Dome-like and dense SiC-SiO₂ nanocomposite films synthesized by laser chemical vapor deposition using CO₂ laser

SiC-SiO₂ nanocomposite films were prepared by laser chemical vapor deposition (LCVD) using a CO₂ laser; tetraethyl orthosilicate and acetylene were used as precursors. An amorphous phase was formed at a deposition temperature below 1650K, whereas a SiC (3C) crystalline phase was co-deposited with amorphous SiO₂ at a deposition temperature above 1650K. Dome-like deposits were observed when low total pressure and high temperature were applied. At higher total pressure and lower temperature, the SiC-SiO₂ nanocomposite film was obtained, with SiC grains about 10nm in diameter distributed in amorphous SiO₂. The highest deposition rate was 374μm h^-1 at 1675K and 400Pa.