cited By (since 1996)17},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X01003470},
doi = {https://doi.org/10.1016/S0168-583X(01)00347-0}
}
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Nitrogen implantations for rapid thermal oxinitride layers A. Stadler, I. Genchev, A. Bergmaier, G. Dollinger, V. Petrova-Koch, W. Mansch, H. Baumgärtner and I. Eisele; Microelectronics and Reliability 41 (7) (2001) 977-980. |
| Abstract: Oxidation of nitrogen implanted substrates results in so called silicon-oxinitride layers (SixOyNz layers) which are dependent on implantation dose and energy always thinner than pure silicon-oxides (SiO2) produced under the same oxidation conditions. Elastic recoil detection profiles indicate that the implanted nitrogen diffuses out of the substrate into the silicon-oxide layer what improves the electrical quality of these insulators. The SixOyNz layers show lower Fowler-Nordheim tunnelling currents as well as lower interface state densities (Dit) than the corresponding SiO2 layers or N2O-silicon-oxinitride insulators. NH3-SixOyNz layers show the lowest Dit values because of H2-annealing effects but contain fixed charges. |
BibTeX:
@article{Stadler2001,
author = {Stadler, A. and Genchev, I. and Bergmaier, A. and Dollinger, G. and Petrova-Koch, V. and Mansch, W. and Baumgärtner, H. and Eisele, I.},
title = {Nitrogen implantations for rapid thermal oxinitride layers},
journal = {Microelectronics and Reliability},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2001},
volume = {41},
number = {7},
pages = {977--980},
note = {cited By (since 1996)5},
url = {http://www.sciencedirect.com/science/article/pii/S0026271401000518},
doi = {https://doi.org/10.1016/S0026-2714(01)00051-8}
}
|
2000 |
|
Quantitative analysis of deuterium in a-C:D layers, a Round Robin experiment R. Behrisch, M. Mayer, W. Jacob, W. Assmann, G. Dollinger, A. Bergmaier, U. Kreissig, M. Friedrich, G. Sun, D. Hildebrandt, M. Akbi, W. Schneider, D. Schleußner, W. Knapp and C. Edelmann; Journal of Nuclear Materials 281 (1) (2000) 42-56. |
| Abstract: The absolute amount of deuterium in amorphous deuterated carbon (a-C:D) layers has been measured by six laboratories with different techniques, such as MeV ion beam analysis, secondary ion mass spectrometry (SIMS), and thermal desorption spectrometry (TDS). The a-C:D layers have been deposited from a CD4 glow discharge plasma onto carbon and silicon substrates. The results for the absolute numbers obtained with the different analyzing techniques show a scatter of up to about 35% around the average value. These deviations are larger than the errors stated by the experimentalists and indicate possible systematic uncertainties in some of the measurements. |
BibTeX:
@article{Behrisch2000,
author = {Behrisch, R. and Mayer, M. and Jacob, W. and Assmann, W. and Dollinger, G. and Bergmaier, A. and Kreissig, U. and Friedrich, M. and Sun, G.Y. and Hildebrandt, D. and Akbi, M. and Schneider, W. and Schleußner, D. and Knapp, W. and Edelmann, C.},
title = {Quantitative analysis of deuterium in a-C:D layers, a Round Robin experiment},
journal = {Journal of Nuclear Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2000},
volume = {281},
number = {1},
pages = {42--56},
note = {cited By (since 1996)15},
url = {http://www.sciencedirect.com/science/article/pii/S0022311500000696},
doi = {https://doi.org/10.1016/S0022-3115(00)00069-6}
}
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Characterization of ultra thin oxynitrides: a general approach B. Brijs, J. Deleu, T. Conard, H. De Witte, W. Vandervorst, K. Nakajima, K. Kimura, I. Genchev, A. Bergmaier, L. Goergens, P. Neumaier, G. Dollinger and M. Döbeli; Nuclear Instruments and Methods in Physics Research Section B 161 (2000) 429-434. |
| Abstract: The determination of nitrogen depth profiles in thin oxynitride layers (1.5-3 nm) becomes more and more important in microelectronics. The goal of this paper is to investigate a methodology for the characterization of thin oxynitride layers with the aim to establish in a quantitative manner the layer thickness, N-content and detailed N-depth profile. For this study ultra thin oxynitride films of 2.5 nm on Si were grown by oxygen O2 annealing of Si followed by a NO annealing. The global film characteristics were measured using spectroscopic ellipsometry (SE) (thickness), atomic force microscopy (AFM) for roughness and X-ray photoelectron spectroscopy (XPS) for total O- and N-content. Depth profiles of oxygen, silicon and nitrogen were obtained using (low energy) secondary ion mass spectroscopy (SIMS) and time of flight (TOF)-SIMS, high resolution-Rutherford backscattering (H-RBS) (magnetic sector and TOF) and high resolution-elastic recoil detection (H-ERD). A comparison of the results obtained with the different techniques is presented and discussed. |
BibTeX:
@article{Brijs2000,
author = {Brijs, B. and Deleu, J. and Conard, T. and De Witte, H. and Vandervorst, W. and Nakajima, K. and Kimura, K. and Genchev, I. and Bergmaier, A. and Goergens, L. and Neumaier, P. and Dollinger, G. and Döbeli, M.},
title = {Characterization of ultra thin oxynitrides: a general approach},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2000},
volume = {161},
pages = {429--434},
note = {cited By (since 1996)20},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X99006746},
doi = {https://doi.org/10.1016/S0168-583X(99)00674-6}
}
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Formation of silicon(111) boron surface phases and their influence on the epitaxial growth of silicon and germanium J. Schulze, H. Baumgärtner, C. Fink, G. Dollinger, I. Gentchev, L. Görgens, W. Hansch, H. Hoster, T. Metzger, R. Paniago, T. Stimpel, T. Sulima and I. Eisele; Thin Solid Films 369 (1) (2000) 10-15. |
| Abstract: We present results obtained by different analysis methods as scanning tunneling microscopy (STM), atomic force microscopy (AFM), grazing incidence small angle X-ray scattering (GISAXS), and elastic recoil detection (ERD) on two similar semiconductor structures grown by molecular beam epitaxy (1) Si(111) substrate/Si buffer layer/B layer with σ B = (2.6±δ)×10 14 cm -2/Ge cap layer and (2) Si(111) substrate/Si buffer layer/B layer with σ B = (2.6±δ)×10 14 cm -2/Si cap layer. It will be shown that the deposition of B with concentrations up to 2.6×10 14 cm -2 leads to a breakdown of the 7×7 reconstructed Si surface of the buffer layer and the formation of a Si(111)-√3×√3-R30 °B surface phase (BSP) located on T 4-sites. Furthermore it is shown that this BSP acts as a `lubricant' for additional deposited adatoms (Si and Ge) at deposition temperatures <800 °C due to the saturation of all Si dangling bonds. This leads to the formation of triangular, nearly relaxed, and well ordered Ge dots in the special case of Ge deposited at 400 °C onto a BSP. For higher deposition temperatures it is shown that this `lubricant effect' vanishes due to the B migration from the T 4-site via S 5 into the substrate. |
BibTeX:
@article{Schulze2000,
author = {Schulze, J. and Baumgärtner, H. and Fink, C. and Dollinger, G. and Gentchev, I. and Görgens, L. and Hansch, W. and Hoster, H.E. and Metzger, T.H. and Paniago, R. and Stimpel, T. and Sulima, T. and Eisele, I.},
title = {Formation of silicon(111) boron surface phases and their influence on the epitaxial growth of silicon and germanium},
journal = {Thin Solid Films},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2000},
volume = {369},
number = {1},
pages = {10--15},
note = {cited By (since 1996)9},
url = {http://www.sciencedirect.com/science/article/pii/S0040609000008257},
doi = {https://doi.org/10.1016/S0040-6090(00)00825-7}
}
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Lithium addition during CVD diamond growth: Influence on the optical emission of the plasma and properties of the films H. Sternschulte, M. Schreck, B. Stritzker, A. Bergmaier and G. Dollinger; Diamond and Related Materials 9 (3) (2000) 1046-1050. |
| Abstract: Lithium-doped homoepitaxial CVD diamond films were grown on synthetic type Ib (100) single crystal diamonds by addition of lithium-t-butoxide (LiOC4H9) to the CH4/H2 microwave plasma. Atomic lithium can easily be detected in the plasma by optical emission spectroscopy (OES). Varying the lithium precursor addition to the gas phase over a wide range, two regimes were found: in the low concentration regime the emission intensity from atomic and molecular hydrogen is independent of the Li concentration, thus facilitating the use of the Li/H emission intensity ratio as a relative measure for the concentration of atomic Li in the plasma; in the high concentration regime the Li addition feeds back on the absolute intensity of the atomic Balmer lines, on the relative intensities of atomic and molecular hydrogen lines and on the activation of different Li transitions. This indicates a modification of the electron energy distribution and also the plasma chemistry. The incorporation of lithium in the deposited homoepitaxial diamond films as studied by elastic recoil detection (ERD) measurements strongly varies with the deposition temperature. It is favoured by low substrate temperatures. A reduction from Tsub = 800 °C to Tsub = 620 °C increases the Li concentration from 8 ppm to 71 ppm. Maximum Li concentrations of 290 ppm were found. The high crystal quality of the films speaks for an incorporation in the crystal lattice and not the grain boundaries. The potential role of other impurities is discussed. |
BibTeX:
@article{Sternschulte2000,
author = {Sternschulte, H. and Schreck, M. and Stritzker, B. and Bergmaier, A. and Dollinger, G.},
title = {Lithium addition during CVD diamond growth: Influence on the optical emission of the plasma and properties of the films},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2000},
volume = {9},
number = {3},
pages = {1046-1050},
note = {cited By (since 1996)20},
url = {http://www.sciencedirect.com/science/article/pii/S0925963599002745},
doi = {https://doi.org/10.1016/S0925-9635(99)00274-5}
}
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Composition, nanostructure and origin of the ultrahardness in nc-TiN/a-Si3N4/a- and nc-TiSi2 nanocomposites with Hv = 80 to ≥105 GPa S. Veprek, A. Niederhofer, K. Moto, T. Bolom, H.-D. Männling, P. Nesladek, G. Dollinger and A. Bergmaier; Surface and Coatings Technology 133-134 (2000) 152-159. |
| Abstract: Multiphase nanocomposite coatings (3-20 μm thick) consisting of nanocrystalline TiN, amorphous Si3N4, and amorphous and nanocrystalline TiSi2, nc-TiN/a-SiNx/a- and nc-TiSi2 were deposited on steel substrates by means of plasma CVD. The load-independent Vickers microhardness from 80 to >105 GPa was measured by the load-depth sensing technique for applied loads between 30 and 200 mN and verified by measuring the size of the remaining plastic indentation using SEM. The results of a complex analysis provide a consistent picture of the nature of the grain boundaries which determines the hardness in the whole range of silicon content between approximately 3 and 22 at.%. At a high discharge current density of ≥2.5 mA/cm2 the a-Si3N4 forms the grain boundaries and the nanocomposites are superhard (40-50 GPa) as we reported earlier. At a lower current density of ≤1 mA/cm2 a mixture of TiSi2 and Si3N4 is formed. With increasing Si-content the amount of a-TiSi2 in the grain boundaries of the TiN nanocrystals increases, and above 10 at.% of Si approximately 3 nm small TiSi2 nanocrystals precipitate. The hardness depends critically and in a complex way on the Si3N4 content and the TiSi2/Si3N4 ratio. The ultrahardness of <&ge;80 GPa is achieved when the surface of the TiN nanocrystals is covered with approximately one monolayer of Si3N4. Under these conditions the ultrahardness of 80-100 GPa depends on the amount of a- and nc-TiSi2. |
BibTeX:
@article{Veprek2000,
author = {Veprek, S. and Niederhofer, A. and Moto, K. and Bolom, T. and Männling, H.-D. and Nesladek, P. and Dollinger, G. and Bergmaier, A.},
title = {Composition, nanostructure and origin of the ultrahardness in nc-TiN/a-Si3N4/a- and nc-TiSi2 nanocomposites with Hv = 80 to ≥105 GPa},
journal = {Surface and Coatings Technology},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2000},
volume = {133-134},
pages = {152--159},
note = {cited By (since 1996)277},
url = {http://www.sciencedirect.com/science/article/pii/S0925963599002745},
doi = {https://doi.org/10.1016/S0257-8972(00)00957-9}
}
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Epitaxial CaGe2 films on germanium G. Vogg, M. Brandt, M. Stutzmann, I. Genchev, A. Bergmaier, L. Görgens and G. Dollinger; Journal of Crystal Growth 212 (1) (2000) 148-154. |
| Abstract: The epitaxial growth of thin CaGe2 films with reactive deposition epitaxy (RDE) on Ge(1 1 1) substrates is described. The films consist in general of a mixture of the known trigonal rhombohedral tr6 modification and a hexagonal h2 modification of CaGe2 containing two Ca and two buckled Ge layers per unit cell in a twofold stacking sequence whose formation appears to be favored by strain. Epitaxial layers of both polytypes show remarkably higher crystalline quality compared to epitaxial CaSi2 films grown on silicon substrates. The tr6 modification is found to be unstable in air in contrast to the h2 modification. |
BibTeX:
@article{Vogg2000,
author = {Vogg, G. and Brandt, M.S. and Stutzmann, M. and Genchev, I. and Bergmaier, A. and Görgens, L. and Dollinger, G.},
title = {Epitaxial CaGe2 films on germanium},
journal = {Journal of Crystal Growth},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {2000},
volume = {212},
number = {1},
pages = {148--154},
note = {cited By (since 1996)7},
url = {http://www.sciencedirect.com/science/article/pii/S0022024800000324},
doi = {https://doi.org/10.1016/S0022-0248(00)00032-4}
}
|
1999 |
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Diamond junction FETs based on δ-doped channels A. Aleksov, A. Vescan, M. Kunze, P. Gluche, W. Ebert, E. Kohn, A. Bergmaier and G. Dollinger; Diamond and Related Materials 8 (2-5) (1999) 941-945. |
| Abstract: Diamond junction field effect transistors (FETs) utilizing δ-boron-doped diamond films were fabricated and analyzed. In order to allow full charge modulation by the gate, the total channel sheet charge must not exceed the order of 1013 cm-2. However, boron doping shows full activation only for concentrations above ca 1020 cm-3 . This yields a thickness for a fully activated channel in the range of ca 1 nm. To approach such narrow doping spikes any parasitic boron doping tails need to be eliminated. One possible way of achieving this is to compensate boron doping with nitrogen doping, an extremely deep donor. This results in the formation of a pn-junction, where the nitrogen doped part is not activated at room temperature and which therefore represents a semi-insulating (lossy) dielectric at low temperature and high frequency. At elevated temperature and low frequency the nitrogen doped layer becomes conducting acting as a series resistor to the interfacial pn-junction. Using this concept of a lossy dielectric pn-junction in the δ-doped channel FET, two gate diode configurations were investigated. In the first the nitrogen doped (Ib) synthetic diamond substrate served as a large area back gate, while in the second the nitrogen doped gate layer was grown on top of the δ-channel. The devices show high drain currents of up to 100 mA mm-1 and full channel modulation even at moderate operation temperatures of 200-250 °C. By extrapolation a current density of 1 A mm-1 is expected for a 0.25 μm gate length device. |
