Nanocrystalline cubic silicon carbide films prepared by hot-wire chemical vapor deposition using SiH4/CH4/H2 at a low substrate temperature

To elucidate the availability of CH4 gas as a carbon source for low-substrate-temperature (325 degrees C) deposition of nanocrystalline SiC films, we investigated the effect of tungsten filament temperature (T-f) with a HW-CVD technique. The film structure changed from amorphous into nanocrystalline cubic SiC (3C-SiC) with increasing T-r from 1400 degrees C to 1600 degrees C. The film prepared at Tf = 1600 degrees C contained not only 3C-SiC nanocrystallites but also amorphous silicon (a-Si) phase. At T-f >= 1700 degrees C, stoichiometric nanocrystalline 3C-SiC films were obtained and did not show a Raman peak due to a-Si but just peaks due to 3C-SiC. It was found that an increase in Tr enhanced the crystallinity of SiC films, and that CH4 was quite useful for preparing nanocrystalline SiC films. (c) 2006 Elsevier B.V. All rights reserved.