Identification and tackling of a parasitic surface compound in SiC and Si-rich carbide films

► Silicon carbide and silicon rich carbide films are prepared by PECVD. ► Annealing at 1100 °C promotes Si nanocrystal formation in SiC. ► A parasitic SiOxCy compound is formed on the surface during annealing. ► The surface affects optical and electrical properties of the nanocrystal layer. ► We analyze a fabrication sequence that minimizes oxidation. ► The resulting surface is SiC-rich.