Growth of Thick GaN Films with High Growth Rate Using Sublimation Method under High Pressure

We found that the growth rate of GaN is much higher using the sublimation method under high pressure than under normal pressure. It seems that the high thermal decomposition temperature under high pressure suppresses the decomposition of the growing GaN film. A growth rate of 130 µm/h was achieved by optimizing the growth temperature and the ambient pressure. This growth rate is as high as that achieved through hydride vapor phase epitaxy (HVPE). The GaN crystals were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD).