Importance of H2 gas for growth of hot-wire CVD nanocrystalline 3C-SiC from SiH4/CH4/H2

Silicon carbide (SiC) thin films were prepared by hot-wire chemical vapor deposition from SiH4/CH4/H2 and the influence of H2 gas flow rate (F(H2)) on the film properties was investigated. The SiH4 gas flow rate was 1 sccm. At the CH4 gas flow rate (F(CH4)) of 1 sccm, nanocrystalline cubic SiC (nc-3C-SiC) grew even without H2. On the other hand, at F(CH4) = 2 sccm, amorphous SiC grew without H2 and nc-3C-SiC grew above F(H2) = 50 sccm. As F(H2) was increased, the crystallinity improved both at F(CH4) = 1 and 2 sccm. However, the mean crystallite size decreased at F(CH4) = 1 sccm and increased at F(CH4) = 2 sccm. We discuss growth mechanisms of nc-3C-SiC.