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Surface Reconstruction and Strain Relief in Si1−x-Gex Films on Si(100)

Published online by Cambridge University Press:  25 February 2011

Qiuming Yu  and
Paulette Clancy
Qiuming Yu
Affiliation:
School of Chemical Engineering, Cornell University, Ithaca, NY 14853
Paulette Clancy
Affiliation:
School of Chemical Engineering, Cornell University, Ithaca, NY 14853
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Abstract

The equilibrium structure of a variety of Si1−xGex/Si heterostructures have been simulated by Molecular Dynamics, modeled by the Stillinger-Weber potential, to investigate the effect of strain on the surfaces of SiGe thin Alms. It was found that the strain in SiGe/Si(100) thin films was relaxed by the segregation of Ge to the surface. Rebonding of sub-surface atoms into dimers in the presence of a vacancy or cluster of vacancies above them was observed in the ensuing surface reconstruction. For SiGe/Si, the amount of “re-bonded missing dimers” in the top two layers increased with increasing Ge composition. But for Ge/Si(100), a V-shaped twinning defect was observed in the Ge thin film. To further investigate the effect of strain on surface reconstruction, bulk Si and Ge structures were also studied. For bulk Si, several rebonded missing dimers were found at the surface, while for bulk Ge(100), the surface showed a typical 2×1 reconstruction. All these findings corroborate recent experimental studies and theoretical predictions.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 280: Symposium B – Evolution of Surface and Thin Film Microstructure , 1992 , 725
Copyright
Copyright © Materials Research Society 1993

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References

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