BibTeX:
@article{Aleksov1999,
author = {Aleksov, A. and Vescan, A. and Kunze, M. and Gluche, P. and Ebert, W. and Kohn, E. and Bergmaier, A. and Dollinger, G.},
title = {Diamond junction FETs based on δ-doped channels},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
volume = {8},
number = {2-5},
pages = {941--945},
note = {cited By (since 1996)45},
url = {http://www.sciencedirect.com/science/article/pii/S0925963598003938},
doi = {https://doi.org/10.1016/S0925-9635(98)00393-8}
}
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Oxygen at the interface of CVD diamond films on silicon A. Bergmaier, M. Schreck, G. Dollinger, O. Schmelmer, K. Thürer and B. Stritzker; Diamond and Related Materials 8 (6) (1999) 1142-1147. |
| Abstract: The oxygen incorporation at the interface between the silicon substrate and chemical vapour deposited (CVD) diamond films nucleated by the bias-enhanced nucleation (BEN) procedure has been studied by heavy-ion elastic recoil detection (ERD). Using standard process conditions for the realisation of heteroepitaxial films, oxygen with a concentration equivalent to about 1nm SiO2 has been found, which was mainly incorporated during textured growth with a certain CO2 admixture to the process gas. By completely omitting CO2 during nucleation and growth, the oxygen at the interface can be reduced by nearly one order of magnitude to 6.3×1015atcm-2, corresponding to 0.14nm SiO2. Intentional addition of highly enriched C18O2 to the gas phase shows that the oxygen incorporation is strongly enhanced during BEN with hydrocarbon in the gas phase. The results indicate that roughening of the surface, the deposition of SixOyCz phases and strong lateral inhomogeneities at the silicon interface may explain the coexistence of epitaxial crystallites and amorphous phases. It is suggested that a further reduction of the oxygen concentration at the interface may have consequences for an improved heteroepitaxy of diamond on silicon. |
BibTeX:
@article{Bergmaier1999,
author = {Bergmaier, A. and Schreck, M. and Dollinger, G. and Schmelmer, O. and Thürer, K.H. and Stritzker, B.},
title = {Oxygen at the interface of CVD diamond films on silicon},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
volume = {8},
number = {6},
pages = {1142-1147},
note = {cited By (since 1996)6},
url = {http://www.sciencedirect.com/science/article/pii/S0925963599001041},
doi = {https://doi.org/10.1016/S0925-9635(99)00104-1}
}
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Composition analysis using elastic recoil detection L. Görgens, G. Dollinger, A. Bergmaier, O. Ambacher, L. Eastman, J. Smart, J. Shealy, R. Dimitrov, M. Stutzmann and A. Mitchell; Physica Status Solidi (B) Basic Research 216 (1) (1999) 679-682. |
| Abstract: We report quantitative ERD (Elastic Recoil Detection) measurements for the determination of the composition and distribution of the elements in nitride heterostructures. The investigated samples were MOCVD (molecular chemical vapor deposition) and PIMBE (plasma induced molecular beam epitaxy) grown HEMT (high electron mobility transistor) structures from Cornell University. We present the measured Al distribution parallel to the growth direction of Al xGa 1 xN layers of a thickness of about 10 to 30 nm and an Al concentration of x = 0.1 to 0.7. The results are compared with HRXRD (high resolution X-ray diffraction) measurements. |
BibTeX:
@article{Goergens1999,
author = {Görgens, L. and Dollinger, G. and Bergmaier, A. and Ambacher, O. and Eastman, L. and Smart, J.A. and Shealy, J.F. and Dimitrov, R. and Stutzmann, M. and Mitchell, A.},
title = {Composition analysis using elastic recoil detection},
journal = {Physica Status Solidi (B) Basic Research},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
volume = {216},
number = {1},
pages = {679--682},
note = {cited By (since 1996)0},
url = {http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1521-3951(199911)216:1%3C679::AID-PSSB679%3E3.0.CO;2-L/abstract},
doi = {https://doi.org/10.1002/(SICI)1521-3951(199911)216:1%3C679::AID-PSSB679%3E3.0.CO;2-L}
}
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δ-doping in diamond M. Kunze, A. Vescan, G. Dollinger, A. Bergmaier and E. Kohn; Carbon 37 (5) (1999) 787-791. |
| Abstract: δ-Boron-doped homoepitaxial diamond films grown by microwave CVD were optimized for field effect transistor application to obtain steep profiles. The critical growth steps of the δ-doped device structures were analyzed and improved using mass spectrometry gas analysis, determining growth- and etch rates, hall-effect-measurements, elastic recoil detection and conductivity measurements. Optimized growth procedures were obtained and residual doping in the gate control layer was compensated using nitrogen. This results in a novel lossy dielectric Junction FET channel with high sheet charge activation and high drain current densities at moderate operation temperatures of 200 °C. |
BibTeX:
@article{Kunze1999,
author = {Kunze, M. and Vescan, A. and Dollinger, G. and Bergmaier, A. and Kohn, E.},
title = {δ-doping in diamond},
journal = {Carbon},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
volume = {37},
number = {5},
pages = {787--791},
note = {cited By (since 1996)31},
url = {http://www.sciencedirect.com/science/article/pii/S0008622398002723},
doi = {https://doi.org/10.1016/S0008-6223(98)00272-3}
}
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Reproducibility and simplification of the preparation procedure for carbon stripper foils by laser plasma ablation deposition P. Maier-Komor, G. Dollinger and H. Körner; Nuclear Instruments and Methods in Physics Research Section A 438 (1) (1999) 73-78. |
| Abstract: Carbon stripper foils prepared by laser plasma ablation deposition are so far the only ones which have a total random orientation of the nanocrystallites. This orientation is responsible for the long lifetimes under heavy ion bombardment. Accelerator users around the world are interested in this type of carbon stripper foils. Their strong interest is a guaranteed reproducibility of the foil quality, -thickness and -uniformity. In addition, a high reproducible yield with a low effort for floating, mounting and slackening is wanted. These problems are discussed and the status of their solution is described. |
BibTeX:
@article{Maier-Komor1999,
author = {Maier-Komor, P. and Dollinger, G. and Körner, H.J.},
title = {Reproducibility and simplification of the preparation procedure for carbon stripper foils by laser plasma ablation deposition},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
volume = {438},
number = {1},
pages = {73--78},
note = {cited By (since 1996)19},
url = {http://www.sciencedirect.com/science/article/pii/S0168900299009419},
doi = {https://doi.org/10.1016/S0168-9002(99)00941-9}
}
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Boron in mesoporous Si - where have all the carriers gone? G. Polisski, D. Kovalev, G. Dollinger, T. Sulima and F. Koch; Physica B: Condensed Matter 273-274 (1999) 951-954. |
| Abstract: Highly-doped p-type Si is electrochemically etched in an HF-based electrolyte to produce mesoporous surface layers. Using both elastic-recoil detection analysis and secondary ion mass spectroscopy it is concluded that B atoms are not removed from the porous layer. Crystallite size for the most porous samples is related to the average dopant spacing. It is argued that the electrolytic erosion of Si stops when B is in the surface layer and passivated. |
BibTeX:
@article{Polisski1999,
author = {Polisski, G. and Kovalev, D. and Dollinger, G. and Sulima, T. and Koch, F.},
title = {Boron in mesoporous Si - where have all the carriers gone?},
journal = {Physica B: Condensed Matter},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
volume = {273-274},
pages = {951--954},
note = {cited By (since 1996)39},
url = {http://www.sciencedirect.com/science/article/pii/S0921452699005621},
doi = {https://doi.org/10.1016/S0921-4526(99)00562-1}
}
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Control of lithium-t-butoxide addition during chemical vapour deposition of Li-doped diamond films by optical emission spectroscopy H. Sternschulte, M. Schreck, B. Stritzker, A. Bergmaier and G. Dollinger; Physica Status Solidi (A) Applied Research 174 (1) (1999) 65-72. |
| Abstract: The potential of in situ lithium doping of diamond during microwave plasma chemical vapour deposition (MWPCVD) using a source of solid lithium-t-butoxide has been studied. It is shown that atomic lithium emission lines can be easily detected in the plasma by optical emission spectroscopy (OES). It was found that for a fixed fraction of the Li precursor in the feed gas a variation of the experimental conditions in the CVD reactor can drastically change the Li concentration in the plasma. The experimental results demonstrate that an optical control of the Li concentration in the plasma is indispensible. Elastic recoil detection (ERD) measurements clearly established that Li was incorporated into the diamond films in concentrations ranging from 40 up to 300 ppm. Etching of plasma exposed steel components in the reactor due to Li addition and the subsequent incorporation of iron, cobalt, and nickel into the films could be strongly reduced by replacing these components by graphite parts. |
BibTeX:
@article{Sternschulte1999,
author = {Sternschulte, H. and Schreck, M. and Stritzker, B. and Bergmaier, A. and Dollinger, G.},
title = {Control of lithium-t-butoxide addition during chemical vapour deposition of Li-doped diamond films by optical emission spectroscopy},
journal = {Physica Status Solidi (A) Applied Research},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
volume = {174},
number = {1},
pages = {65--72},
note = {cited By (since 1996)9},
url = {http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1521-396X(199907)174:1%3C65::AID-PSSA65%3E3.0.CO;2-W/abstract},
doi = {https://doi.org/10.1002/(SICI)1521-396X(199907)174:1%3C65::AID-PSSA65%3E3.0.CO;2-W}
}
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The effect of nitrogen on low temperature growth of diamond films J. Stiegler, A. Bergmaier, J. Michler, S. Laufer, G. Dollinger and E. Blank; Thin Solid Films 352 (1-2) (1999) 29-40. |
| Abstract: The intentional addition of small amounts of nitrogen to different C/H/O gas systems in microwave plasma-assisted deposition of diamond films at low substrate temperatures has been studied. The effect on growth is qualitatively different for gas mixtures with or without oxygen. Adding nitrogen to C/H mixtures results in a significant change of film morphology, growth rate, defect formation and incorporation of hydrogen. The film quality seriously deteriorates with increasing nitrogen concentration in the gas phase. The influence of nitrogen on gas phase processes has been monitored by optical emission spectroscopy. There is evidence that nitrogen affects growth primarily by surface related mechanisms. By contrast, its effect on growth from CO-rich C/H/O systems is much less pronounced. These films show a constant quality and a lower defect content. The interaction of nitrogen and oxygen in low temperature growth of diamond films has been thoroughly examined for gas mixtures containing comparatively low oxygen fractions. The presence of oxygen effectively counteracts the deleterious effect of nitrogen on the formation of defects. Elastic recoil detection has shown, however, that the incorporation of nitrogen into the film always increases when its gas phase concentration is raised, no matter which gas system is chosen. |
BibTeX:
@article{Stiegler1999,
author = {Stiegler, J. and Bergmaier, A. and Michler, J. and Laufer, S. and Dollinger, G. and Blank, E.},
title = {The effect of nitrogen on low temperature growth of diamond films},
journal = {Thin Solid Films},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
volume = {352},
number = {1-2},
pages = {29--40},
note = {cited By (since 1996)25},
url = {http://www.sciencedirect.com/science/article/pii/S0040609099002850},
doi = {https://doi.org/10.1016/S0040-6090(99)00285-0}
}
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High pressure fabrication and processing of GaN:Mg T. Suski, J. Jun, M. Leszczynski, H. Teisseyre, I. Grzegory, S. Porowski, G. Dollinger, K. Saarinen, T. Laine, J. Nissilä, W. Burkhard, W. Kriegseis and B. Meyer; Materials Science and Engineering B: Solid-State Materials for Advanced Technology 59 (1-3) (1999) 1-5. |
| Abstract: Results on introduction of magnesium to GaN by three methods are presented. They consists of (i) high pressure growth of bulk, single crystals of GaN from Ga + Mg melt, (ii) diffusion of Mg to bulk GaN and to layers of GaN/Al2O3 at high temperatures and high pressures and (iii) implantation of Mg to bulk, single crystals and to layers of GaN/Al2O3 and subsequent high-pressure annealing. Applied pressure is in the range of 10-15 kbar and temperatures between 1200-1500°C. The growth of bulk, highly Mg doped crystals leads to the semi-insulating material with the characteristic blue photoluminescence band at about 3 eV. High pressure annealing of bulk crystals as well as GaN/Al2O3 layers in (N2 + Mg) atmosphere leads to the increase in the Mg incorporation with the highest diffusivity observed for GaN/Al2O3 layers. The performed experiments give an evidence of the importance of the defect (dislocations) in diffusion of Mg in the GaN semiconductor. Moreover, incorporation of Mg impurity appears to be higher on (00.1) Ga-face of the wurtzite GaN crystals than on the (00. - 1) N-face. We demonstrate also a strong enhancement of the blue-photoluminescence intensity in high pressure annealed GaN/Al2O3 layers (N2 + Mg atmosphere) and Mg-implanted and high pressure annealed GaN crystals and layers. |
BibTeX:
@article{Suski1999,
author = {Suski, T. and Jun, J. and Leszczynski, M. and Teisseyre, H. and Grzegory, I. and Porowski, S. and Dollinger, G. and Saarinen, K. and Laine, T. and Nissilä, J. and Burkhard, W. and Kriegseis, W. and Meyer, B.K.},
title = {High pressure fabrication and processing of GaN:Mg},
journal = {Materials Science and Engineering B: Solid-State Materials for Advanced Technology},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
volume = {59},
number = {1-3},
pages = {1--5},
note = {cited By (since 1996)7},
url = {http://www.sciencedirect.com/science/article/pii/S0921510798004024},
