Hydrogenated amorphous silicon-germanium (a-SiGe:H) alloys have been attracting much attention in application to solar cells. Plasma CVD technique is widely used to deposit the a-SiGe films. Thus it is very important to understand the relationship among the film deposition conditions, the properties of films and the plasma parameters. In this study, SiH
4-GeH
4-H
2 mixture gases were decomposed in a parallel plane electrode system with 13.56MHz radio frequency glow discharges. The plasma parameters such as electron temperature and density were measured by floating double probe method. We studied a-SiGe films with an optical gap of 1.6eV, and the following results were obtained:
a) Substrate temperature is the most important deposition parameter to improve the quality of a-SiGe film.
b) Plasma parameters affect the film deposition rate, but influence on film quality is not large.
c) "Ion damage" is small under the deposition conditions for obtaining device-grade a-SiGe films.
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