| Abstract: | Three main technologies for bulk GaN growth,i.e.,hydride vapor phase epitaxy(HVPE),Na-flux method,and ammonothermal method,are discussed.We report our recent work in HVPE growth of GaN substrate,including dislocation reduction,strain control,separation,and doping of GaN film.The growth mechanisms of GaN by Na-flux and ammonothermal methods are compared with those of HVPE.The mechanical behaviors of dislocation in bulk GaN are investigated through nano-indentation and high-space resolution surface photo-voltage spectroscopy.In the last part,the progress in growing some devices on GaN substrate by homo-epitaxy is introduced. |
