In order to investigate the effect of the supply of hydrogen radicals during the SiC growth, SiC films were grown on Si substrates by low-pressure thermal CVD (LPCVD) and triode plasma CVD using dimethylsilane (DMS). Activation energy for the epitaxial growth rate of SiC by LPCVD was estimated to be 73+/-5kcal/mol, whereas that by triode plasma CVD was about 48+/-2kcal/mol. As in the case of the growth rate of SiC using monomethylsilane (MMS), the activation energy by using the triode plasma CVD was reduced about 25kcal/mol in the case of DMS.