Hostname: page-component-78c5997874-xbtfd Total loading time: 0 Render date: 2024-11-20T00:30:24.642Z Has data issue: false hasContentIssue false

Optical Characteristics of Amorphous III-V Nitride Thin Films

Published online by Cambridge University Press:  01 February 2011

Jebreel M. Khoshman
Affiliation:
Department of Physics & Astronomy, Condensed Matter & Surface Science Program, Ohio University, Athens, OH 45701
Martin E. Kordesch
Affiliation:
Department of Physics & Astronomy, Condensed Matter & Surface Science Program, Ohio University, Athens, OH 45701
Get access

Abstract

The optical constants and polarized optical properties of amorphous III-V nitride thin films, a-(Al, Ga, In) N, deposited by RF magnetron sputtering onto crystalline silicon, c-Si, (111) and glass substrates have been investigated over the wavelength range 300 – 1400 nm. The optical constants of a-AlN were obtained by analysis of the measured ellipsometric spectra through the Cauchy–Urbach model while the optical constants of a-(In, Ga) N were determined using the Tauc-Lorentz model. Analysis of the absorption coefficient of a-AlN (in the range 200 – 1400 nm) and a-GaN (in the range 300 – 1400 nm) show the optical bandgap to be 5.9 ± 0.05 and 3.44 ± 0.05 eV. The absorption coefficient of a-InN (in the range 300 – 1400 nm) as a function of photon energy shows the absorption edge to be about 1.74 ± 0.05 eV. From the angle dependence of the p-polarized reflectivity we deduced Brewster and principal angles of these films. Measurement of the polarized optical properties revealed a high transmissivity (70 % – 95 %) and low absorptivity (< 18 %) for all three thin films in the visible and near infrared regions.

Type
Research Article
Copyright
Copyright © Materials Research Society 2005

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. Woollam, J. A., Johs, B., Herzinger, C. M., Hilfiker, J., Synowicki, R., and Bungay, C. L., Critical Reviews CR 72, 3 (1999).Google Scholar
2. Richardson, H. H., Van Patten, P. G., Richardson, D. R., and Kordesch, M. E., Appl. Phys. Lett. 80, 2207 (2002).Google Scholar
3. Azzam, R. M. and Bashara, N. M., Ellipsometry and Polarized Light, (North-Holland Publishing, New York, 1983).Google Scholar
4. Herzinger, C. M., Johs, B., McGahan, W. A., Woollam, J. A., and Paulson, W., J. Appl. Phys. 83, 3323 (1998).Google Scholar
5. Gurumurugan, K., Chen, Hong, Harp, G. R., Jadwisienczak, W. M., and Lozykowski, H. J., Appl. Phys. Lett. 74, 3008 (1999).Google Scholar
6. Capan, R., Chaure, N. B., Hassan, A. K., and Ray, A. K., Semicond. Sci. Technol. 19, 198 (2004).Google Scholar
7. Forouhi, A. R. and Bloomer, I., Phys. Rev. B 34, 7018 (1986).Google Scholar
8. Jellison, G. E. and Modine, F. A., Appl. Phys. Lett. 69, 371 (1996).Google Scholar
9. Mohammad, S. N. and Morkoc, H., Progress in Quantum Electronics 20, 5 and 6 (1996).Google Scholar
10. Jellison, G. E., Modine, F. A., Doshi, P., and Rohatgi, A., Thin Solid Films 313–314, 193 (1998).Google Scholar
11. Ikuta, K., Inoue, Y., and Takai, O., Thin Solid Films 334, 49 (1998).Google Scholar
12. Chen, H., Chen, K., Drabold, D. A., and Kordesch, M. E., Appl. Phys. Lett. 77, 1117 (2000).Google Scholar
13. Cody, G. D., Tiedje, T., Abeles, B., Brooks, B., and Goldstein, Y., Phys. Rev. Lett. 47, 1480 (1981).Google Scholar