Film properties of nanocrystalline 3C-SiC thin films deposited on glass substrates by hot-wire chemical vapor deposition using CH4 as a carbon source

Nanocrystalline cubic silicon carbide (3C-SiC) thin films have been successfully prepared on glass substrates (at a low temperature of around 325 degrees C) by hot-wire chemical vapor deposition using CH4 as a carbon source. It was found that using CH4, i.e., a SiH4/CH4/H-2 system, is useful for the low-temperature deposition of nanocrystalline 3C-SiC thin films and that filament temperature (T-f) is a significant parameter. The structural transition from hydrogenated amorphous SiC (a-SiC:H) to nanocrystailine 3C-SiC occurred with increasing T-f from 1400 to 1600 degrees C. The mean crystallite size of the obtained films was 2.6 to 8.4 nm. The IR absorption peak due to Si-C bonds showed a single Lorentzian shape, and with increasing Tf, intensity increased and full width at half maximum decreased. This indicates that the crystallinity of 3C-SiC was improved. The SiH4/CH4/H-2 system has enabled us to prepare nanocrystalline 3C-SiC thin films at a low H-2 dilution ratio in comparison with the findings of other groups obtained thus far, resulting in a high deposition rate of over 0.15 nm/s.