A procedure for the optimization of a 3C-SiC buffer layer for the deposition of 3C-SiC/(001) Si is described. After a standard carbonization at 1125 degrees C, SiH4 and C3H8 were added to the gas phase while the temperature was raised from 1125 degrees C to the growth temperature of 1380 degrees C with a controlled temperature ramp to grow a thin SiC layer. The quality and the crystallinity of the butler layer and the presence avoids at the SiC/Si interface are related to the gas flow and to the heating ramp rate. In order to improve the buffer quality the SiH4 and C3H8 Bows were changed during the heating ramp. On the optimized butler no voids were detected and a high-quality 1.5 mu m 3C-SiC was grown to demonstrate the effectiveness of the described buffer. (C) 2013 Elsevier B.V. All rights reserved.