This paper reports that the etching morphology of dislocations in 8° off-axis 4H-SiC epilayer is observed by using a scanning electronic microscope. It is found that different types of dislocations correspond wit...This paper reports that the etching morphology of dislocations in 8° 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.展开更多
基金supported by the National Natural Science Foundation of China (Grant No. 0876061)Shaanxi 13115 Innovation Engineering of China (Grant No. 2008ZDKG-30)the defence Fund of China (Grant No. 9140A08050508)
文摘This paper reports that the etching morphology of dislocations in 8° 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.
