Temperature-dependent studies of a-SiC:H growth by remote plasma CVD using methylsilanes

摘要

Thin hydrogenated amorphous silicon carbide (a-SiC:H) films were grown at substrate temperatures rangine from 200 K to 600 K by remote ECR plasma-enhanced CVD. Mono-and trimethylsilane were used as single source precursors. The films grown using both precursors were compared as a function of temperature by in situ multiple internal reflection Fourier transform infrared (MIR-FTIR) spectroscopy. The difference in growth temperature leads to changes in both the hydrogen content and the composition of the film. At low growth temperature, films incorporate high concentrations of intact methyl group and a mixture of SiH_2(X chemical bounds 1-3) groups, with a polysilane-like structure. At higher temperatures, the hydrogen content decreases. This decrease is observed in two different ways: (1) a loss of highly hydrogenated SiH_x groups (SiH_3 or SiH_2); and (2) s ahift from methyl groups to CH_2 and CH bonding. However, the temperature dependence of each functional group is found to be different for the two precurosrs.