Methylsilane-derived fragment ions obtained from a Bernas-type ion source were investigated using a low-energy mass-selected ion beam system. Based on mass-energy analyzer measurements, these ions were determined to be H+, H2+, H3+, CH3+, Si+, and SiCH5+. The SiCH5+ ions were selected and injected into a Si(111) substrate at 750 °C. The ion energy was 40 eV. This injection led to the formation of a silicon carbide film on the Si substrate. An analysis of this film indicates that this type of ion beam deposition method can efficiently form silicon carbide film.