doi = {https://doi.org/10.1016/S0921-5107(98)00402-4}
}
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Optical And Electronic Structure Studies Of Gallium Nitride Single Crystals T. Suski, H. Teisseyre, I. Grzegory, S. Porowski, O. Ambacher, L. Wittmer, T. Wethkamp and G. Dollinger; In: , D. Gershoni (Ed.), Proceedings of the 24th International Conference on the Physics of Semiconductors (1999) , World Scientific, New Jersey. |
BibTeX:
@inproceedings{Suski1999a,
author = {Suski, T. and Teisseyre, H. and Grzegory, I. and Porowski, S. and Ambacher, O. and Wittmer, L. and Wethkamp, T. and Dollinger, G.},
title = {Optical And Electronic Structure Studies Of Gallium Nitride Single Crystals},
booktitle = {Proceedings of the 24th International Conference on the Physics of Semiconductors},
publisher = {World Scientific, New Jersey},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1999},
editor = {David Gershoni},
note = {ISBN: 978-981-02-3613-7},
url = {http://www.worldscientific.com/worldscibooks/10.1142/3915}
}
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1998 |
|
A compact ΔE-Eres detector for elastic recoil detection with high sensitivity A. Bergmaier, G. Dollinger and C. Frey; Nuclear Instruments and Methods in Physics Research Section B 136-138 (1998) 638-643. |
| Abstract: A new compact ΔE-Eres detector telescope has been installed in the scattering chamber of the Munich Q3D magnetic spectrograph in order to increase the sensitivity and depth resolution in classical elastic recoil detection (ERD) measurements. It consists of a two dimensional position sensitive ionisation chamber for energy loss and a position sensitive silicon PIN diode for residual energy measurements. A large solid angle of detection of about 4.5 msr combined with good angular resolution in x and y directions enables high sensitivity ERD depth profiling with a sensitivity in the ppm range and a depth resolution of about 10 nm. |
BibTeX:
@article{Bergmaier1998,
author = {Bergmaier, A. and Dollinger, G. and Frey, C.M.},
title = {A compact ΔE-Eres detector for elastic recoil detection with high sensitivity},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {136-138},
pages = {638--643},
note = {cited By (since 1996)32},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X9700877X},
doi = {https://doi.org/10.1016/S0168-583X(97)00877-X}
}
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Nonequilibrium charge states of recoil ions in high resolution elastic recoil detection analysis G. Dollinger, M. Boulouednine, A. Bergmaier and T. Faestermann; Nuclear Instruments and Methods in Physics Research Section B 136-138 (1998) 574-578. |
| Abstract: The measured profiles of a high resolution elastic recoil detection (ERD) analysis utilizing electrostatic or magnetic spectrographs may contain artefacts if only one charge state is measured. This effect is demonstrated by the analysis of 31.8 MeV 12Cq+ recoil ions of different charge states q+ scattered from a pure graphite sample using 60 MeV 58Ni8+ ions at a scattering angle of 15° and by the analysis of a thin BN film. The primary charge state distribution obtained from scattering events very near the surface significantly deviates from the equilibrium one which is measured for carbon ions scattered deeper than 1017 at/cm2 below the surface. Charge exchange cross sections between the main charge states are obtained analysing the depth dependent charge state distributions. |
BibTeX:
@article{Dollinger1998,
author = {Dollinger, G. and Boulouednine, M. and Bergmaier, A. and Faestermann, T.},
title = {Nonequilibrium charge states of recoil ions in high resolution elastic recoil detection analysis},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {136-138},
pages = {574--578},
note = {cited By (since 1996)7},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X97006629?via%3Dihub},
doi = {https://doi.org/10.1016/S0168-583X(97)00662-9}
}
|
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Depth profile analysis with monolayer resolution using elastic recoil detection (ERD) G. Dollinger, C. Frey, A. Bergmaier and T. Faestermann; Europhysics Letters 42 (1) (1998) 25-30. |
| Abstract: The conditions for obtaining optimum depth resolution in elastic recoil detection (ERD) analysis of thin films using high-energy heavy ions are investigated. We estimate the principle limits given by energy straggling and small-angle scattering effects and show that monolayer depth resolution can be expected under optimized experimental conditions. Such a resolution is demonstrated in an ERD experiment for the first time by discrete signals of adjacent (002) graphite layers which is obtained using a 60 MeV 127I 23+ ion beam and detecting 12C 5+ recoils with a magnetic spectrograph. |
BibTeX:
@article{Dollinger1998a,
author = {Dollinger, G. and Frey, C.M. and Bergmaier, A. and Faestermann, T.},
title = {Depth profile analysis with monolayer resolution using elastic recoil detection (ERD)},
journal = {Europhysics Letters},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {42},
number = {1},
pages = {25--30},
note = {cited By (since 1996)23},
url = {http://iopscience.iop.org/article/10.1209/epl/i1998-00547-6/meta},
doi = {https://doi.org/10.1209/epl/i1998-00547-6}
}
|
|
Elastic recoil detection with single atomic layer depth resolution G. Dollinger, C. Frey, A. Bergmaier and T. Faestermann; Nuclear Instruments and Methods in Physics Research Section B 136-138 (1998) 603-610. |
| Abstract: The necessary conditions for single atomic layer depth resolution in Elastic Recoil Detection (ERD) analysis will be summarized in this paper: First there are rigorous requirements for the ion beam conditions and for the energy resolution of the recoil ion detector in order to obtain an energy resolution in the order of 5 × 10 -4. Second, the most limiting factors in depth resolution are due to the physical limits imposed by small angle scattering effects and due to the energy loss spread of the incident and recoil ions. Last but not least, the third point deals with irradiation damage which has to be carefully controlled in order to measure the original depth profile before it is altered by the ion beam. As studied by energy loss measurements in transmission geometry through thin carbon foils the energy spread of heavy ions strongly depends on the charge state of the incident ions. In order to obtain the smallest energy spread the data show that the charge state of the incident ions should be near equilibrium. Using a 60 MeV 127I 23+ ion beam the resolution of single atomic carbon layers of a highly oriented pyrolythic graphite (HOPG) sample could be demonstrated analysing the 12C 5+ recoils with the Munich Q3D magnetic spectrograph. As far as we know it is the first time that separated signals of neighbouring atomic layers could be resolved using ERD. |
BibTeX:
@article{Dollinger1998b,
author = {Dollinger, G. and Frey, C.M. and Bergmaier, A. and Faestermann, T.},
title = {Elastic recoil detection with single atomic layer depth resolution},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {136-138},
pages = {603--610},
note = {cited By (since 1996)27},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X97008732?via%3Dihub},
doi = {https://doi.org/10.1016/S0168-583X(97)00873-2}
}
|
|
Monolayers of graphite resolved by elastic recoil detection G. Dollinger, C.M. Frey, A. Bergmaier and T. Faestermann; Europhysics Letters 42 (1998) 25. |
BibTeX:
@article{Dollinger1998c,
author = {Dollinger, G. and Frey, C. M. and Bergmaier, A. and Faestermann, T.},
title = {Monolayers of graphite resolved by elastic recoil detection},
journal = {Europhysics Letters},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {42},
pages = {25},
url = {http://iopscience.iop.org/article/10.1209/epl/i1998-00547-6/meta},
doi = {https://doi.org/10.1209/epl/i1998-00547-6}
}
|
|
High resolution depth profiling of light elements in silicon nanostructures utilizing elastic recoil detection (ERD) G. Dollinger, V. Petrova-Koch and I. Eisele; In: Proceedings of Nano-El 98 (?) A4-1 (1998) . |
BibTeX:
@inproceedings{Dollinger1998d,
author = {Dollinger, G. and V. Petrova-Koch and Eisele, I.},
title = {High resolution depth profiling of light elements in silicon nanostructures utilizing elastic recoil detection (ERD)},
booktitle = {Proceedings of Nano-El 98 (?)},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {A4-1}
}
|
|
Bias enhanced nucleation and growth of diamond films on titanium substrates R. Fehling, M. Schreck, A. Bergmaier, G. Dollinger and B. Stritzker; Materials Science Forum 287-288 (1998) 315-318. |
| Abstract: Diamond films have been deposited on titanium substrates by microwave plasma chemical vapour deposition using the bias enhanced nucleation procedure. In the first minutes of exposure to the plasma there is a strong roughening of the titanium surface and a reduction of the oxide layer. Interaction with the gas phase as well as dissolution of the oxygen in the bulk contribute to this reduction. After 30 min plasma treatment the oxygen concentration in the bulk is reduced down to 0.2-0.3% and an accelerated hydrogen dissolution, hydride formation and carburization follow. Analogously to silicon the nucleation density increases with biasing time accompanied by a rise in the biasing current. Surpassing an optimum duration of the biasing process deposition of graphitic carbon is enhanced. The nucleation layer determines the bonding at the interface even after a long diamond growth process resulting in a bad adhesion of the films for long biasing procedures. |
BibTeX:
@article{Fehling1998,
author = {Fehling, R. and Schreck, M. and Bergmaier, A. and Dollinger, G. and Stritzker, B.},
title = {Bias enhanced nucleation and growth of diamond films on titanium substrates},
journal = {Materials Science Forum},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {287-288},
pages = {315--318},
note = {cited By (since 1996)0},
url = {https://www.scientific.net/MSF.287-288.315},
doi = {https://doi.org/10.4028/www.scientific.net/MSF.287-288.315}
}
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The nucleation and growth of large area, highly oriented diamond films on silicon substrates A. Flöter, H. Güttler, G. Schulz, D. Steinbach, C. Lutz-Elsner, R. Zachai, A. Bergmaier and G. Dollinger; Diamond and Related Materials 7 (2-5) (1998) 283-288. |
| Abstract: Highly oriented diamond films can play an important role in replacing single crystal diamond for their use as substrates in active electronic devices. However, for practical applications, large, homogenous films with low defect densities are required. The focus of our investigations is the nucleation of highly oriented diamond on (001) silicon via Bias Enhanced Nucleation (BEN) over large areas. A modified BEN process using repetitive pulse bias 'RP-BEN' was developed, resulting in an area of oriented nucleation of up to 30 cm2. The density of azimuthally oriented diamond seeds was measured by scanning electron microscopy (SEM) images and found to be 8 × 108 cm-2 with only 30% variation over the whole deposition area. After the nucleation, a microwave plasma assisted chemical vapor deposition (MPACVD) resulted in highly oriented and 〈100〉 textured diamond films. X-ray diffraction (XRD) measurements of the 111 diamond peak, for a 60-μm-thick film, showed azimuthally misorientations (FWHM) of 2.8° for the tilt and 5.5° for the rotation. Raman spectroscopy was used to evaluate the radial distribution of the phase purity within the films. Introducing a final growth step with a low nitrogen concentration in the gas phase yielded a significant decrease in nitrogen incorporation in the films while maintaining the morphology. Elastic recoil detection (ERD) revealed impurity concentrations in the surface layer of 1.4 ppm for the N/C ratio and 210 ppm for the H/C ratio. |
BibTeX:
@article{Floeter1998,
author = {Flöter, A. and Güttler, H. and Schulz, G. and Steinbach, D. and Lutz-Elsner, C. and Zachai, R. and Bergmaier, A. and Dollinger, G.},
title = {The nucleation and growth of large area, highly oriented diamond films on silicon substrates},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {7},
number = {2-5},
pages = {283--288},
note = {cited By (since 1996)36},
url = {http://www.sciencedirect.com/science/article/pii/S0925963597002458?via%3Dihub},
doi = {https://doi.org/10.1016/S0925-9635(97)00245-8}
}
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Gradient interface layers to improve c-BN thin film adhesion R. Freudenstein, S. Reinke, W. Kulisch, R. Fischer, J. Zweck, A. Bergmaier and G. Dollinger; Materials Science Forum 287-288 (1998) 259-262. |
| Abstract: The poor adhesion commonly observed for c-BN thin films is caused by the high compressive stress of the films, and the low adhesion strength at the interface. A close examination of the special nature of the c-BN/substrate interface shows that the textured h-BN nucleation layer is mechanically the weakest link of the system and should thus be avoided. Further measures to increase the adhesion strength are a rough interface, and interfacial adhesion layers. First experiments to deposit a graded interface layer (B → BN) result in extremly rough interfaces, a reduced nucleation layer thickness, and a drastically improved adhesion. |
BibTeX:
@article{Freudenstein1998,
author = {Freudenstein, R. and Reinke, S. and Kulisch, W. and Fischer, R. and Zweck, J. and Bergmaier, A. and Dollinger, G.},
title = {Gradient interface layers to improve c-BN thin film adhesion},
journal = {Materials Science Forum},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {287-288},
pages = {259--262},
note = {cited By (since 1996)12},
url = {https://www.scientific.net/MSF.287-288.259},
doi = {https://doi.org/10.4028/www.scientific.net/MSF.287-288.259}
}
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Diamond growth with boron addition P. Hartmann, S. Bohr, R. Haubner, B. Lux, P. Wurzinger, M. Griesser, A. Bergmaier, G. Dollinger, H. Sternschulte and R. Sauer; International Journal of Refractory Metals and Hard Materials 16 (3) (1998) 223-232. |
| Abstract: Diamond coatings were produced on Si substrates by the hot-filament method, with B(C 2H 5) 3 added to the gas phase. Ratios of B(C 2H 5) 3: CH 4 up to 0.01 (10000 ppm) were used which gave boron concentrations up to 3% in the layer according to secondary ion mass spectrometry (SIMS) and elastic recoil detection (ERD) measurements. The characteristic Raman peak of diamond at 1332 cm -1 decreases with increasing boron incorporation. Studying this effect in detail shows that on (100) facets the Raman peak still can be observed while on (111) it is already severely deteriorated. TEM and localized EELS spectra show high boron incorporation in the (111) growth sectors and low boron concentration in the (100) sectors. With cathodoluminescence spectroscopy measurements electronic properties were determined. The Mott-transition from semiconductor to metal-like conduction was found to occur at 0.11% B, which is in agreement with published Hall-measurements. |
