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Anisotropic Behaviour of Surface Roughening in Lattice Mismatched Heteroepitaxial Thin Films

Published online by Cambridge University Press:  15 February 2011

Cengiz S. Ozkan
Affiliation:
Materials Science and Engineering Department, Stanford University, Stanford, CA 94305
William D. Nix
Affiliation:
Materials Science and Engineering Department, Stanford University, Stanford, CA 94305
Huajian Gao
Affiliation:
Mechanical Engineering Department, Stanford University, Stanford, CA 94305
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Abstract

Heteroepitaxial Si1-xGex. thin films deposited on silicon substrates exhibit surface roughening via surface diffusion under the effect of a compressive stress which is caused by a lattice mismatch. In these films, surface roughening can take place in the form of ridges which can be aligned along <100> or <110> directions, depending on the film thickness. In this paper, we investigate this anisotropic dependence of surface roughening and present an analysis of it. We have studied the surface roughening behaviour of 18% Ge and 22% Ge thin films subjected to controlled annealing experiments. Transmission electron microscopy and atomic force microscopy have been used to study the morphology and microstructure of the surface ridges and the dislocations that form during annealing.

Type
Research Article
Copyright
Copyright © Materials Research Society 1997

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References

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