Atomic structure and lattice dynamics of strain-compensated si_1-x-yge_xc_y layers

authored by

H. Rüecker, M. Methfessel, B. Dietrich, H. J. Osten, P. Zaumseil

Abstract

The local atomic structure and lattice dynamics are studied for strain-compensated Si_1-x-yGe_xC_y layers grown by molecular beam epitaxy on Si (001) substrates. The layers were characterized by transmission electron microscopy, x-ray diffraction, and Raman scattering and modeled using a valence-force field model. For a [Ge]/[C] ratio of approximately ten, the lattice constant in the growth direction is equal to that of the substrate, indicating an absence of macroscopic strain. Experimental and theoretical results are compatible with Vegard’s rule. To handle the large bond length distortions near C atoms properly, the valence-force field model used includes anharmonic effects via bond-length-dependent interatomic force constants which were determined from ab initio density-functional calculations. The dependence of the Raman spectra on strain and composition of Si_1-x-yGe_xC_y layers can be explained by the model calculations.

External Organisation(s)

Leibniz Institute for High Performance Microelectronics (IHP)

Type

Article

Journal

Superlattices and microstructures

Volume

16

Pages

121-124

No. of pages

4

ISSN

0749-6036

Publication date

09.1994

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

General Materials Science, Condensed Matter Physics, Electrical and Electronic Engineering

Electronic version(s)

https://doi.org/10.1006/spmi.1994.1123 (Access: Closed)