BibTeX:
@article{Hartmann1998,
author = {Hartmann, P. and Bohr, S. and Haubner, R. and Lux, B. and Wurzinger, P. and Griesser, M. and Bergmaier, A. and Dollinger, G. and Sternschulte, H. and Sauer, R.},
title = {Diamond growth with boron addition},
journal = {International Journal of Refractory Metals and Hard Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {16},
number = {3},
pages = {223--232},
note = {cited By (since 1996)11},
url = {http://www.sciencedirect.com/science/article/pii/S0263436898000225?via%3Dihub},
doi = {https://doi.org/10.1016/S0263-4368(98)00022-5}
}
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Acceptor depletion in p-type porous silicon G. Polisski, G. Dollinger, A. Bergmaier, D. Kovalev, H. Heckler and F. Koch; Physica Status Solidi (A) Applied Research 168 (1) (1998) R1-R2. |
BibTeX:
@article{Polisski1998,
author = {Polisski, G. and Dollinger, G. and Bergmaier, A. and Kovalev, D. and Heckler, H. and Koch, F.},
title = {Acceptor depletion in p-type porous silicon},
journal = {Physica Status Solidi (A) Applied Research},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {168},
number = {1},
pages = {R1-R2},
note = {cited By (since 1996)9},
url = {http://onlinelibrary.wiley.com/doi/10.1002/(SICI)1521-396X(199807)168:1%3CR1::AID-PSSA99991%3E3.0.CO;2-4/abstract},
doi = {https://doi.org/10.1002/(SICI)1521-396X(199807)168:1%3CR1::AID-PSSA99991%3E3.0.CO;2-4}
}
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Excited state population effect of 60 MeV 58Ni18+ ions penetrating thin carbon foils O. Schmelmer, G. Dollinger, C. Frey, A. Bergmaier and S. Karsch; Nuclear Instruments and Methods in Physics Research Section B 142 (1-2) (1998) 210-213. |
| Abstract: Measurements of the charge fractions F(q) of 60 MeV 58Ni18+ traversing thin carbon foils in dependence on their thickness show a non-trivial behavior. Particularly, the charge fraction of the analysed charge state 18+ has a minimum for foil thickness below 1.9 μg/cm2. This behavior can be interpreted by fast electron capture into high shells and a slow depopulation and excitation of innershells. |
BibTeX:
@article{Schmelmer1998,
author = {Schmelmer, O. and Dollinger, G. and Frey, C.M. and Bergmaier, A. and Karsch, S.},
title = {Excited state population effect of 60 MeV 58Ni18+ ions penetrating thin carbon foils},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {142},
number = {1-2},
pages = {210--213},
note = {cited By (since 1996)2},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X98002730},
doi = {https://doi.org/10.1016/S0168-583X(98)00273-0}
}
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Energy straggling of 60 MeV 58Niq+ ions in thin carbon foils and gases O. Schmelmer, G. Dollinger, C. Frey, A. Bergmaier and S. Karsch; Nuclear Instruments and Methods in Physics Research Section B 145 (3) (1998) 261-270. |
| Abstract: Energy straggling of 60 MeV 58Niq+ ions in thin carbon foils and gas layers has been measured with a Q3D magnetic spectrograph in dependence of the incident and analysed charge state of the ions. The straggling increases with the number of electrons per gas molecule, thus showing strong correlation effects. In solid carbon, however, energy straggling is close to the data of deuterium gas. The small straggling in carbon is interpreted as an effect of the long range interaction of the heavy ions in dense solids. Furthermore, it is observed that energy straggling depends on the charge state of the projectiles unless the equilibrium charge state is reached. |
BibTeX:
@article{Schmelmer1998a,
author = {Schmelmer, O. and Dollinger, G. and Frey, C.M. and Bergmaier, A. and Karsch, S.},
title = {Energy straggling of 60 MeV 58Niq+ ions in thin carbon foils and gases},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {145},
number = {3},
pages = {261--270},
note = {cited By (since 1996)8},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X98005266},
doi = {https://doi.org/10.1016/S0168-583X(98)00526-6}
}
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Charge dependent energy loss of 60 MeV 58Niq+ ions in argon gas O. Schmelmer, G. Dollinger, C. Frey, A. Bergmaier and S. Karsch; Nuclear Instruments and Methods in Physics Research Section B 146 (1-4) (1998) 95-100. |
| Abstract: Energy loss and charge fractions of 60 MeV 58Niq+ ions in argon gas (0.1-16 μg/cm2) have been measured by means of a Q3D magnetic spectrograph in dependence of the incident and analysed charge state of the ions. The measurements show energy loss phenomena at argon gas thicknesses where the charge state distribution is not in equilibrium. For the charge state q = 8+ the stopping power at small target thickness deviates significantly from the value at larger gas thickness. The stopping power of q = 18+ is almost the same as for q = 14+ but energy loss shows a step at about 2 μg/cm2. The deviation of the stopping power at small gas thickness is a combination of two effects. The evolution of the ion's mean charge with increasing target thickness and a selection of impact parameter in collisions between projectiles and gas atoms. |
BibTeX:
@article{Schmelmer1998b,
author = {Schmelmer, O. and Dollinger, G. and Frey, C.M. and Bergmaier, A. and Karsch, S.},
title = {Charge dependent energy loss of 60 MeV 58Niq+ ions in argon gas},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {146},
number = {1-4},
pages = {95--100},
note = {cited By (since 1996)6},
url = {http://www.sciencedirect.com/science/article/pii/S0168583X98904840},
doi = {https://doi.org/10.1016/S0168-583X(98)90484-0}
}
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Modification of diamond film growth by a negative bias voltage in microwave plasma chemical vapor deposition M. Schreck, T. Baur, R. Fehling, M. Müller, B. Stritzker, A. Bergmaier and G. Dollinger; Diamond and Related Materials 7 (2-5) (1998) 293-298. |
| Abstract: Diamond growth by microwave plasma chemical vapor deposition (MPCVD) under the influence of an additional negative bias voltage has been studied. From the in-situ measurement of the growth rate and the curvature of the silicon substrate, the intrinsic film stress was monitored during the deposition for bias voltages ranging from 0 to -200 V and for different process pressures. The mass density of the films, their structural properties and the incorporation of hydrogen and nitrogen impurities from the gas phase were determined ex-situ by Rutherford backscattering, Raman spectroscopy and elastic recoil detection, respectively. For the growth under bias, two regimes have been distinguished. At 50 mbar, the intrinsic stress is tensile between Ubias=0V and -100 V, and the growth is only weakly disturbed by the biasing conditions. At -100 V the macroscopic intrinsic stress vanishes. In the second regime, compressive stress rises rapidly and saturates at -3 GPa. Furthermore, the carbon deposition rate increases by a factor of four, accompanied by an increased incorporation of hydrogen and nitrogen and a deterioration of the crystalline quality of the films. The results are discussed in terms of a modification of the film growth by the additional flux of hyperthermal gas species. |
BibTeX:
@article{Schreck1998,
author = {Schreck, M. and Baur, T. and Fehling, R. and Müller, M. and Stritzker, B. and Bergmaier, A. and Dollinger, G.},
title = {Modification of diamond film growth by a negative bias voltage in microwave plasma chemical vapor deposition},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {7},
number = {2-5},
pages = {293--298},
note = {cited By (since 1996)15},
url = {http://www.sciencedirect.com/science/article/pii/S0925963597002604?via%3Dihub},
doi = {https://doi.org/10.1016/S0925-9635(97)00260-4}
}
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Microscopic structural quality of large area highly oriented diamond on silicon substrates for active electronic applications D. Steinbach, A.F.H.G.R. Zachai, A. Bergmaier and G. Dollinger; In: Electrochemical Society Proceedings (1998) 521 . [BibTeX] |
BibTeX:
@inproceedings{Steinbach1998,
author = {Steinbach, D. and A. Flöter H. Güttler R. Zachai and Bergmaier, A. and Dollinger, G.},
title = {Microscopic structural quality of large area highly oriented diamond on silicon substrates for active electronic applications},
booktitle = {Electrochemical Society Proceedings},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
pages = {521}
}
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Impurity and defect incorporation in diamond films deposited at low substrate temperatures J. Stiegler, A. Bergmaier, J. Michler, Y. Von Kaenel, G. Dollinger and E. Blank; Diamond and Related Materials 7 (2-5) (1998) 193-199. |
| Abstract: The quality of CVD diamond films degrades severely with decreasing substrate temperatures. In this report, the impurity and defect incorporation in diamond films deposited from a carbon-hydrogen-oxygen gas system at substrate temperatures between 560 and 345 °C has been investigated using elastic recoil detection (ERD), FTIR and micro-Raman spectroscopy. In approaching the low temperature limit which coincides with the formation of cauliflower morphologies, the hydrogen incorporation rises steeply. Hydrogen contents beyond 1 at.% have been measured, roughly 20 times higher than in the upper temperature range. By contrast, there was a much smaller rate of rise in the concentration of nitrogen and oxygen, despite a marked change in the microstructure of the deposited films. At the lowest substrate temperatures, the absolute hydrogen content measured by ERD increases more steeply than those measured by FTIR spectroscopy, which refers to C-H stretch vibrations only. There is evidence that hydrogen is incorporated also in the bulk rather than being concentrated at grain boundaries as at higher temperatures. This conclusion is supported by micro-Raman spectroscopy exhibiting significant peak broadening in the low temperature region. |
BibTeX:
@article{Stiegler1998,
author = {Stiegler, J. and Bergmaier, A. and Michler, J. and Von Kaenel, Y. and Dollinger, G. and Blank, E.},
title = {Impurity and defect incorporation in diamond films deposited at low substrate temperatures},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {7},
number = {2-5},
pages = {193--199},
note = {cited By (since 1996)18},
url = {http://www.sciencedirect.com/science/article/pii/S0925963597001647?via%3Dihub},
doi = {https://doi.org/10.1016/S0925-9635(97)00164-7}
}
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Phase separation in magnetron sputtered superhard BCN thin films S. Ulrich, H. Ehrhardt, T. Theel, J. Schwan, S. Westermeyr, M. Scheib, P. Becker, H. Oechsner, G. Dollinger and A. Bergmaier; Diamond and Related Materials 7 (6) (1998) 839-844. |
| Abstract: The similar crystalline structure of diamond and cubix boron nitride suggests the synthesis of superhard thin films containing boron, carbon and nitrogen. BCN thin films have been prepared by reactive r.f.-magnetron sputtering of a hexagonal boron nitride target in an argon/acetylene atmosphere of a constant pressure of 2 × 10-2 mbar. A deposition temperature of 600°C leads to nearly hydrogen-free BCN films. At a flow ratio of 0.05% C2H2/Ar. the composition of the deposited BCN films is close to B5CN3 as a result of energy dispersive X-ray (EDX) and elastic recoil detection (ERD) measurements. By applying a r.f.-substrate bias, the ion energy has been varied at a constant ratio cf ions to film-forming particles of 4. The BCN films show a maximum in stress at an ion energy of 110eV due to knock-on subplantation of argon ions and a phase separation into carbon, boron and cubic boron nitride regions as a result of X-ray diffraction investigations. Auger electron- and infra-red spectroscopy. |
BibTeX:
@article{Ulrich1998,
author = {Ulrich, S. and Ehrhardt, H. and Theel, T. and Schwan, J. and Westermeyr, S. and Scheib, M. and Becker, P. and Oechsner, H. and Dollinger, G. and Bergmaier, A.},
title = {Phase separation in magnetron sputtered superhard BCN thin films},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {7},
number = {6},
pages = {839--844},
note = {cited By (since 1996)60},
url = {http://www.sciencedirect.com/science/article/pii/S0925963597003075?via%3Dihub},
doi = {https://doi.org/10.1016/S0925-9635(97)00307-5}
}
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Structural response and stress release of hexagonal and cubic boron nitride films due to the bombardment with 170-MeV iodine ions P. Widmayer, D. Schwertberger, M. Wenig, P. Ziemann, A. Bergmaier and G. Dollinger; Diamond and Related Materials 7 (10) (1998) 1503-1508. |
| Abstract: To investigate the stability of the cubic (c-) and the hexagonal (h-) phase of boron nitride (BN) against radiation damage induced predominantly by electronic energy loss processes of high energy density (typical value 25 keV nm-1), thin films prepared by ion-beam-assisted sputter deposition (IBAD) were irradiated at room temperature with 170-MeV iodine ions. Though the average sample stoichiometry, as continuously monitored during the irradiation by elastic recoil detection (ERD), remains unchanged in both cases, Fourier transform infra-red (FTIR) spectra as well as reflection electron energy loss spectra (REELS) taken before and after each irradiation step clearly demonstrate that c-BN is converted to h-BN, even by small ion fluences, while h-BN remains stable. Additionally, interferometric measurements indicate a dramatic stress release for both, h-BN and c-BN starting structures. In all cases, a pronounced volume expansion of the samples perpendicular to the beam direction is observed maintaining a constant mass area density as again monitored by ERD. Atomic force microscopy (AFM) on bombarded samples reveals characteristic surface features on different length scales, which can be interpreted as being due to stress release and ion track formation. These results are consistent with h-BN being the stable high-temperature phase under relaxed pressure conditions. To investigate the stability of the cubic (c-) and the hexagonal (h-) phase of boron nitride (BN) against radiation damage induced predominantly by electronic energy loss processes of high energy density (typical value 25 keV nm-1), thin films prepared by ion-beam-assisted sputter deposition (IBAD) were irradiated at room temperature with 170-MeV iodine ions. Though the average sample stoichiometry, as continuously monitored during the irradiation by elastic recoil detection (ERD), remains unchanged in both cases, Fourier transform infra-red (FTIR) spectra as well as reflection electron energy loss spectra (REELS) taken before and after each irradiation step clearly demonstrate that c-BN is converted to h-BN, even by small ion fluences, while h-BN remains stable. Additionally, interferometric measurements indicate a dramatic stress release for both, h-BN and c-BN starting structures. In all cases, a pronounced volume expansion of the samples perpendicular to the beam direction is observed maintaining a constant mass area density as again monitored by ERD. Atomic force microscopy (AFM) on bombarded samples reveals characteristic surface features on different length scales, which can be interpreted as being due to stress release and ion track formation. These results are consistent with h-BN being the stable high-temperature phase under relaxed pressure conditions. |
