Carbonized buffer layers were formed on Si (100) nominally oriented substrates with propane diluted in palladium purified hydrogen in a cold wall vertical reactor. Subsequent SiC layers were grown using silane and propane at atmospheric pressure. The growth temperature was ranging from 1150°C to 1350°C. The layers obtained were characterized by LT photoluminescence, IR reflectivity, X-ray diffraction, micro-Raman on cleaved edges, AFM imaging, and optical microscopy. Drastic influence on the layer surface morphology was evidenced depending on the transition step between the carbonization and the SiC epitaxial growth. As a result, we have developed a carbonization process leading to very high quality 3CSiC films grown at 1250°C.