Formation of Silicon Nitride Layer on Microcrystalline Silicon Thin Films by Hot-wire Chemical Vapor Method using Nitrogen and Hydrogen Gases

Abstract

Right after the deposition of hydrogenated microcrystalline silicon (μc-Si:H) thin films, a post-deposition treatment was carried out using the hot-wire chemical vapor technique in N2/H2 atmosphere, to form a nitride layer in the film surface region. The influence of the gas pressure during the post-deposition treatment on the nitride layer formation was investigated. Nitriding at the surface was negligible at 0.1 Torr but was enhanced dramatically with an increase in the gas pressure from 0.1 to 1.0 Torr. Consequently, the surface was almost completely covered with the nitride layer. However, the density of N atoms at the surface reduced with increasing gas pressure from 1.0 to 6.0 Torr. On the other hand, the nitriding on the inside of the films (a depth of 20 nm from the surface) was enhanced by the increase in the gas pressure.