The structure, strain and defect density of SiC thin films epitaxially deposited on 6H-SiC (0001), Si(111) and Si(001) from the single-source organosilane precursor silacyclobutane (c-C3H6SiH2) were determined by X-ray double crystal diffractometry and topographic methods. All the films grown on Si were found to be 3C-SiC type. The films grown on 6H-SiC (0001) at 800 to 1000 degrees C were found to be 3C-SiC type, whereas the films grown on 6H-SiC (0001) at 1100 degrees C were a mixture of 3C, 4H and 6H polytypes of SiC. All the films grown on Si had very high defect densities. However, the defect density was reduced by a factor of 10(4) for the films of similar thickness on 6H-SiC (0001), with the film grown at 900 degrees C being the optimum one exhibiting structural properties nearly equal to those of the substrate.