Hostname: page-component-848d4c4894-m9kch Total loading time: 0 Render date: 2024-06-02T00:36:05.247Z Has data issue: false hasContentIssue false

Comparison of VHF, RF and Dc Plasma Excitation for a-Si:H Deposition with Hydrogen Dilution

Published online by Cambridge University Press:  10 February 2011

R. Platz
Affiliation:
Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA
C. Hof
Affiliation:
Institut de Microtechnique, Université de Neuchâtel, Switzerland
S. Wieder
Affiliation:
Institut für Schicht- und Ionentechnik - PV, Forschungszentrum Jülich, Germany
B. Rech
Affiliation:
Institut für Schicht- und Ionentechnik - PV, Forschungszentrum Jülich, Germany
D. Fischer
Affiliation:
Institut de Microtechnique, Université de Neuchâtel, Switzerland
A. Shah
Affiliation:
Institut de Microtechnique, Université de Neuchâtel, Switzerland
A. Payne
Affiliation:
Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA
S. Wagner
Affiliation:
Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA
Get access

Abstract

A comparative study of DC, RF and VHF excitation for the plasma enhanced chemical vapor deposition (PECVD) of intrinsic layers of a-Si:H is presented, with special emphasis on the effects of hydrogen dilution. Growth rates at comparable plasma power, for substrate temperatures between 100°C and 300°C and for various H2 dilution ratios are presented, along with optical bandgap, H content, and electronic transport properties in the light-soaked state.

H2 strongly reduces the growth rate for all techniques. The growth rate for the highest H2 dilution ratio is approximately four times higher for VHF than for DC or RF excitation. In all three cases increasing the substrate temperature reduces the optical gap and the H content CH. Raising the substrate temperature slightly enhances the stability of undiluted films. H2 dilution increases the optical gap for all three techniques. The H content of RF- and VHF-deposited samples increases with increasing H2 dilution ratio, while in DC deposition it produces an initial drop of the H content, followed by an increase.

In all three cases, H2 dilution improves the electronic transport properties of the material by roughly a factor of two. The gain in stability is most pronounced for relatively small dilution; in the case of DC deposition, too strong a dilution even has an adverse effect on stability.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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 Guha, S., Narasimhan, K.L. and Pietruszko, S.M., J. Appl. Phys. 52 (1981) 859.Google Scholar
2 Guha, S., Proc. 25th IEEE PVSC (1996) 1017.Google Scholar
3 Rech, B., Wieder, S., Siebke, F., Beneking, C., Wagner, H., MRS Symp. Proc. 420 (1996) 33.Google Scholar
4 Platz, R., Fischer, D., Dubail, S. and Shah, A., Solar Energy Materials and Solar Cells 46 (1997) 157.Google Scholar
5 Yang, L., Bennett, M., Chen, L., Jansen, K., Kessler, J., Li, Y., Newtown, J., Rajan, K., Willing, F., Arya, R., Carlson, D., MRS Symp. Proc. 420 (1996) 839.Google Scholar
6 Hof, C., Ziegler, Y., Platz, R., Wyrsch, N. and Shah, A., Proc. ICAMS-7 (Budapest 1997), in print.Google Scholar
7 Beck, N., Wyrsch, N., Hof, C. and Shah, A., J. Appl. Phys. 79 (1996) 9361.Google Scholar
8 Kamins, T.I., Polycrystalline silicon for integrated circuit applications, Kluwer Academic Publishers 1988, p.68.Google Scholar
9 Bennett, M., Rajan, K., Kritikson, K., Proc. 23rd IEEE PVSC (1993) 845.Google Scholar
10 Platz, R., Meier, J., Fischer, D., Dubail, S., Shah, A., MRS Symp. Proc. 467 (1997) 699.Google Scholar
11 Platz, R., Hof, C., Fischer, D., Meier, J., Shah, A., Solar Energy Materials and Solar Cells, in print.Google Scholar