6H-SiC单晶(0001)Si-面的表面生长形貌

Surface Growth Morphology of (0001) Si-face of 6H-SiC Single Crystal

利用光学显微镜的反射模式观察了升华法生长的 6H SiC单晶 (0 0 0 1)Si 面的生长形貌 ,应用台阶仪测定了生长台阶高度。实验发现 ,6H SiC单晶的生长台阶呈螺旋状 ,生长台阶呈现出了韵律束合现象。在单晶中间部分 ,生长台阶稀疏 ,台面较宽 ,约 80 μm左右 ,台阶高度较小 ,约 2 0～ 5 0nm ,比较宽的台面上存在小生长螺旋。外围单晶区域 ,生长台阶比较密集 ,其台阶高度较大 ,约 30 0～ 70 0nm ,台面宽度较小 ,约 2～ 5 μm。生长台阶在前进过程中受单晶中的微管缺陷影响 。

Surface growth morphology of (0001) Si-face of 6H-SiC single crystal grown by sublimation was observed by optical microscopy in the reflection mode. The growth step height was determined by using surface profiler. Rhythmic bunching phenomena of the growth step was observed, its terrace width between the growth steps is approximately 80μm and the growth step height ranges from 20 to 50nm. A micro-spiral that lies on the large terrace was also observed. In the periphery region of 6H-SiC single crystal, the dense growth steps have big step heights of 300 to 700nm and small terrace width of 2 to 5μm, approximately. The growth step in the development process is affected by micropipe defect in the single crystal, and the growth step around micropipe is tortuous.