Study of stress in ammonothermal non polar and semi polar GaN crystal grown on H

GaN crystals were grown on non-polar and semi-polar HVPE GaN seeds by basic ammonothermal method. Stress distributions were investigated in cross-section of (1 1 −2 0) plane, (1 0 −1 0) plane, (2 0 −2 1) plane and (1 0 −1 1) plane GaN crystal. The cathodoluminescence (CL) images show cross-section information clearly and each examined object consisted of hydride vapor phase epitaxy (HVPE) seed and ammonothermal GaN (Am-GaN). The impurity concentration and free carrier concentration were estimate