Crystal growth of 3C-SiC on Si(100), (111) substrate was carried out by atmospheric pressure chemical vapor deposition using hexamthyldisilane (Si2(CH3)6:HMDS) and H-2 gas mixtures. Temperature dependence of growth rate and crystallinity of SiC films were examined. The growth process was characterized by a mass spectrometric study of the decomposition of HMDS and H-2 mixtures. Using HMDS as a source material, low temperature epitaxy was realized at a substrate temperature of 1100-degrees-C. With and without a carbonized buffer layer, single-crystal 3C-SiC was grown on Si(111) substrate at the growth rates as high as 701 angstrom/min. With Si(100) as a substrate, single crystals were grown only with a buffer layer.