【摘要】 本文在背景Ar气压力为8×104Pa、温度为1800~2000℃的条件下,对升华法生长S iC单晶的籽晶进行了原位退火处理,利用原子力显微镜和光学显微镜对退火后的6H-S iC晶片表面进行了观察,研究了退火温度和时间对晶片表面的影响。发现经过退火处理后的籽晶表面存在规则的生长台阶,有助于侧面生长模式的发展,进一步有助于台阶流生长模式的发展。通过对籽晶的退火处理,降低了螺旋生长中心的密度,从而减少多型夹杂、小角度晶界和微管等缺陷的出现,提高了晶体质量。更多还原

【Abstract】 The seeds of 6H-SiC crystal grown by sublimation method were in-situ annealed at 8×10~4Pa Ar atmosphere and the temperature ranges between 1800℃ and 2000℃.The morphologies of 6H-SiC seed surfaces after annealing treatment were observed by optical microscopy and atomic force microscopy.The influence of annealing temperature and time on seed surface was studied.It has been found that there exist some regular spiral steps on the seed surfaces after annealing and these steps may promote a better lateral growth mechanism and further more the preferable step flow growth mechanism.With annealing treatment,the density of spiral growth center on the seed surface was reduced.It implies that other growth defects such as polytype inclusions,low-angle grain boundaries and micropipes will be reduced following the crystal growth and 6H-SiC crystalline quality will be improved.更多还原