附加碳源对SiC单晶生长过程的影响

研究了用物理气相传输（PVT）法制备SiC单晶的过程中附加碳源对晶体生长速度及缺陷的影响，并将活性炭与SiC粉末一起加入到石墨坩埚中进行晶体生长。用XRD分别测定了晶体生长前后坩埚与活性炭的石墨化度，并用光学显微镜观察了晶体中的缺陷。结果表明，随晶体生长过程的进行石墨坩埚的活性降低，直接导致晶体生长速度减慢，并使籽晶表面Si液相形成的可能性增大，与Si液相相关的缺陷增多。活性炭的加入给生长过程提供了充足的碳源，提高了晶体的生长速度，并抑制了籽晶表面Si液相的形成，从而降低了与Si液相相关缺陷出现的几率。

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.