Dramatic increase the growth rate of GaN layers grown from Ga2O vapor by epitaxial growth on HVPE-GaN substrates with a well-prepared surface

A GaN growth technique using Ga2O vapor allows high-temperature growth, which results in high-crystalline GaN. In this study, we succeeded in increasing the growth rate up to 180 mu m/h, and with this technique, we maintained the crystallinity of the epitaxial layers at the same level as the crystallinity of the seed substrates [the FWHM of the (0002) GaN X-ray rocking curve was 71 '']. To achieve this improvement, growth occurred on atomically smooth, damage-free seed substrates prepared by chemical mechanical polishing (CMP), and these substrates were subjected to a subsequent H-2 heating process. Moreover, for this growth process, both a high temperature (1200 degrees C) and a H-2/N-2 atmosphere were also found to improve crystallinity. (C) 2014 The Japan Society of Applied Physics