화학공학소재연구정보센터
Journal of Crystal Growth, Vol.408, 1-6, 2014
Defect formation during the initial stage of physical vapor transport growth of 4H-SiC in the [11(2)over-bar0] direction
Defect formation during the initial stage of physical vapor transport (PVT) growth of 4H-SiC in the [11 (2) over bar0] direction has been investigated by x-ray reciprocal space mapping (RSM), defect-selective etching, and low-voltage scanning electron microscopy. RSM studies showed that 4H-SiC crystals grown in the [11 (2) over bar0] direction showed a significant degradation of crystalline quality during the initial stage of PVT growth, compared with crystals grown in the [000 (1) over bar] direction; the growth in the [11 (2) over bar0] direction resulted in a misoriented domain structure near the grown crystal/seed interface. At the interface, high densities of basal plane dislocations, extending parallel to the interface, and threading edge dislocations along the c-axis were observed. The former caused a tilt domain boundary around an axis parallel to [1 (1) over bar 00]. Based on the results, the paper discusses the defect formation mechanism during the initial stage of PVT growth in the [11 (2) over bar0] direction and points to the difference in nitrogen concentration between the seed and the grown crystal as a cause of the observed domain and dislocation structure at the grown crystal/seed interface. (C) 2014 Elsevier B.V. All rights reserved.