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Title: Reactive dc magnetron sputtering of (GeO{sub x}-SiO{sub 2}) superlattices for Ge nanocrystal formation

Abstract

The motivation of this work is the tailored growth of Ge nanocrystals for photovoltaic applications. The use of superlattices provides a reliable method to control the Ge nanocrystal size after phase separation. In this paper, we report on the deposition of (GeO{sub x}-SiO{sub 2}) superlattices via reactive dc magnetron sputtering and the self-ordered Ge nanocrystal formation during subsequent annealing. Attention is directed mainly to define proper deposition conditions for tuning the GeO{sub x} composition between elemental Ge (x=0) and GeO{sub 2} (x=2) by the variation in the deposition temperature and the oxygen partial pressure. A convenient process window has been found which allows sequential GeO{sub x}-SiO{sub 2} deposition without changing the oxygen partial pressure during deposition. The phase separation and Ge nanocrystal formation after subsequent annealing were investigated with in situ x-ray scattering, Raman spectroscopy, and electron microscopy. By these methods the existence of 2-5 nm Ge nanocrystals at annealing temperatures of 600-750 deg. C has been confirmed which is within the superlattice stability range. The technique used allows the fabrication of superlattice stacks with very smooth interfaces (roughness<1 nm); thus the Ge nanocrystal layers could be separated by very thin SiO{sub 2} films (d<3 nm) which offers interesting possibilitiesmore » for charge transport via direct tunneling.« less

Authors:
; ; ; ;  [1]
  1. Institute of Ion Beam Physics and Materials Research, Forschungszentrum Dresden Rossendorf e.V., P.O. Box 51 01 19, 01314 Dresden (Germany)
Publication Date:
OSTI Identifier:
21476131
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 107; Journal Issue: 3; Other Information: DOI: 10.1063/1.3276184; (c) 2010 American Institute of Physics; Journal ID: ISSN 0021-8979
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; ANNEALING; CHARGE TRANSPORT; DEPOSITION; GERMANIUM OXIDES; INTERFACES; LAYERS; NANOSTRUCTURES; PHOTOVOLTAIC EFFECT; RAMAN SPECTRA; RAMAN SPECTROSCOPY; SEMICONDUCTOR MATERIALS; SILICON OXIDES; SPUTTERING; SUPERLATTICES; THIN FILMS; TRANSMISSION ELECTRON MICROSCOPY; TUNNEL EFFECT; X-RAY DIFFRACTION; CHALCOGENIDES; COHERENT SCATTERING; DIFFRACTION; ELECTRON MICROSCOPY; FILMS; GERMANIUM COMPOUNDS; HEAT TREATMENTS; LASER SPECTROSCOPY; MATERIALS; MICROSCOPY; OXIDES; OXYGEN COMPOUNDS; PHOTOELECTRIC EFFECT; SCATTERING; SILICON COMPOUNDS; SPECTRA; SPECTROSCOPY

Citation Formats

Zschintzsch, M., Jeutter, N. M., Borany, J. von, Krause, M., and Muecklich, A. Reactive dc magnetron sputtering of (GeO{sub x}-SiO{sub 2}) superlattices for Ge nanocrystal formation. United States: N. p., 2010. Web. doi:10.1063/1.3276184.
Zschintzsch, M., Jeutter, N. M., Borany, J. von, Krause, M., & Muecklich, A. Reactive dc magnetron sputtering of (GeO{sub x}-SiO{sub 2}) superlattices for Ge nanocrystal formation. United States. doi:10.1063/1.3276184.
Zschintzsch, M., Jeutter, N. M., Borany, J. von, Krause, M., and Muecklich, A. Mon . "Reactive dc magnetron sputtering of (GeO{sub x}-SiO{sub 2}) superlattices for Ge nanocrystal formation". United States. doi:10.1063/1.3276184.
@article{osti_21476131,
title = {Reactive dc magnetron sputtering of (GeO{sub x}-SiO{sub 2}) superlattices for Ge nanocrystal formation},
author = {Zschintzsch, M. and Jeutter, N. M. and Borany, J. von and Krause, M. and Muecklich, A.},
abstractNote = {The motivation of this work is the tailored growth of Ge nanocrystals for photovoltaic applications. The use of superlattices provides a reliable method to control the Ge nanocrystal size after phase separation. In this paper, we report on the deposition of (GeO{sub x}-SiO{sub 2}) superlattices via reactive dc magnetron sputtering and the self-ordered Ge nanocrystal formation during subsequent annealing. Attention is directed mainly to define proper deposition conditions for tuning the GeO{sub x} composition between elemental Ge (x=0) and GeO{sub 2} (x=2) by the variation in the deposition temperature and the oxygen partial pressure. A convenient process window has been found which allows sequential GeO{sub x}-SiO{sub 2} deposition without changing the oxygen partial pressure during deposition. The phase separation and Ge nanocrystal formation after subsequent annealing were investigated with in situ x-ray scattering, Raman spectroscopy, and electron microscopy. By these methods the existence of 2-5 nm Ge nanocrystals at annealing temperatures of 600-750 deg. C has been confirmed which is within the superlattice stability range. The technique used allows the fabrication of superlattice stacks with very smooth interfaces (roughness<1 nm); thus the Ge nanocrystal layers could be separated by very thin SiO{sub 2} films (d<3 nm) which offers interesting possibilities for charge transport via direct tunneling.},
doi = {10.1063/1.3276184},
journal = {Journal of Applied Physics},
issn = {0021-8979},
number = 3,
volume = 107,
place = {United States},
year = {2010},
month = {2}
}