BibTeX:
@article{Widmayer1998,
author = {Widmayer, P. and Schwertberger, D. and Wenig, M.J. and Ziemann, P. and Bergmaier, A. and Dollinger, G.},
title = {Structural response and stress release of hexagonal and cubic boron nitride films due to the bombardment with 170-MeV iodine ions},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1998},
volume = {7},
number = {10},
pages = {1503-1508},
note = {cited By (since 1996)10},
url = {http://www.sciencedirect.com/science/article/pii/S0925963598002192},
doi = {https://doi.org/10.1016/S0925-9635(98)00219-2}
}
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1997 |
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Hydrogen in gallium nitride grown by MOCVD O. Ambacher, H. Angerer, R. Dimitrov, W. Rieger, M. Stutzmann, G. Dollinger and A. Bergmaier; Physica Status Solidi (A) Applied Research 159 (1) (1997) 105-119. |
| Abstract: The role of hydrogen in gallium nitride was studied on thin films of GaN on sapphire prepared at substrate temperatures in the range of 600 to 1100°C. By using triethylgallium and ammonia as precursor and hydrogen and/or nitrogen as transport gases, we have observed a strong influence of molecular hydrogen on the deposition rate and the structural properties of epitaxial GaN. By elastic recoil detection analysis and thermal desorption measurements we were able to determine the total concentration of nitrogen, hydrogen and carbon in the bulk material. Isotope substitution of hydrogen by deuterium in the H2 carrier gas did not give rise to a noticeable deuterium incorporation, showing that the sources for hydrogen are the metalorganic precursor, ammonia or reaction products of both. Once incorporated, thermally activated hydrogen effusion from n-type GaN occurs with an activation energy of more than 3.9 eV. With the help of mass spectrometry we established hydrogen effusion from heavily magnesium-doped (2 at%) GaN at temperatures between 600 and 700°C, which is the temperature range used for acceptor activation. |
BibTeX:
@article{Ambacher1997,
author = {Ambacher, O. and Angerer, H. and Dimitrov, R. and Rieger, W. and Stutzmann, M. and Dollinger, G. and Bergmaier, A.},
title = {Hydrogen in gallium nitride grown by MOCVD},
journal = {Physica Status Solidi (A) Applied Research},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1997},
volume = {159},
number = {1},
pages = {105--119},
note = {cited By (since 1996)35},
url = {http://onlinelibrary.wiley.com/doi/10.1002/1521-396X(199701)159:1%3C105::AID-PSSA105%3E3.0.CO;2-H/abstract},
doi = {https://doi.org/10.1002/1521-396X(199701)159:1%3C105::AID-PSSA105%3E3.0.CO;2-H}
}
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Characterization of AlxGa1-xN films prepared by plasma-induced molecular-beam epitaxy on c-plane sapphire H. Angerer, O. Ambacher, M. Stutzmann, T. Metzger, R. Hopler, E. Born, A. Bergmaier and G. Dollinger; In: , C.R. Abernathy, H. Amano and J.C. Zolper (Ed.), Materials Research Society Symposium - Proceedings 468 (1997) 305-310 , Materials Research Society, Pittsburgh, PA, United States. |
| Abstract: AlxGa1-xN films were grown on c-plane sapphire by plasma induced modular beam epitaxy with 0 ≤ x ≤ 1. The composition and purity of the AlxGa1-xN layers was determined by elastic recoil deletion analysis with a relative error of 5% for the Al content. Both X-ray diffraction and atomic force microscopy indicate only a slight decrease in epitaxial quality of the AlxGa1-xN films with increasing Al content up to x = 0.65. X-ray diffraction is used to separate the effects of thermally induced biaxial compressive stress and the alloy composition on the shift of interplanar spacings by measuring both lattice constants. The deviation of the c/a ratio from that of fully relaxed films is a quantitative measure of the biaxial compressive stress leading to a distortion of the unit cell. Values up to 0.5 GPa were observed. By the method proposed, the determination of alloy composition can be corrected for this effect. The results obtained by this method are in very good agreement with the elastic recoil detection measurements substantiating the validity of Vegard's law. These results, compared with optical measurements, indicate that the bowing parameter of the optical bandgap is 1.3 eV within the experimental error. |
BibTeX:
@inproceedings{Angerer1997,
author = {Angerer, H. and Ambacher, O. and Stutzmann, M. and Metzger, T. and Hopler, R. and Born, E. and Bergmaier, A. and Dollinger, G.},
title = {Characterization of AlxGa1-xN films prepared by plasma-induced molecular-beam epitaxy on c-plane sapphire},
booktitle = {Materials Research Society Symposium - Proceedings},
publisher = {Materials Research Society, Pittsburgh, PA, United States},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1997},
volume = {468},
pages = {305--310},
editor = {Abernathy C.R., Amano H., Zolper J.C.},
note = {cited By (since 1996)1},
url = {https://www.cambridge.org/core/journals/mrs-online-proceedings-library-archive/article/div-classtitlecharacterisation-of-alspan-classsubxspangaspan-classsub1-xspann-films-prepared-by-plasma-induced-molecular-beam-epitaxy-on-c-plane-sapphirediv/885D83F4B16AE5A1BC74872EA731B0C3},
doi = {https://doi.org/10.1557/PROC-468-305}
}
|
|
Determination of the Al mole fraction and the band gap bowing of epitaxial AlxGa1-xN films H. Angerer, D. Brunner, F. Freudenberg, O. Ambacher, M. Stutzmann, R. Höpler, T. Metzger, E. Born, G. Dollinger, A. Bergmaier, S. Karsch and H.-J. Körner; Applied Physics Letters 71 (11) (1997) 1504-1506. |
| Abstract: AlxGa1-xN alloys were grown on c-plane sapphire by plasma-induced molecular beam epitaxy. The Al content x was varied over the whole composition range (0≤x≤1). The molar Al fraction was deduced from x-ray diffraction and for comparison by elastic recoil detection analysis. The composition of the alloys calculated from the lattice parameter c underestimates x. This is due to a deformation of the unit cell. The exact Al mole fraction and the biaxial strain of the alloys can be calculated by an additional determination of a, using asymmetric reflections. The results obtained by x-ray diffraction and elastic recoil detection provide evidence for the validity of Vegard's law in the AlGaN system. In addition, the deviation of the band gap from a linear dependence on x was investigated. We found a downward bowing with a bowing parameter b=1.3 eV. |
BibTeX:
@article{Angerer1997a,
author = {Angerer, H. and Brunner, D. and Freudenberg, F. and Ambacher, O. and Stutzmann, M. and Höpler, R. and Metzger, T. and Born, E. and Dollinger, G. and Bergmaier, A. and Karsch, S. and Körner, H.-J.},
title = {Determination of the Al mole fraction and the band gap bowing of epitaxial AlxGa1-xN films},
journal = {Applied Physics Letters},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1997},
volume = {71},
number = {11},
pages = {1504-1506},
note = {cited By (since 1996)179},
url = {http://aip.scitation.org/doi/10.1063/1.119949},
doi = {https://doi.org/10.1063/1.119949}
}
|
|
Elemental analysis on group-III nitrides using heavy ion ERD G. Dollinger, S. Karsch, O. Ambacher, H. Angerer, A. Bergmaier, O. Schmelmer and M. Stutzmann; In: , S.R. Phillpot, P.D. Bristowe, D.G. Stroud and J.R. Smith (Ed.), Proceedings of the 1997 MRS Fall Meeting; Boston, MA, USA; ; 1-4 December 1997; Code 48274 482 (1997) 745-756 , MRS, Warrendale, PA, United States. |
| Abstract: Elastic recoil detection (ERD) using energetic heavy ion beams is used to measure depth profiles of light and medium heavy elements in thin films. The main advantages of ERD are the possibilities of obtaining reliable and quantitative results, a sensitivity in the ppm region or a depth resolution even better than 1 nm. ERD analysis is employed to obtain quantitative information about the aluminum content of molar fraction in MBE grown AlxGa1-xN layers on Al2O3 substrates. Nitridation of heated Al2O3 substrates in NH3 atmosphere is investigated using high resolution ERD. The impurity content of group III nitrides is investigated on deposition conditions for both MBE and MOCVD grown samples. |
BibTeX:
@inproceedings{Dollinger1997,
author = {Dollinger, G. and Karsch, S. and Ambacher, O. and Angerer, H. and Bergmaier, A. and Schmelmer, O. and Stutzmann, M.},
title = {Elemental analysis on group-III nitrides using heavy ion ERD},
booktitle = {Proceedings of the 1997 MRS Fall Meeting; Boston, MA, USA; ; 1-4 December 1997; Code 48274},
publisher = {MRS, Warrendale, PA, United States},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1997},
volume = {482},
pages = {745--756},
editor = {Phillpot S.R., Bristowe P.D., Stroud D.G., Smith J.R.},
note = {cited By (since 1996)1},
url = {https://www.cambridge.org/core/societies/materials-research-society}
}
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|
Improvement of the preparation procedure of carbon stripper foils from the laser plasma ablation-deposition process P. Maier-Komor, A. Bergmaier, G. Dollinger, C. Frey and H. Körner; Nuclear Instruments and Methods in Physics Research Section A 397 (1) (1997) 131-136. |
| Abstract: Due to series production of the 4 μg/cm2 thick carbon stripper foils, prepared by laser plasma ablation-deposition, several improvements of the preparation procedure could be realized without impairing the crystal structure of random orientation, which leads to the insensitiveness against irradiation damage caused by swift heavy ions. Now carbon stripper foils of this kind can be floated and slackened without any plastic support. The mechanical strength of such foils was tested in dependence of ablation parameters and compared to carbon foils prepared by evaporation-condensation. So far the laser plasma ablation procedure for carbon was limited to a maximum thickness of about 10 μg/cm2. Investigations were performed to extend the thickness range to 100 μg/cm2 and more. |
BibTeX:
@article{Maier-Komor1997,
author = {Maier-Komor, P. and Bergmaier, A. and Dollinger, G. and Frey, C.M. and Körner, H.J.},
title = {Improvement of the preparation procedure of carbon stripper foils from the laser plasma ablation-deposition process},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1997},
volume = {397},
number = {1},
pages = {131--136},
note = {cited By (since 1996)21},
url = {http://www.sciencedirect.com/science/article/pii/S0168900297007626},
doi = {https://doi.org/10.1016/S0168-9002(97)00762-6}
}
|
|
An UHV box coater for VUV reflective coatings on mirror substrates of up to 95 cm in diameter P. Maier-Komor, A. Bergmaier, G. Dollinger, J. Friese, S. Karsch, P. Kienle and H. Körner; Nuclear Instruments and Methods in Physics Research Section A 397 (1) (1997) 194-199. |
| Abstract: Large mirrors with excellent reflectivity in the vacuum ultraviolet (VUV) range down to 140 nm are needed for large area RICH detectors with CsI photocathodes. This demand can only be fulfilled with a thin homogenous aluminium layer on a substrate with very low surface roughness. Due to the base metal properties of Al an excellent vacuum is required during the evaporation-condensation process. In addition the Al film needs suitable protective layers on both surfaces. The setup of pilot plants to investigate deposition parameters are described and the design of an appropriate box coater is presented. |
BibTeX:
@article{Maier-Komor1997a,
author = {Maier-Komor, P. and Bergmaier, A. and Dollinger, G. and Friese, J. and Karsch, S. and Kienle, P. and Körner, H.J.},
title = {An UHV box coater for VUV reflective coatings on mirror substrates of up to 95 cm in diameter},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1997},
volume = {397},
number = {1},
pages = {194--199},
note = {cited By (since 1996)6},
url = {http://www.sciencedirect.com/science/article/pii/S0168900297007614?via%3Dihub},
doi = {https://doi.org/10.1016/S0168-9002(97)00761-4}
}
|
1996 |
|
Thermal stability and desorption of group III nitrides prepared by metal organic chemical vapor deposition O. Ambacher, M. Brandt, R. Dimitrov, T. Metzger, M. Stutzmann, R. Fischer, A. Miehr, A. Bergmaier and G. Dollinger; Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures 14 (6) (1996) 3532-3542. |
| Abstract: We present results on the thermal stability as well as the thermally induced hydrogen, hydrocarbon, and nitrogen-hydrogen effusion from thin films of Group III nitrides prepared by low-pressure chemical vapor deposition from organometallic precursors. We have deposited amorphous, polycrystalline, and epitaxial InN, GaN, and AIN films on (0001) Al 2O 3 substrates using the chemical reaction of azido[bis(3-dimethylamino)propyl]indium, triethylgallium, and tritertiarybutylaluminium with ammonia. The substrate temperature was varied between 400 °C and 1100 °C. The elemental composition, in particular its dependence on the growth temperature, was investigated by elastic recoil detection analysis (ERDA). The influence of growth rate and crystallite size on the concentration of surface adsorbed hydrocarbons and carbon oxides is determined by a combination of ERDA and thermal desorption measurements. In addition, the stability of and the nitrogen flux from the InN, GaN, and AIN surfaces was determined by x-ray diffraction and thermal decomposition experiments. |
BibTeX:
@article{Ambacher1996,
author = {Ambacher, O. and Brandt, M.S. and Dimitrov, R. and Metzger, T. and Stutzmann, M. and Fischer, R.A. and Miehr, A. and Bergmaier, A. and Dollinger, G.},
title = {Thermal stability and desorption of group III nitrides prepared by metal organic chemical vapor deposition},
journal = {Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1996},
volume = {14},
number = {6},
pages = {3532-3542},
note = {cited By (since 1996)171},
url = {http://avs.scitation.org/doi/abs/10.1116/1.588793},
doi = {https://doi.org/10.1116/1.588793}
}
|
|
ERDA with very heavy ion beams W. Assmann, J. Davies, G. Dollinger, J. Forster, H. Huber, T. Reichelt and R. Siegele; Nuclear Instruments and Methods in Physics Research Section B 118 (1-4) (1996) 242-250. |
| Abstract: The use of very heavy ion beams such as 127I or 197Au with 1-2 MeV/u makes ERDA (elastic recoil detection analysis) a quite universal technique for thin film analysis capable of analyzing simultaneously light and heavy elements including H with almost constant sensitivity. Due to the strong increase of the recoil cross section with the projectile atomic number typically less than 10 12 ions are required to get sensitivities in the 100 ppm range. Detector systems with particle identification are advantageous for ERDA, which can be improved additionally regarding depth resolution and detection efficiency, if the kinematic energy spread is corrected. The characteristic features of heavy ion ERDA will be briefly outlined and illustrated by several examples using a position sensitive detector system. Some general problems and limitations, which are caused by heavy ion beams, will also be discussed. |
