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 325 degrees C 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 = 1400 degrees C was amorphous SiC:H and that films prepared at Tf above 1600 degrees C 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.