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An Expanding Thermal Plasma for Deposition of a-Si:H

Published online by Cambridge University Press:  15 February 2011

R. J. Severens
Affiliation:
Department of Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
G. J. H. Brussaard
Affiliation:
Department of Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
H. J. M. Verhoeven
Affiliation:
Department of Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
M. C. M. Van de Sanden
Affiliation:
Department of Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
D. C. Schram
Affiliation:
Department of Physics, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands
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Abstract

A remote argon/hydrogen plasma is used to deposit amorphous hydrogenated silicon. The plasma is generated in a DC thermal arc (typical operating conditions 0.5 bar, 5 kW) and expands into a low pressure chamber (20 Pa) thus creating a plasma jet with a typical flow velocity of 103 m/s. Pure silane is injected into the jet immediately after the nozzle, in a typical flow mixture of Ar:H2:SiH4=55:10:6 scc/s. The electron temperature in the jet is low (typ. 0.3 eV) : silane radicals are thought to be produced mainly by hydrogen abstraction, but also by a sequence of dissociative charge exchange and consecutive dissociative recombination. In-situ ellipsometry yields refractive indices of 3.6–4.2 at 632.8 nm and growth rates of 10–20 nm/s. FTIR analysis yields a hydrogen content of 9–25 at.% and refractive indices of 2.7–3.3 in the infrared. The SiH density decreases with increasing hydrogen content, whereas the SiH2 density increases. Above 11 at.%, the majority of hydrogen is bonded in the SiH2 configuration. The optical bandgap remains constant at approximately 1.72 eV. The photoconductivity is of the order 101–6 (Ωcm) 1–6 and the photoresponse 106.

Type
Research Article
Copyright
Copyright © Materials Research Society 1995

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References

REFERENCES

1. Ichikawa, Y., Tabuchi, K., Kato, S., Takano, A., Sasaki, T., Tanda, M., Saito, S., Sato, H., Fujikake, S., Yoshida, T. and Sakai, H., Proc. 1st World Conference on Photovoltaic Energy Conversion, Waikoloa, Hawaii (1994)Google Scholar
2. Ganguly, G. and Matsuda, A., Jpn. J. Appl. Phys. 31, 1269 (1992), J. Non-Cryst. Solids 164–166, 31 (1993)Google Scholar
3. Kroesen, G.M.W., Schram, D.C. and van de Sande, M.J.F., Plasma Chem. and Plasma Proc. 10 (1) 49 (1990)Google Scholar
4. Lucovsky, G., Richard, P.D., Tsu, D.V., Lin, S.Y. and Markunas, R.J., J. Vac. Sci. Technol. A43, 681 (1986)Google Scholar
5. Parsons, G.N., Tsu, D.V. and Lucovsky, G., J. Non-Cryst. Solids 97–98, 1375 (1987)Google Scholar
6. Johnson, N.M., Walker, J., Doland, C.M., Winer, K. and Street, R.A., Appl. Phys. Lett. 54 (19) 1872 (1989)Google Scholar
7. Johnson, N.M., Santos, P.V., Nebel, C.E., Jackson, W.B., Street, R.A., Stevens, K.S. and Walker, J., J. Non-Cryst. Solids 137–138 235 (1991)Google Scholar
8. van de Sanden, M.C.M., de Regt, J.M. and Schram, D.C., Phys. Rev. E 47 2792 (1993)Google Scholar
9. Kushner, M.J., J. Appl. Phys. 63 (8) 2532 (1988)Google Scholar
10. Meulenbroeks, R.F.G., van Beek, A.J., van Helvoort, A.J.G., van de Sanden, M.C.M. and Schram, D.C., Phys. Rev. E 49 4397 (1994)Google Scholar
11. Langford, A.A., Fleet, M.L., Nelson, B.P., Lanford, W.A. and Maley, N., Phys. Rev. B 45 (23) 13367 (1992)Google Scholar
12. Ready, S.E., Joyce, J.B., Johnson, N.M., Walker, J. and Stevens, K.S., Mat. Res. Soc. Symp. Proc. 192 (1990)Google Scholar
13. Turban, G., Catherine, Y. and Grolleau, B., Thin Solid Films 77, 287 (1981)Google Scholar
14. Guha, S., Xu, X., Yang, J. and Banerjee, A., see elsewhere in these proceedingsGoogle Scholar