Hostname: page-component-8448b6f56d-xtgtn Total loading time: 0 Render date: 2024-04-25T06:53:26.197Z Has data issue: false hasContentIssue false

Layer Tilt and Relaxation in InGaAs/GaAs Graded Buffer Layers

Published online by Cambridge University Press:  15 February 2011

K.M. Matney
Affiliation:
University of California, Los Angeles, CA 90095-1595
J.W. Eldredge
Affiliation:
University of California, Los Angeles, CA 90095-1595
M.S. Goorsky
Affiliation:
University of California, Los Angeles, CA 90095-1595
Get access

Abstract

We investigated the effect of substrate inclination and direction on the structural properties of an InGaAs linearly compositionally graded buffer layer with a AlGaAs/InGaAs superlattice grown by molecular beam epitaxy on 2° offcut GaAs substrates. Reciprocal space maps were used to determine the relaxation and tilt of the buffer layer and superlattice with respect to each other and to the substrate. From (004) reciprocal space maps, a linear relationship between tilt and In mole fraction was observed for the buffer layer. This tilt was greatly reduced near the top of the buffer which was found to be completely strained. Interestingly, the tilt along a <110> direction was greater than that observed along the miscut axis. This may be due to the miscut axis not being parallel to a low index plane. Reciprocal space maps of asymmetric diffraction planes were used to determine the relaxation of the buffer layer as a function of In mole fraction. Along a <110> direction in which no tilt was seen in the (004), the majority of the buffer layer was found to be completely relaxed. However, the top of the buffer layer was found to be completely strained, corresponding to a denuded zone observed in cross section transmission electron microscopy.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1 Eldredge, J.W., Matney, K.M., Goorsky, M.S., Chui, H.C., and Harris, J.S., J. Vac. Sci Technol., B 13, 1 (1995).Google Scholar
2 Mooney, P.M., LeGoues, F.K., Tersoff, J., and Chu, J.O., J. Appl. Phys. 75, 3968 (1994).Google Scholar
3 Ayers, J.E., Ghandhi, S.K., and Schowalter, L.J., J. Cryst. Growth 113, 430 (1991).Google Scholar
4 Kavanaugh, K.L., Chang, J.C.P., Chen, J., Fernandez, J.M., and Wieder, H.H., J. Vac. Sci. Technol. B 10, 1820 (1992).Google Scholar
5 Sluis, P. Van der, J. Appl. Cryst. 27, 1015 (1994).Google Scholar
6 Nagai, H., J. Appl. Phys. 45, 3789 (1974).Google Scholar
7 Leiberich, A. and Levkoff, J., J. Vac Sci. Technol. B 8, 422 (1990).Google Scholar
8 Mooney, P.M., LeGoues, F.K., and Jordan-Sweet, J.L., Appl. Phys. Lett. 65 (22), 2845 (1994).Google Scholar
9 Heinke, H.H., Moller, M.O., Hommel, D., Landwehr, G., J. Cryst. Growth, 135, 41 (1994).Google Scholar
10 Lord, S.M., Ph. D. Thesis, Stanford University, 1993.Google Scholar