Homoepitaxial growth of a-plane GaN layers by reaction between Ga2O vapor and NH3 gas

Abstract

Growth of high-quality a-plane GaN layers was performed by reaction between Ga2O 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 Ga2O partial pressure. An a-plane GaN layer with a growth rate of 48 µm/h was obtained. The X-ray rocking curve (XRC) measurement showed that the full widths at half maximum (FWHMs) of GaN 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 Ga2O vapor and NH3 gas at a high temperature enables the generation of high-quality crystals.