Hostname: page-component-78c5997874-j824f Total loading time: 0 Render date: 2024-11-18T08:43:19.275Z Has data issue: false hasContentIssue false
  • English
  • Français

Transition from Schottky Limit to Bardeen Limit in the Schottky Barrier Formation of al on n- and p-GaAs(110) Interfaces

Published online by Cambridge University Press:  26 February 2011

K. K. Chin ,
R. Cao ,
T. Kendelewicz ,
K. Miyano ,
M. D. Williams ,
S. Doniach ,
I. Lindau  and
W. E. Spicer
K. K. Chin
Affiliation:
University of Notre Dame, Dept. of Physics, Notre Dame, IN 46556
R. Cao
Affiliation:
University of Notre Dame, Dept. of Physics, Notre Dame, IN 46556
T. Kendelewicz
Affiliation:
University of Notre Dame, Dept. of Physics, Notre Dame, IN 46556
K. Miyano
Affiliation:
University of Notre Dame, Dept. of Physics, Notre Dame, IN 46556
M. D. Williams
Affiliation:
University of Notre Dame, Dept. of Physics, Notre Dame, IN 46556
S. Doniach
Affiliation:
University of Notre Dame, Dept. of Physics, Notre Dame, IN 46556
I. Lindau
Affiliation:
University of Notre Dame, Dept. of Physics, Notre Dame, IN 46556
W. E. Spicer
Affiliation:
Stanford Electronics Laboratories, Stanford University, Stanford, CA 94305
Get access

Abstract

Schottky barrier formation at room temperature (RT) and low temperature (LT) is studied by photoemission. In the low Al coverage regime (from 0.001 to about 1 ML), it is found that, compared to RT pinning behavior, the n-GaAs(110) surface band bending is attenuated, while the p-GaAs(110) surface band bending is enhanced. This striking phenomenon indicates that, by lowering the substrate temperature, one reduces the disturbance of the GaAs(110) surface, and the surface Fermi level of the n- and p-GaAs(110) tends to go to the same position, the so-called Schottky limit that characterizes a perfect defect-free interface. However, as the coverage increases (up to 30 ML), a new mechanism (in the framework of the unified defect model, it is the formation of defect levels due to the energy released as the adsorbed Al atoms start to form clusters and replace Ga) associated with a disturbed surface becomes dominant. Thus, the LT Fermi level positions of n- and p-GaAs move towards the RT positions, the so-called Bardeen limit. This demonstrates that, by controlling the surface disturbance, one can modify the Schottky barrier formation process, going from the Schottky limit which does not have pinning centers to the Bardeen limit which suggests the existence of pinning centers.

Type
Articles
Information
MRS Online Proceedings Library (OPL) , Volume 77: Symposium D – Interfaces, Superlattices, and Thin Films , 1986 , 297
Copyright
Copyright © Materials Research Society 1987

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. Bardeen, J., Phys. Rev. 71, 717 (1947).CrossRefGoogle Scholar
2. Sze, S. M., Physics of Semiconductor Devices. 2nd ed. (Wiley Interscience, New York, 1981), Ch. 5.Google Scholar
3. Schottky, W., Z. Physik 113, 367 (1939).Google Scholar
4. Huijser, A., van Laar, J., and van Rooy, T. L., Surf. Sci. 62, 472 (1977).Google Scholar
5. Heine, V., Phys. Rev. A 138, 1689 (1965);Google Scholar
Louie, G. and Cohen, M. L., Phys. Rev. B 13, 2461 (1976).Google Scholar
6. Spicer, W. E., Chye, P. W., Skeath, P. R., Su, C. Y., and Lindau, I., J. Vac. Sci. Technol. 16, 1422 (1979);CrossRefGoogle Scholar
Spicer, W. E., Lindau, I., Skeath, P., Su, C. Y., and Chye, P., Phys. Rev. Lett. 44. 420 (1980).Google Scholar
7. Kurtin, S., McGill, T. C., and Mead, C. A., Phys. Rev. Lett. 22, 1433 (1970).Google Scholar
Also see Schlüter, M., Phys. Rev. B 17, 5044 (1978). He found that the previously reported abrupt transition between covalent and ionic semiconductors was not clearly defined and that the outcome was diffused by data scattering.Google Scholar
8. Chin, K. K., Kendelewicz, T., McCants, C., Cao, R., Miyano, C., Lindau, I., and Spicer, W. E., J. Vac. Sci. Technol. A4, 969 (1986).CrossRefGoogle Scholar
9. Kendelewicz, T., Williams, M. D., Chin, K. K., McCants, C., List, R. S., Lindau, I., and Spicer, W. E., Appl. Phys. Lett. 48, 919 (1986).CrossRefGoogle Scholar
10. Skeath, P. R., Ph. D. Dissertation, Stanford University (1982) and references therein.Google Scholar
11. Daniels, R. R., Katnani, A. D., Zhao, T.-X., Margaritondo, G., and Zunger, A., Phys. Rev. Lett. 49, 895 (1982).Google Scholar
12. Bonapace, C. R., Tu, D. W., Li, K., and Kahn, A., J. Vac. Sci. Technol. B3, 1099 (1985).Google Scholar
13. Zunger, A., Phys. Rev. B24, 4372 (1981).Google Scholar
14. Chin, K. K., McKernan, P., and Lindau, I., J. Vac. Sci. Technol. A4 (4), 1949 (1986).Google Scholar
15. Bonapace, C. R., Li, K., and Kahn, A., J. de Phys. Paris 41, C5–409 (1984).Google Scholar
16. Li, K. and Kahn, A., J. Vac. Sci. Technol. A4(3), Part 1, 958 (1986) and references therein.Google Scholar
17. Zur, Z., McGill, T. C., and Smith, D. L., Phys. Rev. B28, 2060 (1983).Google Scholar
18. Spicer, W. E., Pan, S. H., Mo, D., Newman, N., Mahowald, P., Kendelewicz, T., and Eglash, S., J. Vac. Sci. Technol. B2(3), 476 (1984).Google Scholar
19. CRC Handbook of Chemistry and Physics, 67th ed., edited by Weast, R. C. and Astle, M. J. (CRC Press, Boca Raton, Florida, 1986–1987), p. E89.Google Scholar
20. Freeouf, J. L. and Woodall, J. W., Appl. Phys. Lett. 39, 727 (1981).Google Scholar
21. Ludeke, R., Chang, T.-C., and Miller, T., J. Vac. Sci. Technol. B1(3), 581 (1983).Google Scholar
22. Doniach, S., Chin, K. K., Lindau, I., and Spicer, W. E., Phys. Rev. Lett. 58, 591 (1987).Google Scholar