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Double Crystal X-Ray Diffraction Measurement of a Triclinicly Distorted and Tilted AlxGa1-xAs Unit Cell Produced by Growth on Offcut GaAs Substrates

Published online by Cambridge University Press:  25 February 2011

A. Leiberich  and
J. Levkoff
A. Leiberich
Affiliation:
AT&T Bell Laboratories, Engineering Research Center, Princeton, NJ. 08540
J. Levkoff
Affiliation:
AT&T Bell Laboratories, Engineering Research Center, Princeton, NJ. 08540
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Abstract

Corrections are required for double crystal X-ray diffraction characterization of epitaxial AlxGa1-xAs layers grown on offcut GaAs (100) substrates. Double crystal X-ray diffraction measurements show that the cubic film unit cell defined by Vegard's law is triclinicly distorted and tilted with respect to the substrate unit cell. The distortion and tilt angles oppose each other defining a crystal geometry where the substrate and film <100= axes remain approximately coplanar with the surface normal. This film/substrate crystal geometry leads to formulation of a model describing heteroepitaxy on offcut (100) substrates. When film atoms are bonded to an offcut substrate, the already tetragonaly distorted film unit cell is subjected to additional cell distortions. The magnitude of this additional strain depends on where the film atoms are positioned on a substrate terrace. The first few layers of film atoms establish swain grades across individual substrate terraces. Constrained by the geometry of this interface region and driven by strain relaxation in the net growth direction, subsequent heteroepitaxy forms the measured film/substrate crystal geometry.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 159: Symposium C – Atomic Scale Structure of Interfaces , 1989 , 101
Copyright
Copyright © Materials Research Society 1990

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References

REFERENCES

[1] Fukui, T. and Saito, H., J. Vac. Sci. Technol. B6(4), 1373 (1988).Google Scholar
[2] Auvray, P., Baudet, M. and Regreny, A., Workbook of the Fifth Int'l Conf. on MBE (1988), p. 403; J. Cryst. Growth, 95, 288 (1989).Google Scholar
[3] Wada, K., Kozen, A., Fushimi, H. and Inoue, N., J. Cryst. Growth 93, 935 (1988).Google Scholar
[4] Bartels, W.J. and Nijman, W., J. Cryst. Growth 44, 518 (1978).Google Scholar
[5] Book of SEMI Standards, Vol. 3 (Semiconductor Equipment and Materials Institute, Mountain View, CA, 1986).Google Scholar
[6] Levkoff, J. and Leiberich, A., J. Appl. Phys., submitted for publication.Google Scholar
[7] Compton, A.H. and Allison, S.K., X-rays in Theory and Experiment (New York, D. Van Nostrand, 1935).Google Scholar
[8] Macrander, A.T., Schwartz, G.P. and Gualtieri, G.J., J. of the Electrochem. Soc. 134 (9), 578 C (1987).Google Scholar
[9] Ibers, J.A. and Hamilton, W.C., eds., Int'l Tables for X-ray Crystallography, Vol. IV (Kynoch, Birmingham, England, 1974).Google Scholar
[10] Estop, E., Izrael, A. and Sauvage, M., Acta. Cryst. A32, 627 (1976).Google Scholar
[11] Rozgonyi, G.A., Petroff, P.M. and Panish, M.B., J. Cryst. Growth 27, 106 (1974).Google Scholar
[12] Xiong, F., Tombrello, T.A., Chen, H.Z., Morkoc, H. and Yarin, A., J. Vac. Sci. Technol. B6, 2 (1988).Google Scholar
[13] Cullity, B.D., Elements of X-ray Diffraction, 2nd ed. (Addison-Wesley, Reading, MA, 1978).Google Scholar
[14] Leiberich, A. and Levkoff, J., J. Vac. Sci. Technol., submitted for publication.Google Scholar