BibTeX:
@article{Assmann1996,
author = {Assmann, W. and Davies, J.A. and Dollinger, G. and Forster, J.S. and Huber, H. and Reichelt, Th. and Siegele, R.},
title = {ERDA with very heavy ion beams},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1996},
volume = {118},
number = {1-4},
pages = {242--250},
note = {cited By (since 1996)60},
url = {http://www.sciencedirect.com/science/article/pii/0168583X95011838},
doi = {https://doi.org/10.1016/0168-583X(95)01183-8}
}
|
|
Impact and characterisation of heavy ion tracks on epitaxial growth F. Baudenbacher, G. Dollinger, F. Ohnesorge, M. Bauer, W. Assman and H. Kinder; Nuclear Instruments and Methods in Physics Research Section B 107 (1-4) (1996) 327-332. |
| Abstract: The possibility of influencing the epitaxial relationship by heavy ion tracks has been investigated for high temperature superconducting films YBa 2Cu 30 7-δ (YBCO) on single crystalline MgO (100) substrates. The tracks are formed by irradiation with 120 MeV 197Au ions at incidence angles of 1.5° and 1.9° from the surface plane. AFM images of irradiated surfaces reveal the presence of channels which are on average 130 nm long and 6 nm wide. The length of the surface tracks is described by cutting a 4.3 nm deep trench diagonally at an angle of 1.9° relative to the track axis. The measured apparent depth of 1 nm agrees with this assumption due to our finite tip radius of about 20 nm. YBCO films grow on non-irradiated substrates with the in-plane epitaxial relationship YBCO[100]∥MgO[100]. Heavy ion irradiation as described above with a fluence of 10 13 Au ions/cm 2 parallel to the (110) plane resulted in an almost complete change in epitaxial alignment, yielding YBCO[100]∥MgO[110]. In contrast, the in-plane orientation of YBCO did not change if the same density of tracks was created parallel to the MgO (100) plane. Although the results demonstrate the influence of heavy ion channels on the in-plane orientation, attempts to rotate the film axis by 20° on MgO substrates failed. |
BibTeX:
@article{Baudenbacher1996,
author = {Baudenbacher, F. and Dollinger, G. and Ohnesorge, F. and Bauer, M. and Assman, W. and Kinder, H.},
title = {Impact and characterisation of heavy ion tracks on epitaxial growth},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1996},
volume = {107},
number = {1-4},
pages = {327--332},
note = {cited By (since 1996)3},
url = {http://www.sciencedirect.com/science/article/pii/0168583X95010424?via%3Dihub},
doi = {https://doi.org/10.1016/0168-583X(95)01042-4}
}
|
|
Detection of nitrogen in CVD diamond A. Bergmaier, G. Dollinger, T. Faestermann, C. Frey, M. Ferguson, H. Güttler, G. Schulz and H. Willerscheid; Diamond and Related Materials 5 (9) (1996) 995-997. |
| Abstract: A series of CVD diamond films was analysed for their nitrogen content by high resolution elastic recoil detection (ERD) in order to investigate the incorporation of nitrogen from the gas phase in a CVD reactor into the growing diamond film. CVD diamond films were deposited from a mixture of 1.5% CH 4 in H 2 and an admixture of nitrogen gas varying from 0.33% up to 67% [N]/[C]. The measurements revealed that the probability of nitrogen incorporation is only about 0.4% with respect to carbon. In addition, the morphology and texture of the polycrystalline films were investigated by scanning electron microscopy and X-ray texture analysis and showed a significant dependence on the nitrogen admixture. |
BibTeX:
@article{Bergmaier1996,
author = {Bergmaier, A. and Dollinger, G. and Faestermann, T. and Frey, C.M. and Ferguson, M. and Güttler, H. and Schulz, G. and Willerscheid, H.},
title = {Detection of nitrogen in CVD diamond},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1996},
volume = {5},
number = {9},
pages = {995--997},
note = {cited By (since 1996)25},
url = {http://www.sciencedirect.com/science/article/pii/0925963595003452},
doi = {https://doi.org/10.1016/0925-9635(95)00345-2}
}
|
|
Limits in elastic recoil detection analysis with heavy ions G. Dollinger, M. Boulouednine, A. Bergmaier, T. Faestermann and C. Frey; Nuclear Instruments and Methods in Physics Research Section B 118 (1-4) (1996) 291-300. |
| Abstract: Severe alterations of the sample by the ion beam limits the detectable concentrations in elastic recoil detection analyses (ERDA). Therefore, sputtering and effusion yields were determined and an enhancement was found in comparison to collisional theory. The sputter yield ranges from 650 carbon atoms per incident 120 MeV 197Au ion to about 2500 for hydrogen of a hydrogenated polycrystalline c-BN layer for 60 MeV 58Ni ions, and up to several millions of CHx for organic materials using 60 MeV 127I ions. In addition plural scattering and secondary reactions limit sensitivity, especially when probing materials which mainly contain light elements. The actual limits in ERD with respect to depth resolution and sensitivity are discussed in terms of these principle effects and those induced by the used detection systems. |
BibTeX:
@article{Dollinger1996,
author = {Dollinger, G. and Boulouednine, M. and Bergmaier, A. and Faestermann, T. and Frey, C.M.},
title = {Limits in elastic recoil detection analysis with heavy ions},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1996},
volume = {118},
number = {1-4},
pages = {291--300},
note = {cited By (since 1996)39},
url = {http://www.sciencedirect.com/science/article/pii/0168583X95014691},
doi = {https://doi.org/10.1016/0168-583X(95)01469-1}
}
|
|
Charge state dependence of the stopping power of 1 MeV/A 58Ni ions C. Frey, G. Dollinger, A. Bergmaier, T. Faestermann and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section B 107 (1-4) (1996) 31-35. |
| Abstract: The dependence of the energy loss of 60 MeV 58Ni ions on the incident and analysed charge state was measured in thin carbon foils with a Q3D magnetic spectrograph. The surface contamination of the carbon foils was determined by elastic scattering of 12 MeV protons and included in the analysis of the energy loss data. Five incident charge states between qin = 8 + and qin = 18 + were selected. A reduction of the stopping power in the first few atomic layers is observed for low incident charge states and an enhancement for high ones with the transition occurring at qin ≈ 13.5. The results are discussed in terms of a reduction of the dynamic screening of the effective charge of the projectiles at the target surface. |
BibTeX:
@article{Frey1996,
author = {Frey, C.M. and Dollinger, G. and Bergmaier, A. and Faestermann, T. and Maier-Komor, P.},
title = {Charge state dependence of the stopping power of 1 MeV/A 58Ni ions},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1996},
volume = {107},
number = {1-4},
pages = {31--35},
note = {cited By (since 1996)25},
url = {http://www.sciencedirect.com/science/article/pii/0168583X95010084?via%3Dihub},
doi = {https://doi.org/10.1016/0168-583X(95)01008-4}
}
|
|
Hydrogen incorporation during nucleation and growth of c-BN films M. Kuhr, R. Freudenstein, S. Reinke, W. Kulisch, G. Dollinger and A. Bergmaier; Diamond and Related Materials 5 (9) (1996) 984-989. |
| Abstract: The hydrogen content of BN films deposited by the ICP plasma method from trimethyl borazine and N2 has been investigated integrally and spatially resolved by elastic recoil detection. Hydrogen contents between 15% and 25% have been found for conditions allowing the formation of c-BN compared with 4%-10% for h-BN conditions (low bias voltages). However, under c-BN conditions hydrogen is concentrated within the sp2 parts of the film, particularly within the nucleation layer. Addition of hydrogen to the gas phase prevents the formation of c-BN and leads to h-BN films with high hydrogen contents. FTIR examination shows that the films do not contain BH and NH bonds; traces of OH and CHx do not add up to the total hydrogen content. Therefore most of the hydrogen must be free, for example incorporated on interstitials. |
BibTeX:
@article{Kuhr1996,
author = {Kuhr, M. and Freudenstein, R. and Reinke, S. and Kulisch, W. and Dollinger, G. and Bergmaier, A.},
title = {Hydrogen incorporation during nucleation and growth of c-BN films},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1996},
volume = {5},
number = {9},
pages = {984--989},
note = {cited By (since 1996)18},
url = {http://www.sciencedirect.com/science/article/pii/0925963595004726?via%3Dihub},
doi = {https://doi.org/10.1016/0925-9635(95)00472-6}
}
|
|
The effect of hydrogen on the nucleation and growth of c-bn M. Kuhr, R. Freudenstein, S.R.W. Kulisch, G. Dollinger and A. Bergmaier; J. Chem. Vap. Dep. (Technomic Publ. Co.) 3 (1996) 259. |
BibTeX:
@article{Kuhr1996a,
author = {Kuhr, M. and Freudenstein, R. and S. Reinke W. Kulisch and Dollinger, G. and Bergmaier, A.},
title = {The effect of hydrogen on the nucleation and growth of c-bn},
journal = {J. Chem. Vap. Dep. (Technomic Publ. Co.)},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1996},
volume = {3},
pages = {259}
}
|
|
Codeposition of hydrogen with beryllium, carbon and tungsten M. Mayer, R. Behrisch, H. Plank, J. Roth, G. Dollinger and C. Frey; Journal of Nuclear Materials 230 (1) (1996) 67-73. |
| Abstract: The trapping of energetic deuterium codeposited with beryllium, carbon and tungsten has been measured on a silicon collector probe at room temperature. The subsequent release of the trapped deuterium at elevated temperatures was determined by thermal desorption spectroscopy. At room temperature, deuterium codeposits both with carbon and BeO with a ration of 0.41 D-atoms/C-atom and 0.38 D-atoms/BeO, respectively. No codeposition of deuterium with tungsten is observed. The thermal release of codeposited hydrogen from BeO begins at 400 K. All hydrogen is released at temperatures above 800 K. |
BibTeX:
@article{Mayer1996,
author = {Mayer, M. and Behrisch, R. and Plank, H. and Roth, J. and Dollinger, G. and Frey, C.M.},
title = {Codeposition of hydrogen with beryllium, carbon and tungsten},
journal = {Journal of Nuclear Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1996},
volume = {230},
number = {1},
pages = {67--73},
note = {cited By (since 1996)54},
url = {http://www.sciencedirect.com/science/article/pii/0022311595002391?via%3Dihub},
doi = {https://doi.org/10.1016/0022-3115(95)00239-1}
}
|
1995 |
|
Elemental composition of thin c-BN layers A. Bergmaier, G. Dollinger, T. Faestermann, C. Frey, W. Dworschak and H. Ehrhardt; Diamond and Related Materials 4 (4) (1995) 478-481. |
| Abstract: Some experiments on the growth of cubic boron nitride (c-BN) show that the content of c-BN in BN films depends on the film thickness. Non-cubic phases, such as amorphous and hexagonal BN, can be identified, particularly near the substrate. To understand these phase variations, elemental depth profiles of thin BN films were measured by high resolution elastic recoil detection (ERD). BN films have been prepared by r.f. glow discharge (r.f = 13.56 MHz) from a mixture of B2H6 (10% in argon) and N2. Layers 48 nm and 90 nm thick have been deposited on crystalline silicon with integrated portions of the cubic phase of 55% and 67% respectively. ERD measurements showed that the integrated boron-to-nitrogen ratio is close to unity for the thicker film, but significant enhancements of boron are found near the interface with the silicon substrate and at the surface. These enhancements are coupled with a decrease in the hydrogen content, which is about 9% on average. The elemental fluctuations will be correlated with the occurrence of different BN phases and improvements for c-BN deposition will be suggested. |
BibTeX:
@article{Bergmaier1995,
author = {Bergmaier, A. and Dollinger, G. and Faestermann, T. and Frey, C.M. and Dworschak, W. and Ehrhardt, H.},
title = {Elemental composition of thin c-BN layers},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1995},
volume = {4},
number = {4},
pages = {478--481},
note = {cited By (since 1996)13},
url = {http://www.sciencedirect.com/science/article/pii/0925963594052522},
doi = {https://doi.org/10.1016/0925-9635(94)05252-2}
}
|
|
Quantitative elastic recoil detection A. Bergmaier, G. Dollinger and C. Frey; Nuclear Instruments and Methods in Physics Research Section B 99 (1-4) (1995) 488-490. |
| Abstract: Quantitative depth profiles of light and medium heavy elements can be obtained by elastic recoil detection analysis (ERDA) with heavy ions due to well known scattering cross sections and stopping powers. However, the transformation of the measured spectra (count rate versus energy) into concentration profiles is a nontrivial task in general. Therefore, based on a similar algorithm for the transformation of RBS-spectra a matrix algorithm was developed which allows to transform ERDA-spectra directly into depth profiles. This procedure can also be used to calculate depth profiles from high resolution experiments where a depth resolution better than 1 nm can be achieved. An example of ERDA-measurements demonstrates the performance of this method in determining quantitative depth profiles. |
BibTeX:
@article{Bergmaier1995a,
author = {Bergmaier, A. and Dollinger, G. and Frey, C.M.},
title = {Quantitative elastic recoil detection},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1995},
volume = {99},
number = {1-4},
pages = {488--490},
note = {cited By (since 1996)46},
url = {http://www.sciencedirect.com/science/article/pii/0168583X94006660?via%3Dihub},
doi = {https://doi.org/10.1016/0168-583X(94)00666-0}
}
|
|
Quantitative elastic recoil detection (ERD) A. Bergmaier, G. Dollinger, C. Frey and T. Faestermann; Fresenius' Journal of Analytical Chemistry 353 (5-8) (1995) 582-584. |
| Abstract: Elastic recoil detection with heavy ions is a well suited method to measure depth profiles of light and medium heavy elements in thin films. Due to known Rutherford scattering cross sections and stopping powers of ions in matter, measurements can be quantified with an accuracy of about 1%. The transformation of energy spectra to quantitative elemental depth profiles, however, is generally a non trivial task and therefore a transofrmation algorithm has been developed based on a similar one for RBS analysis and realised in the program KONZERD. The transformation procedure allows a fast conversion from raw spectra to concentration profiles for classical ERD measurements as well as for high resolution measurements with a depth resolution better than 1 nm. |
BibTeX:
@article{Bergmaier1995b,
author = {Bergmaier, A. and Dollinger, G. and Frey, C.M. and Faestermann, T.},
title = {Quantitative elastic recoil detection (ERD)},
journal = {Fresenius' Journal of Analytical Chemistry},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1995},
volume = {353},
