Substrate-Dependent Growth of Polycrystalline Silicon Films Prepared by Plasma-Enhanced Chemical Vapor Deposition Using SiF 4 and H 2 Gases

Abstract

The growth of polycrystalline silicon films deposited on two different types of substrates by rf plasma-enhanced chemical vapor deposition using SiF4 and H-2 gases was investigated. We observed that on the glass substrates, small grains grew and grain boundaries were not clear at the early stage of deposition (less than or equal to 100 nm) before the growth of a columnar crystalline layer. However, on the SiO2 substrates, alter the growth of a thin amorphous layer (similar to 10 nm), direct growth of a columnar crystalline layer was observed. Surface roughness of the films increases with the film thickness on both substrates and is larger on glass substrate than on SiO2 substrate. The growth mechanism of the poly-Si films deposited on these two types of substrates was also discussed.