The kinetics of SiC deposition has been studied over the temperature range 650–1050 ° C using the single-source reagents silacyclobutane (SCB) and methylsi-lane (MeSiH3 ) whose decomposition supplies the isomeric film-forming precursors H2Si = CH2 and HSiCH3, respectively. Thermal decomposition has been monitored by mass spectrometry and the SiC thin films characterized by scattering spec-trometry (RBS & ERD), FTIR spectroscopy and X-ray diffraction. Deposition rates from the two are comparable, with activation energies of 41 kcal/mole and 53 kcal/mole for SCB and MeSiH3 decomposition, respectively. Silacyclobutane deposits C-rich material lower temperatures, while SiC deposited from MeSiH3 is Si-rich at all temperatures. A mechanism for SiC CVD is proposed that is consistent with the observed kinetics and products.