Reciprocal space mapping studies of the initial stage of the PVT growth of 4H-SiC crystals parallel and perpendicular to the c-axis

Defect formation during the initial stage of physical vapor transport (PVT) growth in the [000 (1) over bar] and [11 (2) over bar0] directions has been investigated by x-ray reciprocal space mapping (RSM) and defect-selective etching. RSM studies showed that, while the crystal gown in the [000 (1) over bar] direction did not show a significant degradation of the crystalline quality during the initial stage of growth, the growth in the [11 (2) over bar0] direction resulted in misoriented subgrain structure near the gown crystal/seed interface. The cause of the domain formation is assumed to be the difference in nitrogen concentration between the seed and the grown crystal, and the results indicate that the growth in the [11 (2) over bar0] direction is greatly affected by the nitrogen doping difference.