Conservation of bond lengths in strained Ge-Si layers

Journal Article · Tue Jan 15 04:00:00 EST 1991 · Physical Review, B: Condensed Matter; (USA)

DOI:https://doi.org/10.1103/PhysRevB.43.2419· OSTI ID:6115017

Woicik, J C; Bouldin, C E; Bell, M I ^[1]; Cross, J O; Tweet, D J; Swanson, B D; Zhang, T M; Sorensen, L B ^[2]; King, C A; Hoyt, J L; Pianetta, P; Gibbons, J F ^[3]

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1. National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (USA)
2. Department of Physics (FM-15), University of Washington, Seattle, Washington (USA)
3. Stanford Electronics Laboratory, Stanford, California (USA)

The combined techniques of x-ray-absorption fine structure and x-ray diffraction have been used to study the strain and bond distortions in epitaxial Ge-Si on Si(001). In a 31% Ge, 340-A pseudomorphic Ge-Si film, the Ge-Ge and Ge-Si first-neighbor bond lengths have been found to be 2.44{plus minus}0.02 and 2.38{plus minus}0.02 A, respectively. The lattice parameter perpendicular to the Ge-Si/Si(001) interface has been found to be {ital a}{sub {perpendicular}}=5.552{plus minus}0.002 A, in agreement with the predictions of macroscopic elastic theory. These results show that the bond-length strain in the epitaxial layer appears in the second and higher coordination shells, rather than in the nearest-neighbor bond lengths, which remain the same as in unstrained Ge-Si. A microscopic model is presented that accounts for these findings.

• DOE Contract Number: AC02-76CH00016
• OSTI ID: 6115017
• Journal Information: Physical Review, B: Condensed Matter; (USA), Journal Name: Physical Review, B: Condensed Matter; (USA) Vol. 43:3; ISSN PRBMD; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
360603 -- Materials-- Properties
ABSORPTION SPECTROSCOPY
BOND LENGTHS
COHERENT SCATTERING
DIFFRACTION
DIMENSIONS
EPITAXY
FINE STRUCTURE
GERMANIUM COMPOUNDS
GERMANIUM SILICIDES
LAYERS
LENGTH
MATHEMATICAL MODELS
SCATTERING
SILICIDES
SILICON COMPOUNDS
SPECTRA
SPECTROSCOPY
STRAINS
X-RAY DIFFRACTION
X-RAY SPECTRA