Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-19T16:49:38.654Z Has data issue: false hasContentIssue false

The Vibrational Spectrum of a-SiC:H Films in the 500 cm-1 to 9000 cm-1 Range by Ftir Transmission and Photothermal Deflection Spectroscopy

Published online by Cambridge University Press:  21 February 2011

E. Lotter
Affiliation:
Institut für Physikalische Elektronik, Universität Stuttgart, Pfaffenwaldring 47, D-7000 Stuttgart 80, Federal Republic of Germany
G.H. Bauer
Affiliation:
Institut für Physikalische Elektronik, Universität Stuttgart, Pfaffenwaldring 47, D-7000 Stuttgart 80, Federal Republic of Germany
Get access

Abstract

Applying PDS in the energy range from 3000 to 9000 cm-1 considerably improves the sensitivity of vibrational spectroscopy of thin films. In a-SiC:H we have found a large number of absorption features not seen before, which give new insight in structural and compositional properties of these alloys.

In a-SiC:H, in addition to the fundamental and the first and second overtone of C-H stretching modes, O-H vibrations occur at 3500 cm-1 and allow a very sensitive detection of chemical degradation of films due to in-diffusion of water. Combined excitation of C-H stretching and C-H wagging or bending modes give rise to a modified interpretation of the origin of the C-H related absorption features observed in methane based a-SiC:H. The induced absorption of molecular hydrogen together with a band at 7000 cm-1, which results from a combined excitation of C-H bonds and H2 molecules colliding with the C-H, indicates that the amount of H2 increases with C alloying. The C-H + H2 combination mode is very strong compared to the corresponding Si-H + H2 peak observed in pure a-Si:H and signalizes mat a considerable amount of the molecular hydrogen enclosed in voids, containing CH3 or CH2 groups.

Type
Research Article
Copyright
Copyright © Materials Research Society 1992

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. Wieder, H., Cardona, M., and Guamieri, C.R., phys. stat. sol. (b) 92, 99 (1979)CrossRefGoogle Scholar
2. Tawada, Y., Tsuge, K., Kondo, M., Okamoto, H., and Hamakawa, Y., J. Appl. Phys. 53, 5273 (1982).CrossRefGoogle Scholar
3. McKenzie, D.R., J. Phys. D 18, 1935 (1985).CrossRefGoogle Scholar
4. Lotter, E., Schubert, M.B., Heintze, M., and Bauer, G.H. in Amorphous Silicon Technology - 1991, edited by Madan, A., Hamakawa, Y., Thompson, M.J., Taylor, P.C., and LeComber, P.G. (Mater. Res. Soc. Proc. 219, Pittsburgh, PA, 1991) pp. 229234.Google Scholar
5. Chisholm, D.A. and Welsh, H.L., Can. J. Phys. 32, 291 (1954).CrossRefGoogle Scholar
6. Chabal, Y.J. and Patel, C.K.N., Phys. Rev. Lett. 53, 210 (1984).CrossRefGoogle Scholar
7. Halonen, L. and Child, M. S., Mol. Phys. 46, 239 (1982).CrossRefGoogle Scholar
8. An Infrared Spectroscopy Atlas for the Coatings Industry, edited by Vandeberg, J.T., Anderson, D.G., Duffer, J.K., Julian, J.M., Scott, R.W., Sutliff, T.M., and Vaickus, M.J. (Federation of Societies for Coatings Technology, Philadelphia, PA 1980) pp. 34, 289, 293.Google Scholar
9. Bullot, J. and Schmidt, M.P., phys. stat. sol. (b) 143, 345 (1987).CrossRefGoogle Scholar
10. Tawada, Y., Tsuge, K., Kondo, M., Nishimura, K., Okamoto, H., and Hamakawa, Y., Proc. 4th EC PVSEC, edited by Bloss, W.H. and Grassi, G. (Reidei Publishing Company, Dordrecht, Holland, 1982), pp. 698.Google Scholar
11. Manan, A.H., Nelson, B.P., Crandall, R.S., and Williamson, D.L., IEEE Trans. Electron Devices 36, 2859 (1989).CrossRefGoogle Scholar
12. Eberhardt, K., Lotter, E., Heintze, M., Mohring, H.-D. and Bauer, G.H., this Volume.Google Scholar