Growth optimization toward low angle incidence microchannel epitaxy of GaN using ammonia-based metal-organic molecular beam epitaxy

► {112̄0} and {112̄2} sidewalls formed when [NH3]/[TMG] R<50 and R>100, respectively. ► Low ratio of R <50 is considered suitable for MCE of GaN. ► Growth temperature and the R ratio are optimized at 820 °C and 40, respectively. ► 6 μm wide lateral overgrowth of GaN was successfully achieved by LAIMCE. ► No pits appear on lateral growth region of GaN surface after etching by H3PO4.