中国物理B ›› 2010, Vol. 19 ›› Issue (7): 76106-076106.doi: 10.1088/1674-1056/19/7/076106
苗瑞霞, 张玉明, 张义门, 汤晓燕, 盖庆丰
Miao Rui-Xia (苗瑞霞), Zhang Yu-Ming (张玉明), Zhang Yi-Men (张义门), Tang Xiao-Yan (汤晓燕), Gai Qing-Feng (盖庆丰)
摘要: This paper reports that the etching morphology of dislocations in 8o off-axis 4H-SiC epilayer is observed by using a scanning electronic microscope. It is found that different types of dislocations correspond with different densities and basal plane dislcation (BPD) array and threading edge dislocation (TED) pileup group lie along some certain crystal directions in the epilayer. It is concluded that the elastic energy of threading screw dislocations (TSDs) is highest and TEDs is lowest among these dislocations, so the density of TSDs is lower than TEDs. The BPDs can convert to TEDs but TSDs can only propagate into the epilyer in spite of the higher elastic energy than TEDs. The reason of the form of BPDs array in epilayer is that the big step along the basal plane caused by face defects blocked the upstream atoms, and TEDs pileup group is that the dislocations slide is blocked by dislocation groups in epilayer.
中图分类号: (Defects and impurities: doping, implantation, distribution, concentration, etc.)