The deposition of silicon carbide thin film on Si (100) wafer, using low pressure CVD of SiH 2 Cl 2 /C 2 H 2 /H 2 reaction system, is investigated. The SiC film deposited at 1023K is amorphous, 1073K is microcrystalline, and 1173K is (110) preferentially oriented. The deposition rate increases significantly with temperature. Deposition kinetics of surface and gas-phase paths is separated by varying the volume/surface ratio of deposition environment. The activation energy for gas-phase reaction path is estimated to be 76kcal/mol, and that for surface reaction path is 71kcal/mol. The experimental barrier for gas-phase reaction path is close to the values by ab initio calculation (Su and Schlegel), which range from 73 to 76kcal/mol for the step of H 2 elimination from SiH 2 Cl 2 .