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

Abstract

To elucidate the availability of CH4 gas as a carbon source for low-substrate-temperature (325°C) deposition of nanocrystalline SiC films, we investigated the effect of tungsten filament temperature (Tf) with a HW-CVD technique. The film structure changed from amorphous into nanocrystalline cubic SiC (3C–SiC) with increasing Tf from 1400°C to 1600°C. The film prepared at Tf=1600°C contained not only 3C–SiC nanocrystallites but also amorphous silicon (a-Si) phase. At Tf⩾1700°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 Tf enhanced the crystallinity of SiC films, and that CH4 was quite useful for preparing nanocrystalline SiC films.