Composition and strain in thin Si{sub 1-x}Ge{sub x} virtual substrates measured by micro-Raman spectroscopy and x-ray diffraction

Journal Article · Tue Feb 01 00:00:00 EST 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3536508· OSTI ID:21538077

Perova, T S; Wasyluk, J; Waldron, A ^[1]; Lyutovich, K; Kasper, E; Oehme, M ^[2]; Rode, K ^[3]

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1. Department of Electronic and Electrical Engineering, Trinity College, University of Dublin, Dublin 2 (Ireland)
2. Institut fuer Halbleitertechnik, Universitaet Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart (Germany)
3. School of Physics, CRANN, Trinity College, University of Dublin, Dublin 2 (Ireland)

Micro-Raman spectroscopy was employed for the determination of the germanium content, x and strain, {epsilon}, in ultrathin SiGe virtual substrates grown directly on Si by molecular beam epitaxy. The growth of highly relaxed SiGe layers was achieved by the introduction of point defects at a very low temperature during the initial stage of growth. SiGe virtual substrates with thicknesses in the range 40-200 nm with a high Ge content (up to 50%) and degree of relaxation, r, in the range 20%-100% were investigated using micro-Raman spectroscopy and x-ray diffraction (XRD) techniques. The Ge content, x, and strain, {epsilon}, were estimated from equations describing Si-Si, Si-Ge, and Ge-Ge Raman vibrational modes, modified in this study for application to thin SiGe layers. The alteration of the experimentally derived equations from previous studies was performed using independent data for x and r obtained from XRD reciprocal space maps. A number of samples consisting of a strained-silicon (s-Si) layer deposited on a SiGe virtual substrate were also analyzed. The stress value for the s-Si varied from 0.54 to 2.75 GPa, depending on the Ge-content in the virtual substrates. These results are in good agreement with theoretically predicted values.

• OSTI ID: 21538077
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 3; Other Information: DOI: 10.1063/1.3536508; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
BUFFERS
DECISION MAKING
DEMAND
DISLOCATIONS
FEEDBACK
GERMANIUM ALLOYS
GERMANIUM SILICIDES
LAYERS
MOLECULAR BEAM EPITAXY
POINT DEFECTS
PRESSURE RANGE GIGA PA
RAMAN SPECTRA
RAMAN SPECTROSCOPY
RELAXATION
SEMICONDUCTOR MATERIALS
SILICON ALLOYS
STRAINS
SUBSTRATES
THIN FILMS
X-RAY DIFFRACTION
ALLOYS
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTAL GROWTH METHODS
CRYSTAL STRUCTURE
DIFFRACTION
EPITAXY
FILMS
GERMANIUM COMPOUNDS
LASER SPECTROSCOPY
LINE DEFECTS
MATERIALS
PRESSURE RANGE
SCATTERING
SILICIDES
SILICON COMPOUNDS
SPECTRA
SPECTROSCOPY