The facet structures of samples which were grown via epitaxial lateral overgrowth, using low-pressure metal-organic vapour-phase epitaxy, were controlled by varying growth conditions such as the pressure and temperature. The propagation of threading dislocations was investigated for various facet structures. The distribution and density of the threading dislocations were deduced by using the growth pit density method. Two models were proposed: in one model, the dislocations concentrated only in the window area and, in the other model, the dislocations concentrated only in the coalescence region in the center of the mask. In the latter model, the dislocation density fell sharply to the order of 106/cm2; with good reproducibility. The present material exhibited no tilt of the c-axis on the mask area.

Fabrication and Characterization of Low Defect Density GaN Using Facet-Controlled Epitaxial Lateral Overgrowth. K.Hiramatsu, K.Nishiyama, M.Onishi, H.Mizutani, M.Narukawa, A.Motogaito, H.Miyake, Y.Iyechika, T.Maeda: Journal of Crystal Growth, 2000, 221, 316-26