Effects of additive carbon source on growth of SiC single crystal

Effects of additive carbon source on crystal growth process conducted by physical vapor transport method (PVT), have been studied. Active carbon was appended to the source material. The change of graphitization degree of crucible and active carbon were subjected to XRD before and after the process of crystal growth. The defects of crystal were investigated by optical microscopy. The experimental results indicate that with the progress of crystal growth the activity of graphite crucible would decrease, resulting in degrading of the growth rate of crystal and augment the probability of defects formation. Appending active carbon could provide plenty carbon source for crystal growth and enhance the growth rate of crystal; furthermore, it would restrain the formation of Si liquid phase, which reduces the occurrence of defects.