Synchrotron radiation X-ray topography and defect selective etching analysis of threading dislocations in halide vapor phase epitaxy GaN crystal grown on ammonothermal seed

Halide vapor phase epitaxy GaN crystal is examined, in terms of threading dislocations, by two experimental techniques: synchrotron radiation X-ray topography and defect selective etching. The obtained results are analyzed and compared. Three kinds of threading dislocations are found. Other defects in the crystal are also shown. A correlation between defects determined by the two experimental methods is presented and discussed. (C) 2019 The Japan Society of Applied Physics