The initial formation of silicon carbide by the interaction of 1,3-disilabutane (DSB) with a Si(111) surface has been studied in the temperature range of 100-1200 K using the low-energy Cs+ reactive scattering and x-ray photoelectron spectroscopy (XPS). By combining the results of these two techniques, adspecies in the intermediate states during the decomposition of DSB were qualitatively identified and the binding energies and full widths at half maximum of their C(1s) peaks were characterized. At 100 K, 1,3-DSB was found to adsorb on the surface as the C2H8Si2 species as well as CH,Si and to condense molecularly on the monolayer of C2H8Si2 adspecies. XPS indicates that the molecular species desorbs mostly at 200 K and completely at 300 K. Up to 600 K, the C2H8Si2 adspecies are converted to CH4Si with increasing temperature and then above this temperature the CH4Si species decomposes to form the SiC film. The intensity variations of Si(2p) and total C(1s) peaks and the analysis by curve fitting of the C(1s) peaks suggest that one C2H8Si2 adspecies makes only one CH4Si adspecies by breakage of the central C-Si bond rather than two CH4Si adspecies.