Hostname: page-component-848d4c4894-xfwgj Total loading time: 0 Render date: 2024-07-07T07:18:15.287Z Has data issue: false hasContentIssue false

Hydrogen incorporation mechanisms in the preparation of a-Si:H by ion bombardment-activated reactive evaporation

Published online by Cambridge University Press:  31 January 2011

H. Strauven
Affiliation:
Departement Natuurkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3030, Leuven, Belgium
A. Stesmans
Affiliation:
Departement Natuurkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3030, Leuven, Belgium
J. Winters
Affiliation:
Departement Natuurkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3030, Leuven, Belgium
J. Spinnewijn
Affiliation:
Departement Natuurkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3030, Leuven, Belgium
O. B. Verbeke
Affiliation:
Departement Natuurkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200 D, B-3030, Leuven, Belgium
Get access

Abstract

Here a-Si:H is prepared by ion bombardment-activated reactive evaporation of Si in a H2O residual gas pressure ranging from 10−9 to 10−7 Torr. The Si+ ions (2.7keV) are bombarding the substrate and the walls during evaporation. Two hydrogen incorporation mechanisms are revealed by H evolution experiments, depending on the H2O residual gas pressure during evaporation. In the first mechanism H is sputtered from the walls of the system by the ion bombardment; this mechanism contributes 10 at. % to the hydrogen content. In a second mechanism Si+ bombardment on the growing layer injects H from H2O molecules adsorbed on the film surface; at least 5 at. % H is incorporated by this process. The second mechanism has a remarkable influence on the microstructure as revealed from the electrical conductivity, electron spin resonance, and infrared transmission. Indeed, Si+ bombardment-induced injection of H changes the conductivity type from variable range hopping to an activated behavior, while the dangling bond density remains low (< 1018 cm −3). The growth of [SiH2]n bundles, observed by the resonance frequency and absorption strength of the stretch mode of the Si–H dipole, is also a consequence of the H injection mechanism. It is concluded that the properties of the a-Si:H, prepared by ion bombardment-activated reactive evaporation, are explained by a microstructure, dependent on the specific hydrogen incorporation mechanism.

Type
Articles
Copyright
Copyright © Materials Research Society 1988

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

1Spear, W. E. and Comber, P. G. Le, in The Physics of Hydrogenated Amorphous Silicon I, Topics in Applied Physics, edited by Joannopoulos, J. D. and Lucovsky, G. (Springer, New York, 1984), Vol. 55, p. 90.Google Scholar
2Voget-Grote, U., Kiimmerle, W., Fisher, R., and Stuke, J., Philos. Mag. B 41, 127 (1980).Google Scholar
3Strauven, H., Stesmans, A., Winters, J., Spinnewijn, J., and Verbeke, O. B., J. Appl. Phys. 62, 2836 (1987).Google Scholar
4Strauven, H., Wijngaerdt, E. De, Spinnewijn, J., and Verbeke, O. B., Rev. Sci. Instrum. 58, 313 (1987).CrossRefGoogle Scholar
5Tavendale, A. J., Alexiev, D., and Williams, A. A., Appl. Phys. Lett. 47, 316 (1985).Google Scholar
6Brodsky, M. H., Cardona, M., and Cuomo, J. J., Phys. Rev. B16, 3556 (1977).Google Scholar
7Brodsky, M. H. and Title, R. S., Phys. Rev. Lett. 23, 581 (1969).CrossRefGoogle Scholar
8Nagels, P., in Amorphous Semiconductors, Topics in Applied Physics, edited by Brodsky, M. H. (Springer, New York, 1979), Vol. 36, p.113.CrossRefGoogle Scholar
9Pollard, W. B. and Lucovsky, G., Phys. Rev. B 26, 3172 (1982).Google Scholar
10Shanks, H., Fang, C. J., Ley, L., Cardona, M., Demond, F. J., and Kalbitzer, S., Phys. Status Solidi B 100, 43 (1980).Google Scholar
11John, P., Odeh, I. M., Thomas, M. J. K., Tricker, M. J., and Wilson, J. I. B., Phys. Status Solidi B 105, 499 (1981).Google Scholar
12Lucovsky, G., Solid State Commun. 29, 571 (1978).Google Scholar
13Knights, J. C. in Ref. l, p. 43.Google Scholar
14Oguz, S. and Paesler, M.A., Phys. Rev. B 22, 6213 (1980).Google Scholar
15Biegelsen, D. K., Street, R. A., Tsai, C. C., and Knights, J. C., Phys. Rev. B 20, 4839 (1979).CrossRefGoogle Scholar
16Kittel, C., Introduction to Solid State Physics (Wiley, New York, 1976), p. 406.Google Scholar
17Cardona, M., Phys. Status Solidi B 118, 463 (1983).Google Scholar
18Phillips, J. C., J. Appl. Phys. 59, 383 (1986).CrossRefGoogle Scholar
19We have used TRIM-85 for the Monte Carlo simulations; Ziegler, J. F., Biersack, J. P., and Littmark, U., in The Stopping and Ranges of Ions in Matter I, edited by Ziegler, J. F. (Pergamon, New York, 1985), p. 232.Google Scholar
20Brodie, D. E. and Moore, C. J. L., Can. J. Phys. 62, 898 (1984).Google Scholar
21Audas, R., Brodie, D. E., Cowan, J. A., and Moore, C. J. L., Can. J. Phys. 64, 16 (1986).Google Scholar
22Seager, C. H., Anderson, R. A., and Panitz, J. K. G., J. Mater. Res. 2, 96 (1987).Google Scholar
23Suzuki, M., Suzuki, M., Kanada, M., and Kakimoto, Y., Jpn. J. Appl. Phys. 21, L89 (1982).Google Scholar