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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。
The effect of additional carbon sources on the growth rate and defects of SiC crystals during the preparation of SiC single crystals by physical vapor deposition (PVT) was studied. Activated carbon and SiC powders were added into graphite crucible for crystal growth. The graphitization degree of the crucible and activated carbon before and after the crystal growth was measured by XRD and the defects in the crystal were observed with an optical microscope. The results show that the decrease of the activity of graphite crucible during the process of crystal growth directly leads to the slowing of crystal growth and the possibility of Si liquid phase formation on the seed surface. The defects associated with Si liquid phase increase. Activated carbon added to the growth process to provide a sufficient carbon source to improve the growth rate of the crystal, and inhibit the formation of liquid crystal Si surface, thus reducing the liquid phase defects associated with the probability of Si.