Homoepitaxial growth of a-plane GaN layers by reaction between Ga sub(2) O vapor and NH sub(3) gas

Growth of high-quality a-plane GaN layers was performed by reaction between Ga sub(2) O vapor and NH3 gas at a high temperature. Smooth a-plane GaN epitaxial layers were obtained on a-plane GaN seed substrates sliced from thick c-plane GaN crystals. Growth rate increased with increasing Ga sub(2) O partial pressure. An a-plane GaN layer with a growth rate of 48 ?m/h was obtained. The X-ray rocking curve (XRC) measurement showed that the full widths at half maximum (FWHMs) of GaN(1120) with the incident beam parallel and perpendicular to the [0001] direction were 29?43 and 29?42 arcsec, respectively. Secondary ion mass spectrometry (SIMS) measurement revealed that oxygen concentration decreased at a high temperature. These results suggest that growth of a-GaN layers using Ga sub(2) O vapor and NH sub(3) gas at a high temperature enables the generation of high-quality crystals.