number = {5-8},
pages = {582--584},
note = {cited By (since 1996)1},
url = {http://link.springer.com/article/10.1007%2FBF00321328},
doi = {https://doi.org/10.1007/BF00321328}
}
|
|
High resolution depth profile analysis by elastic recoil detection with heavy ions G. Dollinger, A. Bergmaier, T. Faestermann and C. Frey; Fresenius' Journal of Analytical Chemistry 353 (3-4) (1995) 311-315. |
| Abstract: Elastic recoil detection (ERD) with energetic heavy ions (e.g. 60-120 MeV127I) is a suitable method to measure depth profiles of light and medium heavy elements in thin films. The advantages of this method are reliable and quantitative results and elementally and isotopically resolved depth profiles. A relative energy resolution of 0.07% has been measured in real ERD-experiments using the Q3D magnetic spectrograph at the Munich tandem accelerator and a large solid angle of detection of 5 msr. The good energy resolution allows atomic depth resolution near to the surface which has been obtained at flat and smooth carbon samples. A large solid angle of detection is necessary to measure a depth profile with the desired accuracy before the sample is significantly altered by the ion beam. As an example carbon profiles of thin carbon layers, prepared by a laser plasma ablation deposition process, have been investigated revealing the high depth resolution and its power to resolve elemental profiles at gradiated interfaces. |
BibTeX:
@article{Dollinger1995,
author = {Dollinger, G. and Bergmaier, A. and Faestermann, T. and Frey, C.M.},
title = {High resolution depth profile analysis by elastic recoil detection with heavy ions},
journal = {Fresenius' Journal of Analytical Chemistry},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1995},
volume = {353},
number = {3-4},
pages = {311--315},
note = {cited By (since 1996)23},
url = {http://link.springer.com/article/10.1007%2FBF00322058},
doi = {https://doi.org/10.1007/BF00322058}
}
|
|
Impurities of light elements in CVD diamond G. Dollinger, A. Bergmaier, C. Frey, M. Roesler and H. Verhoeven; Diamond and Related Materials 4 (5-6) (1995) 591-595. |
| Abstract: CVD diamond samples were investigated for their content of light elements and their influence on the physical properties by high resolution elastic recoil detection (ERD) analysis. ERD allows quantitative measurements of depth profiles for all light elements with a depth resolution better than 1 nm (near the surface) using 58Ni or 127I ions with a specific energy of about 1 MeV per nucleus and a high resolution magnetic spectrograph. The measurements were focused on the content of hydrogen in (100)-oriented CVD diamond 90 μm thick grown on (100) silicon. The hydrogen content varied from 0.07 at.% in the bulk to several atomic per cent for fine crystalline diamond near the interface to its silicon substrate. The hydrogen coverage of (100)-oriented diamond could also be determined to be near the value which is expected if the (100) surface has a (2 × 1) reconstruction. In addition to hydrogen, other light elements were simultaneously measured. Silicon and oxygen impurities were also analysed in order to get information about their physical relevance. A correlation between the Si content and the luminescence of silicon centres was attempted. |
BibTeX:
@article{Dollinger1995a,
author = {Dollinger, G. and Bergmaier, A. and Frey, C.M. and Roesler, M. and Verhoeven, H.},
title = {Impurities of light elements in CVD diamond},
journal = {Diamond and Related Materials},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1995},
volume = {4},
number = {5-6},
pages = {591--595},
note = {cited By (since 1996)30},
url = {http://www.sciencedirect.com/science/article/pii/0925963594052743},
doi = {https://doi.org/10.1016/0925-9635(94)05274-3}
}
|
|
Calcium targets with low hydrogen content G. Dollinger, T. Faestermann, C. Frey and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section A 362 (1) (1995) 60-63. |
| Abstract: The hydrogen content of calcium targets was determined by elastic recoil detection (ERD). Thereby a Q3D magnetic spectrograph was used to obtain best depth resolution of the hydrogen profiles. The two most promising preparation methods for calcium targets with low hydrogen content - deposition of the most stable calcium halide CaF2 and protecting metallic Ca by a diffusion barrier of Al - have been examined. A detailed description of the technique that resulted in the minimal hydrogen content of the targets will be given. |
BibTeX:
@article{Dollinger1995b,
author = {Dollinger, G. and Faestermann, T. and Frey, C.M. and Maier-Komor, P.},
title = {Calcium targets with low hydrogen content},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1995},
volume = {362},
number = {1},
pages = {60--63},
note = {cited By (since 1996)1},
url = {http://www.sciencedirect.com/science/article/pii/0168900295003118?via%3Dihub},
doi = {https://doi.org/10.1016/0168-9002(95)00311-8}
}
|
|
Charge state dependence of the stopping power of 1 Mev/A 58Ni-ions in thin carbon foils C. Frey, G. Dollinger, A. Bergmaier, T. Faestermann and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section B 99 (1-4) (1995) 205-209. |
| Abstract: Energy loss and energy straggling of 60 MeV 58Ni ions in ultrathin carbon foils (0.8 to 30 μg/cm2) have been measured with a Q3D magnetic spectrograph in dependence on the incident and analysed charge state of the ions. The stopping power in the first few atomic layers deviates significantly from the value in larger depths and can be scaled with the square of the incident charge state q. For larger depths the stopping power coincides with the tabulated value for all measured charge states. From this difference in the stopping power an average charge state q = 15.5 for the Ni-ions inside the bulk can be estimated in a first approximation. With the average charge state behind carbon foils being q = 17.6 the ion has to lose two electrons on average when leaving the target, e.g. by Auger processes. The energy straggling of the Ni-ions can be approximated by the known formula of Bohr. Nevertheless the systematics of the dependence on the incident and analysed charge state indicates that charge changing events contribute a significant amount to the energy straggling. |
BibTeX:
@article{Frey1995,
author = {Frey, C.M. and Dollinger, G. and Bergmaier, A. and Faestermann, T. and Maier-Komor, P.},
title = {Charge state dependence of the stopping power of 1 Mev/A 58Ni-ions in thin carbon foils},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1995},
volume = {99},
number = {1-4},
pages = {205--209},
note = {cited By (since 1996)11},
url = {http://www.sciencedirect.com/science/article/pii/0168583X95002189?via%3Dihub},
doi = {https://doi.org/10.1016/0168-583X(95)00218-9}
}
|
|
Completion of the plant for laser plasma ablation-deposition of carbon P. Maier-Komor, G. Dollinger, C. Frey and H. Körner; Nuclear Instruments and Methods in Physics Research Section A 362 (1) (1995) 208-212. |
| Abstract: The strength of carbon stripper foils against heavy ion induced irradiation damage is at an optimum if the nanocrystals of the carbon foil are isotropically distributed. So far only carbon stripper foils prepared by laser plasma ablation deposition can completely fulfill this demand. This procedure is quite different from standard carbon foil preparation and needs several new developments especially for a series production. Here the realization of the previously measured ablation deposition data into a source-to-substrate configuration is demonstrated. For the total rotating substrate area of 750 cm2, an overall homogeneity of 3% could be attained with a small source-to-substrate distance of 40 cm. Problems being encountered from the high laser power density especially at the laser to vacuum entrance window have been solved. Investigations of suitable parting agents and parting agent combinations which are less sensitive on humidity were performed. Even if not all problems are solved with satisfaction, a routine preparation can be started now. |
BibTeX:
@article{Maier-Komor1995,
author = {Maier-Komor, P. and Dollinger, G. and Frey, C.M. and Körner, H.J.},
title = {Completion of the plant for laser plasma ablation-deposition of carbon},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1995},
volume = {362},
number = {1},
pages = {208--212},
note = {cited By (since 1996)18},
url = {http://www.sciencedirect.com/science/article/pii/0168900295004130},
doi = {https://doi.org/10.1016/0168-9002(95)00413-0}
}
|
1994 |
|
Depth microscopy at interfaces G. Dollinger, T. Faestermann, C. Frey, A. Bergmaier, E. Schwabedissen, T. Fischer and R. Schwarz; Nuclear Instruments and Methods in Physics Research Section B 85 (1-4) (1994) 786-789. |
| Abstract: High resolution depth microscopy with swift heavy ions is performed at the Munich tandem accelerator and its Q3D magnetic spectrograph using the elastic recoil detection technique. The method gives the possibility to analyze elemental and isotopic concentration profiles of light and medium heavy atoms in thin films and at interfaces. A monitor detector has been installed in the scattering chamber of the Q3D in order to get the relative elemental content for the high resolution depth profiles without absolute knowledge of beam current and charge yields. It is a detector telescope which consists of an ionisation chamber for energy loss and a silicon detector for a residual energy measurement in order to obtain the nuclear charge of the detected target atoms. Depth microscopy was applied for quantitative analysis of concentration profiles at the interfaces between a-Si : H and a-SiC : H layers. Hydrogen profiles can directly be compared to carbon and oxygen profiles showing an excess hydrogen content at the interface between the two layers. |
BibTeX:
@article{Dollinger1994,
author = {Dollinger, G. and Faestermann, T. and Frey, C.M. and Bergmaier, A. and Schwabedissen, E. and Fischer, Th. and Schwarz, R.},
title = {Depth microscopy at interfaces},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1994},
volume = {85},
number = {1-4},
pages = {786--789},
note = {cited By (since 1996)5},
url = {http://www.sciencedirect.com/science/article/pii/0168583X94959242},
doi = {https://doi.org/10.1016/0168-583X(94)95924-2}
}
|
1993 |
|
Elastic recoil detection analysis with atomic depth resolution G. Dollinger; Nuclear Instruments and Methods in Physics Research Section B 79 (1-4) (1993) 513-517. |
| Abstract: Elastic recoil detection analysis (ERD) with swift heavy ions has been improved in view of depth resolution. Profiles of light elements could be measured in carbon near the surface with single atomic layer resolution using 58Ni, 127I or 197Au beams with energies between 0.5 A MeV and 1 A MeV and a Q3D magnetic spectrograph. Due to the specific ion optical arrangement of the Q3D a relative energy resolution of about 7 × 10-4 was achieved in ERD experiments although a large solid angle of 5 msr was used. This large acceptance guarantees good statistics even with low ion fluences. In this way the elemental concentration profiles are not essentially disturbed by irradiation damage effects and can be measured in the 0.1% level on an atomic depth scale. |
BibTeX:
@article{Dollinger1993,
author = {Dollinger, G.},
title = {Elastic recoil detection analysis with atomic depth resolution},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1993},
volume = {79},
number = {1-4},
pages = {513--517},
note = {cited By (since 1996)15},
url = {http://www.sciencedirect.com/science/article/pii/0168583X9395402Q},
doi = {https://doi.org/10.1016/0168-583X(93)95402-Q}
}
|
|
Depth microscopy for thin film analysis G. Dollinger, M. Boulouednine, T. Faestermann and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section A 334 (1) (1993) 187-190. |
| Abstract: Depth microscopy with swift heavy ions has recently been developed. It is an elastic recoil detection technique with high depth resolution performed at the Munich tandem accelerator and its Q3D magnetic spectrograph. The method provides the possibility of analyzing elemental and isotopic concentration profiles in thin films and foils with high accuracy up to single layer depth resolution near the surface. This technique was applied to examine surface and bulk concentrations of hydrogen in thin carbon foils and carbon films deposited with different deposition techniques. In addition, mixing zones were investigated between silicon substrates and carbon films deposited by ablation of carbon with a Nd:YAG laser at different light intensities. The width of the mixing zone strongly depends on the light intensity for the laser ablation and varies from 0.6 μg/cm2 for a power density of 2 GW/cm2 to 2.5 μg/cm2 for 20 GW/cm2. |
BibTeX:
@article{Dollinger1993a,
author = {Dollinger, G. and Boulouednine, M. and Faestermann, T. and Maier-Komor, P.},
title = {Depth microscopy for thin film analysis},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1993},
volume = {334},
number = {1},
pages = {187--190},
note = {cited By (since 1996)6},
url = {http://www.sciencedirect.com/science/article/pii/016890029390549W?via%3Dihub},
doi = {https://doi.org/10.1016/0168-9002(93)90549-W}
}
|
|
Laser plasma ablation of carbon G. Dollinger, C. Frey and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section A 334 (1) (1993) 167-172. |
| Abstract: A new plant for fabricating carbon stripper foils by laser plasma ablation-deposition has been installed. The adaptation of the preparation process to the ultrahigh vacuum system and the pulsed (≈ 10 ns pulse width) Nd:YAG laser with a repetition rate of 50 Hz is described. Carbon deposition rates were measured as a function of laser power density, polar angle θsymbol and azimuth angle φsymbol, where the central laser beam defines the polar axis. The crystal structure of the ≈ 4 μg/cm2 thick carbon foils was analyzed with respect to laser power density and polar angle θsymbol. In addition, the specific gravity and resistivity of such carbon foils were measured in relation to the laser power density for carbon films mounted during deposition at θsymbol = 14°. |
BibTeX:
@article{Dollinger1993b,
author = {Dollinger, G. and Frey, C.M. and Maier-Komor, P.},
title = {Laser plasma ablation of carbon},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1993},
volume = {334},
number = {1},
pages = {167--172},
note = {cited By (since 1996)15},
url = {http://www.sciencedirect.com/science/article/pii/016890029390546T},
doi = {https://doi.org/10.1016/0168-9002(93)90546-T}
}
|
|
New plant for fabricating carbon stripper foils by laser plasma ablation deposition G. Dollinger, P. Maier-Komor, C. Frey, E. Hammann and H. Körner; Nuclear Instruments and Methods in Physics Research Section A 328 (1-2) (1993) 168-172. |
