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Strain and Mosaic Structure in Si0.7Ge0.3 Epilayers Grown on Si (001) Substrates Characterized by High Resolution X-Ray Diffraction

Published online by Cambridge University Press:  10 February 2011

J. H. Li
Affiliation:
Department of Physics, University of Houston, Houston, TX 7096 Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100080, China
S. C. Moss
Affiliation:
Department of Physics, University of Houston, Houston, TX 7096
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Abstract

X-ray double- and triple-axis diffractometries were employed to characterize the strain status and structural deformation in Si0.7Ge0.3 alloy layers grown on Si (001) substrates. We show that, at low levels of strain relaxation, x-ray peaks of the Si0.7Ge0.3 alloy layers contain two components, a narrow one superimposed on a broad one. Such a peak profile corresponds to a layer structure consisting of mosaic regions laterally separated by more perfect regions. With the increase in the degree of strain relaxation and consequently in the dislocation density, the narrow component of the x-ray peak gradually disappears as a result of expansion of the mosaic regions and shrinkage or even vanishing of the perfect regions in the layer. Moreover, our results indicate that the conventional method of estimating dislocation density from the x-ray rocking curve width fails in our case.

Type
Research Article
Copyright
Copyright © Materials Research Society 2000

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References

REFERENCES

1. Hansson, P.O., Werner, J.H., Tapfer, L., Tilly, L.P., and Bauer, E., J. Appl. Phys. 68, 2158 (1990).Google Scholar
2. Houghton, D.C., Perovic, D.D., Baribeau, J.M., and Weatherly, G.C., J. Appl. Phys. 67, 1850 (1990).Google Scholar
3. Gay, P., Hirsch, P.B., and Kelly, A., Acta Met. 1, 315 (1953)Google Scholar
4. Hordon, M.J. and Averbach, B.L., Acta Met. 9, 237 (1961).Google Scholar
5. Ayers, J.E., J. Cryst. Growth 135, 71 (1994).Google Scholar
6. Holy, V., Kubena, J., Abramof, E., Lischka, K., Pesek, A., and Koppensteiner, E., J. Appl. Phys. 74, 1736 (1993).Google Scholar
7. Koppensteiner, E., Schuh, A., Bauer, G., Watson, G.P., and Fitzgerald, E.A., J. Phys. D 28, A114 (1995).Google Scholar
8. For example, see LeGoues, F.K., Meyerson, B.S., and Morar, J.F., Phys. Rev. Lett. 66, 2903 (1991).Google Scholar
9. Mooney, P.M., LeGoues, F.K., Chu, J.O., and Nelson, S.F., Appl. Phys. Lett. 62, 3464 (1993).Google Scholar
10. Li, J.H., Mai, Z.H., Cui, S.F., Zhou, J.M., and Feng, W., Appl. Phys. Lett. 63, 3327 (1993).Google Scholar
11. Li, J.H., Peng, C.S., Wu, Y., Dai, D.Y., Zhou, J.M., and Mai, Z.H., Appl. Phys. Lett. 71, 3132 (1997).Google Scholar
12. Hirth, P. and Lothe, J., Theory ofDislocations (Wiley, New York, 1972).Google Scholar
13. Hohnisch, M., Herzog, H.J., and Schaffler, F., J. Cryst. Growth 157, 126 (1995).Google Scholar