Dramatic increase in the growth rate of GaN layers grown from Ga_2O vapor by epitaxial growth on HVPE-GaN substrates with a well-prepared surface

摘要

A GaN growth technique using Ga_2O vapor allows high-temperature growth, which results in high-crystalline GaN. In this study, we succeeded in increasing the growth rate up to 180 μm/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 ℃) and a H_2/N_2 atmosphere were also found to improve crystallinity.