| Abstract: Our theory on the optimum strength of carbon stripper foils with respect to heavy ion induced irradiation damage at tandem energies was confirmed when newly developed carbon foils with isotropically distributed nanocrystals were tested. The new preparation method is based on a hot carbon plasma induced by 10 ns light pulses with a power density of up to 30 GW/cm2 from a Nd:YAG laser. In order to prepare the so-called lpa-foils (carbon stripper foils prepared by laser plasma ablation deposition) in series production a new ultrahigh vacuum box coater was installed. This system offers a working pressure of about 10-6 Pa and a substrate area of about 1000 cm2, which means 100-200 stripper foils per charge depending on the size of the stripper frame. A new pulsed Nd: YAG laser with a repetition rate of 50 Hz was installed at the box coater in order to shorten the deposition time. A status report of the adaptation of the lpa-process to the new setup is presented in detail. |
BibTeX:
@article{Dollinger1993c,
author = {Dollinger, G. and Maier-Komor, P. and Frey, C.M. and Hammann, E. and Körner, H.J.},
title = {New plant for fabricating carbon stripper foils by laser plasma ablation deposition},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1993},
volume = {328},
number = {1-2},
pages = {168--172},
note = {cited By (since 1996)3},
url = {http://www.sciencedirect.com/science/article/pii/016890029390620W?via%3Dihub},
doi = {https://doi.org/10.1016/0168-9002(93)90620-W}
}
|
1992 |
|
High resolution depth profiling of light elements G. Dollinger, T. Faestermann and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section B 64 (1-4) (1992) 422-427. |
| Abstract: An elastic recoil detection analysis technique with swift heavy ions has been developed to measure high resolution depth profiles of light elements in thin films and multilayer systems. A depth resolution of 1 nm was achieved with a Q3D magnetic spectrograph using a high quality 120 MeV 197Au12 beam. The depth resolution was tested with 12C recoil ions from 12C/11B multilayers. Due to the large solid angle used (2 msr) and large scattering cross sections only low ion currents ( ≈ 109 ions s) are necessary for good statistics within a few minutes of irradiation. The method was applied to depth profile analysis of light elements in a-Si:H/a-SiC:H multilayer systems. Alterations in the multilayers induced by the heavy ion beam have been observed during long lasting irradiations and might limit the depth resolution when profiling small elemental concentrations. |
BibTeX:
@article{Dollinger1992,
author = {Dollinger, G. and Faestermann, T. and Maier-Komor, P.},
title = {High resolution depth profiling of light elements},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1992},
volume = {64},
number = {1-4},
pages = {422--427},
note = {cited By (since 1996)44},
url = {http://www.sciencedirect.com/science/article/pii/0168583X9295508O?via%3Dihub},
doi = {https://doi.org/10.1016/0168-583X(92)95508-O}
}
|
1991 |
|
Carbon stripper foils with isotropic structure for optimum strength against irradiation damage G. Dollinger and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section B 53 (3) (1991) 352-354. |
| Abstract: Investigations about the irradiation damage in carbon foils [1] led to the prediction that carbon stripper foils with a structure of randomly oriented crystallites should adduce an optimum strength against damages caused by swift heavy ions. As a result of these investigations new stripper foils were developed, which are prepared by laser plasma ablation-deposition in high vacuum. Such foils are provided with the preferred crystalline structure and show the predicted improvement in tests using an 127I-beam at the Munich tandem accelerator. |
BibTeX:
@article{Dollinger1991,
author = {Dollinger, G. and Maier-Komor, P.},
title = {Carbon stripper foils with isotropic structure for optimum strength against irradiation damage},
journal = {Nuclear Instruments and Methods in Physics Research Section B},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1991},
volume = {53},
number = {3},
pages = {352--354},
note = {cited By (since 1996)19},
url = {http://www.sciencedirect.com/science/article/pii/0168900289901459?via%3Dihub},
doi = {https://doi.org/10.1016/0168-9002(89)90145-9}
}
|
|
Development of laser plasma ablation-deposition techniques for carbon stripper foils G. Dollinger and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section A 303 (1) (1991) 50-58. |
| Abstract: The aim to develop irradiation resistant carbon stripper foils for swift heavy ions led to the new technique of laser plasma ablation-deposition of carbon, in which a pulsed high power Nd:YAG laser induces a hot carbon plasma for deposition on suitable substrates in high vacuum. The essential physical property of the new technique is the ablation of monoatomic carbon with an average charge state of 4+ and a broad spectrum of energies of up to 1 keV of the monomers. These conditions influence the nucleation and growth of a carbon film in such a way that a nearly isotropic orientation of the nanocrystals in the condensed film is achieved. This results, as postulated, in a much better strength against irradiation damage caused by heavy ions, compared to all other types of stripper foils. |
BibTeX:
@article{Dollinger1991a,
author = {Dollinger, G. and Maier-Komor, P.},
title = {Development of laser plasma ablation-deposition techniques for carbon stripper foils},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1991},
volume = {303},
number = {1},
pages = {50--58},
note = {cited By (since 1996)14},
url = {http://www.sciencedirect.com/science/article/pii/016890029190763G?via%3Dihub},
doi = {https://doi.org/10.1016/0168-9002(91)90763-G}
}
|
|
Structure investigations of thin carbon foils G. Dollinger, P. Maier-Komor and A. Mitwalsky; Nuclear Instruments and Methods in Physics Research Section A 303 (1) (1991) 79-87. |
| Abstract: Carbon foils produced by laser plasma ablation-deposition (lpa-foils), by the glow discharge process (gd-foils) and by evaporation-condensation (ec-foils) were investigated by high resolution transmission electron microscopy and electron diffraction. A quantitative analysis is presented for the degree of anisotropic orientation of the quasi-graphitic nanocrystals in the polycrystalline foils. In the new type lpa-foils the nanocrystals are nearly isotropically oriented, in contrast to the anisotropic alignment in the ec-and gd-foils. This random orientation is responsible for a longer lifetime of lpa-foils when irradiated with heavy ions. |
BibTeX:
@article{Dollinger1991b,
author = {Dollinger, G. and Maier-Komor, P. and Mitwalsky, A.},
title = {Structure investigations of thin carbon foils},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1991},
volume = {303},
number = {1},
pages = {79--87},
note = {cited By (since 1996)17},
url = {http://www.sciencedirect.com/science/article/pii/016890029190767K?via%3Dihub},
doi = {https://doi.org/10.1016/0168-9002(91)90767-K}
}
|
|
Progress in target technology using a pulsed laser beam for physical vapor deposition P. Maier-Komor and G. Dollinger; Nuclear Instruments and Methods in Physics Research Section A 303 (1) (1991) 168-171. |
| Abstract: For the preparation of isotopic accelerator targets by means of an evaporation-condensation process, laser heating is a method with high efficiency and thus low consumption of expensive isotope materials. A Q-switched, pulsed Nd: YAG laser is utilized for the ablation of refractory metals, which are deposited on substrates in a vacuum of 10-5 Pa. Even for metals with low vapor pressures at their melting points, high ablation rates nearly independent of the vapor pressure can be obtained with laser pulses of 300 mJ within 10 ns. With an average laser power of 3 W, deposition rates for various metals were measured. With a source to substrate distance of 5 cm, condensation rates varied only from 70-300 ngcm-2 s-1 for the wide range of elements with lower vapor pressures from boron to uranium. |
BibTeX:
@article{Maier-Komor1991,
author = {Maier-Komor, P. and Dollinger, G.},
title = {Progress in target technology using a pulsed laser beam for physical vapor deposition},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1991},
volume = {303},
number = {1},
pages = {168--171},
note = {cited By (since 1996)4},
url = {http://www.sciencedirect.com/science/article/pii/016890029190783M},
doi = {https://doi.org/10.1016/0168-9002(91)90783-M}
}
|
|
Thickness calibration of carbon foils P. Maier-Komor, G. Dollinger and E. Hammann; Nuclear Instruments and Methods in Physics Research Section A 303 (1) (1991) 88-93. |
| Abstract: The transmittance of normally incident, monochromatic light for self-supporting carbon foils is a well-known nondestructive procedure to determine their thickness. The relationship of transmittance and foil thickness can be described using the exact analytical equation for a single unsupported layer, where the only free parameter is the complex refractive index. Using this formula, calibration curves for various data from the literature could be fitted. Explanations are given as to why carbon foils prepared even by the same procedure but in different setups show different optical parameters. The newly developed carbon foils, prepared by laser plasma ablation-deposition, were thickness calibrated in the same manner. In this case, AT-cut quartz crystals coupled to a thickness monitor were used as substrates for the thickness standards. |
BibTeX:
@article{Maier-Komor1991a,
author = {Maier-Komor, P. and Dollinger, G. and Hammann, E.},
title = {Thickness calibration of carbon foils},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1991},
volume = {303},
number = {1},
pages = {88--93},
note = {cited By (since 1996)9},
url = {http://www.sciencedirect.com/science/article/pii/016890029190768L},
doi = {https://doi.org/10.1016/0168-9002(91)90768-L}
}
|
1989 |
|
Stripper foil requirements for optimum ion transmission at the Munich MP-tandem G. Dollinger and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section A 282 (1) (1989) 153-160. |
| Abstract: The transmission of several ion beams (1H, 2H, 16O, 32S, 58Ni, 107Ag, 127I, and 197Au) through the Munich MP-tandem were measured as a function of stripper foil thickness, ion injection limitation, and analyzed charge state at 10 MV terminal voltage. These data offer the possibility to optimize the stripper foil thickness for the specific experimental requirements. In addition the knowledge could be broadened, how to choose the ion injection limitation conditions in order to achieve a high yield of the analyzed heavy ion charge state and a long lifetime of the carbon stripper foil. |
BibTeX:
@article{Dollinger1989,
author = {Dollinger, G. and Maier-Komor, P.},
title = {Stripper foil requirements for optimum ion transmission at the Munich MP-tandem},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1989},
volume = {282},
number = {1},
pages = {153--160},
note = {cited By (since 1996)7},
url = {http://www.sciencedirect.com/science/article/pii/0168900289901307?via%3Dihub},
doi = {https://doi.org/10.1016/0168-9002(89)90130-7}
}
|
|
Heavy-ion irradiation damage in carbon stripper foils G. Dollinger and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section A 282 (1) (1989) 223-235. |
| Abstract: Slackened carbon stripper foils of about 4 μg/cm2, produced by vacuum evaporation-condensation and used for heavy ion stripping in the terminal of the Munich MP tandem, were investigated in order to get more information about irradiation damages. Electron diffraction and electron transmission muscope investigations related with theoretical considerations revealed a clear picture of the irradiation damage mechanism in carbon stripper foils. Due to these results it can be predicted, how the crystallographic structure of a carbon foil should be constituted in order to show best stripper performance. |
BibTeX:
@article{Dollinger1989a,
author = {Dollinger, G. and Maier-Komor, P.},
title = {Heavy-ion irradiation damage in carbon stripper foils},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1989},
volume = {282},
number = {1},
pages = {223--235},
note = {cited By (since 1996)14},
url = {http://www.sciencedirect.com/science/article/pii/0168900289901459?via%3Dihub},
doi = {https://doi.org/10.1016/0168-9002(89)90145-9}
}
|
|
Irradiation damage in carbon stripper foils induced by heavy ions G. Dollinger and P. Maier-Komor; Radiation Effects and Defects in Solids 110 (1-2) (1989) 197-199. |
BibTeX:
@article{Dollinger1989b,
author = {Dollinger, G. and Maier-Komor, P.},
title = {Irradiation damage in carbon stripper foils induced by heavy ions},
journal = {Radiation Effects and Defects in Solids},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1989},
volume = {110},
number = {1-2},
pages = {197--199},
url = {http://www.tandfonline.com/doi/abs/10.1080/10420158908214196},
doi = {https://doi.org/10.1080/10420158908214196}
}
|
|
Final results in stripper foil development G. Dollinger and P. Maier-Komor; In: Proc. SNEAP (1989) 138 , World Scientific, New Jersey, 1990. |
BibTeX:
@inproceedings{Dollinger1989c,
author = {Dollinger, G. and P. Maier-Komor},
title = {Final results in stripper foil development},
booktitle = {Proc. SNEAP},
publisher = {World Scientific, New Jersey, 1990},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Dollinger, Günther},
year = {1989},
pages = {138}
}
|
1987 |
|
Structure studies of carbon foils with the aim to improve the ability for heavy-ion stripping G. Dollinger and P. Maier-Komor; Nuclear Instruments and Methods in Physics Research Section A 257 (1) (1987) 64-68. |
| Abstract: Slackened carbon stripper foils of 3 to 5 μg/cm2 produced by vacuum evaporation-condensation were graphitized by annealing at about 3300 K with a pulsed laser beam (1.06 μm). An average crystal size of 10 nm was measured by electron diffraction. The texture of the 002-plane is parallel to the surface of the foil as known from slightly annealed carbon foils. Radiation damages caused by high doses of heavy ions dramatically change the crystal structure. Electron diffraction patterns reveal newly formed graphite crystals with their 002-plane perpendicular to the texture. Compared to carbon foils of the same kind, but not graphitized, a lifetime prolongation of a factor of two was achieved for such foils tested in the terminal of the Munich MP tandem. The slope of the curve for heavy-ion transmission through carbon stripper foils varies for foils of the same kind and for different ion-beam conditions. |
BibTeX:
@article{Dollinger1987,
author = {Dollinger, G. and Maier-Komor, P.},
title = {Structure studies of carbon foils with the aim to improve the ability for heavy-ion stripping},
journal = {Nuclear Instruments and Methods in Physics Research Section A},
school = {Universität der Bundeswehr München, Fakultät für Luft- und Raumfahrttechnik, LRT 2 - Institut für Angewandte Physik und Messtechnik, Professur: Triftshäuser, Werner},
year = {1987},
volume = {257},
number = {1},
pages = {64--68},
note = {cited By (since 1996)2},
url = {http://www.sciencedirect.com/science/article/pii/016890028791179X},
doi = {https://doi.org/10.1016/0168-9002(87)91179-X}
}
|