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Heterojunction Ohmic Contacts to Si Using Ge/Si n+/n+ Structures

Published online by Cambridge University Press:  26 February 2011

M. J. Hafich
Affiliation:
Colorado State University, Fort Collins, CO 80523
R. L. Gillenwater
Affiliation:
Colorado State University, Fort Collins, CO 80523
G. Y. Robinson
Affiliation:
Colorado State University, Fort Collins, CO 80523
P. Sheldon
Affiliation:
Solar Energy Research Institute, Golden, CO 80401
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Abstract

Ohmic contacts to n-type Si have been formed using a thin n layer of Ge grown by selective-area molecular beam epitaxy. The n+Ge is used to lower the metal-semiconductor barrier energy and thus reduce the contact resistivity of the thin film structure. Al/n+Ge/n+Si test devices were fabricated in a manner compatible with conventional VLSI processing and consisted of a 3500 A thick layer of arsenic-doped Ge grown at 250°C on a selectively diffused, phosphorus-doped Si substrate. Using both four terminal Kelvin and transmission line devices, unsintered Al/Ge/Si structures exhibited contact resistivities a factor of five lower than Al/Si control devices, in agreement with theoretical calculations based on a simple tunneling model for the metal/Ge/Si heterojunction ohmic contact.

Type
Research Article
Copyright
Copyright © Materials Research Society 1986

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References

REFERENCES

[1] Chen, J. Y. and Rensch, D. B., IEEE Trans. Electron. Devices, ED–30, 1542 (1983).Google Scholar
[2] Wang, P. D., Selvin, E., and Robinson, G. Y., J. Vac. Sci. Technol., B2, 209 (1984).Google Scholar
[3] Stall, R. A., Wood, C.E.C., Board, K., Dandekar, N., Eastman, L. F., and Delvin, J., J. Appl. Phys. 52, 4062 (1981);Google Scholar
Woodall, J. M., Freeouf, J. L., Pettit, G. D., Jackson, T., and Kirchner, P., J. Vac. Sc. Technol. 19 626 (1981).Google Scholar
[4] Padovani, F. A. and Stratton, R., Solid State Electronics 9, 695 (1966).Google Scholar
[5] Katnani, A. D. and Margaritondo, G., J. Appl. Phys. 54, 2522 (1983);Google Scholar
Mahowald, P. H., List, R. S., Spicer, W. E., Woicik, J., and Pianetta, P., J. Vac. Sc. Technol. B3(4) 1252 (1985).Google Scholar
[6] Tansley, T. L., in Semiconductors and Semi metals, edited by Willardson, R. K. R. K. and Beer, A. C. (Academic Press, New York, 1971).Google Scholar
[7] Proctor, S. J., Linholm, L. W. and Mazer, J. A., IEEE Trans. Electron Devices ED–30 1535 (1983).Google Scholar
[8] Sheldon, P., Yacobi, B. G. and Jones, K. M., presented at the American Vacuum Society 32nd National Symposium, Houston, Texas, Nov. 19–22, 1985.Google Scholar