Influence of Annealing on the Interface Structure and Strain Relief in Si/Ge Heterostructures on (100) Si

Authors

D. J. Lockwood, National Research Council, Ottawa
J. -M. Baribeau, National Research Council, Ottawa
T. E. Jackman, National Research Council, Ottawa
P. Aebi, McMaster University
T. Tyliszczak, McMaster University
A. P. Hitchcock, McMaster University
R. L. Headrick, Cornell University

Abstract

Research work on the general problem of the nature and thermal stability of the Si/Ge semiconductor interface is reviewed. We report on our recent studies of the interface structure in [(Si)_m(Ge)_n]_p superlattices and (Ge)_n layers buried in Si as revealed by Raman scattering, extended X-ray absorption fine structure, and X-ray techniques. Strain relaxation and interdiffusion in the superlattices caused by annealing have been investigated, and it is found that considerable strain-enhanced intermixing together with partial relaxation of Ge-Ge bonds occurs even for very short anneal times at 700°C. Further annealing leads to diffusion at a much slower rate and to the eventual formation of an alloy layer. The Ge-Ge bond lengths in as-grown samples are that expected for a fully strained Ge layer. Similar studies of the (Ge)_n layers reveal that two-dimensional pseudomorphic growth proceeds up to n = 5, probably mediated by a Si-Ge interface interdiffusion over one or two monolayers of approximately 20%. A n = 12 layer gave evidence of strain relaxation by the introduction of dislocations and clustering. Interdiffusion proceeds rapidly on annealing at 750°C.

Recommended Citation

Lockwood, D. J.; Baribeau, J. -M.; Jackman, T. E.; Aebi, P.; Tyliszczak, T.; Hitchcock, A. P.; and Headrick, R. L. (1992) "Influence of Annealing on the Interface Structure and Strain Relief in Si/Ge Heterostructures on (100) Si," Scanning Microscopy: Vol. 7: No. 2, Article 1.
Available at: https://digitalcommons.usu.edu/microscopy/vol7/iss2/1