Preparation of Nanocrystalline Silicon Carbide Thin Films by Hot-Wire Chemical Vapor Deposition at Various Filament Temperature

We prepared silicon carbide (SiC) thin films by hot-wire chemical vapor deposition (HW-CVD) using methane as a carbon source gas at substrate temperature of 325degC and investigated the influence of filament temperature, T
_f
, on the structure and optical properties of the resulting films. X-ray diffraction patterns showed that film prepared at T
_f
=1400degC was amorphous SiC:H and that films prepared at T
_f
above 1600degC were nanocrystalline 3C-SiC. In addition, as the T
_f
was increased, the mean crystallite size and XRD peak intensity increased. The optical absorption spectra shifted toward higher energy region with increasing T
_f
, suggesting the band gap became higher. It was found that nanocrystalline 3C-SiC could be obtained from HW-CVD using methane source gas even at a low substrate temperature