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Equilibrium Configuration of Epitaxially Strained Thin Film Surfaces

Published online by Cambridge University Press:  21 February 2011

K. Jagannadham ,
J. Narayan  and
J.P. Hirth
K. Jagannadham
Affiliation:
Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, [email protected].
J. Narayan
Affiliation:
Department of Materials Science and Engineering, North Carolina State University, Raleigh, NC 27695, [email protected].
J.P. Hirth
Affiliation:
Department of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164.
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Abstract

The formation of convex and concave regions on the surface of a strained thin epitaxial film on a thick substrate is analyzed by minimization of energy associated with the configuration. The strain energy change resulting from the formation of undulations is modelled with the strain in the film represented by a continuous distribution of dislocations along the perturbed surface and the interface. A discrete dislocation model is also used when periodic undulations are formed. Results of energy minimization for germanium or germanium-silicon alloy films on silicon substrate illustrate that convex regions tend to grow. On the other hand, convex regions formed to conserve mass in shape changes associated with concave regions become stable with minimum energy under quasi-equilibrium when the mobility of adatoms is low. We have determined the size and radius of curvature of the undulations at minimum energy and conclude that it is favorable to form atomic steps on the surfaces from which dislocation generation and strain relaxation takes place.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 399: Symposium D – Evolution of Epitaxial Structure and Morphology , 1995 , 383
Copyright
Copyright © Materials Research Society 1996

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References

REFERENCES

1 Srolovitz, D. J., Acta Metall., 37, 621 (1989).Google Scholar
2 Gao, H., Int. J. Solids Structures, 28, 703 (1991).Google Scholar
3 Spencer, B. J., Voorhees, P. W., and Davis, S. H., J. Appl. Phys., 73, 4955 (1993).Google Scholar
4 Kamat, S. V. and Hirth, J. P., J. Appl. Phys., 67, 6844 (1990).Google Scholar
5 Jagannadham, K. and Narayan, J., Mat. Sci. Engng., B8, 107 (1991).Google Scholar
6 Jesson, D. E., Pennycook, S. J., Baribeau, J.-M. and Houghton, D. C., Phys. Rev. Lett., 71, 1744 (1993).Google Scholar
7 Hirth, J. P. and Lothe, J., Theory of Dislocations. Ch. 5, p.113, Krieger Publishing Co., Malabar, Florida, 1992.Google Scholar
8 Jagannadham, K and Marcinkowski, M. J., Unified Theory of Fracture. Ch. 18, Trans Tech Publications Ltd, CH-8707 Zurich-Uetikon, Switzerland, 1984.Google Scholar