Identification of fragment ions produced from hexamethyldisilazane and production of low-energy mass-selected fragment ion beam

Fragment ions produced from hexamethyldisilazane (HMDS) with a hot tungsten wire in a Freeman-type ion source were assayed using a low-energy mass-selected ion beam system. The possible candidates of chemical formulae for these ions are C+, N+, CH3+, CH4+, Si+, SiCH5+, SiC2H6+, SiC3H9+, Si2NCH4+, Si2NC2H7+, Si2NC3H10+, Si2NC4H12+, and Si2NC5H16+. The ion production strongly depended on the tungsten temperature. Among the HMDS derived fragment ions, SiCH5+ ions were mass-selected. The ion energy was 100 eV. Then, the SiCH5+ ions were irradiated to a Si substrate. It was inferred from the analysis of resulting deposited film that silicon carbide films containing a small amount of nitrogen atoms were deposited following the irradiation.