Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-27T02:36:20.844Z Has data issue: false hasContentIssue false

Microcrystallinity in a-Si & a-SiC Films Made by Hg-Sensitized Photo-CVD

Published online by Cambridge University Press:  25 February 2011

N. Saxena
Affiliation:
Institute of Energy Conversion, University of Delaware, Newark, DE-19716.
C. M. Fortmann
Affiliation:
Institute of Energy Conversion, University of Delaware, Newark, DE-19716.
T. W. F. Russell
Affiliation:
Institute of Energy Conversion, University of Delaware, Newark, DE-19716.
Get access

Abstract

A model for the role of H atoms as an etchant specie during deposition of microcrystalline (μc) films of Si:H and SiC:H is explored. Growth rates and etch rates of films made by Hg-sensitized photo-CVD have been measured as a function of reactor pressure (between 5 and 0.5 torr) and H2 dilution (up to 30:1). Gas phase reactions and diffusion to the substrate of depositing and etching species, have been modelled. It is found that high H radical flux (not necessarily high H2 dilution) promotes μc film growth. There are two surface etching reactions by H radicals: (i) selective etching of uncoordinated Si surface atoms (amorphous phase) from the film, leaving behind the more etch-resistant μc phase; (ii) in SiC:H alloy systems, a selective etching of C species, causing a decrease in C incorporation into the growing microcrystalline film. Films with increasing carbon content do not contain a μc-SiC phase because hydrogen is not eliminated from the carbon containing film precursors, thus inhibiting the development of crystalline Si-C network.

Type
Research Article
Copyright
Copyright © Materials Research Society 1989

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. Hattori, Y., Kruangam, D., Toyama, T., Okamoto, H. and Hamakawa, Y., Tech. Dig. Intl. PVSEC-3 Tokyo, Japan, 1987,171–174Google Scholar
2. Veprek, S., Heintze, M., Sarott, F. A., Jurcik-Rajman, M. and Willmott, P., Symp. Proc. 118, 1988, 3 CrossRefGoogle Scholar
3. Matsuda, A., J. Non-Cryst. Sol., 59&60 (1983), 763774 Google Scholar
4. Dalal, V. L., Fortmann, C. M. and Eser, E., AIP Conf. Proc., 73(1981),1519 CrossRefGoogle Scholar
5. Rocheleau, R. E., Hegedus, S. S., Buchanan, W. A. and Jackson, S. C., Appl. Phys. Lett., 51(2)(1987), 133 CrossRefGoogle Scholar
6. Perrin, J. & Broekhuizen, T., MRS Symp. Proc. 75, 1987, 201208 CrossRefGoogle Scholar
7. Goldstein, B., Dickson, C.R., Campbell, I. H. and Fauchet, P.M., Appl. Phys. Lett., 53(21)(1988), 2672–4CrossRefGoogle Scholar
8. Morimoto, A., Miura, T., Kumeda, M. and Shimizu, T., J. Appl. Phys., 53(11), 1982, 7299–305CrossRefGoogle Scholar