Improvement of crystallinity of GaN layers grown using Ga2O vapor synthesized from liquid Ga and H2O vapor

• Published in: Japanese Journal of Applied Physics Vol. 55; no. 5S
• Main Authors: Yamaguchi, Yohei, Taniyama, Yuuki, Takatsu, Hiroaki, Kitamoto, Akira, Imade, Mamoru, Yoshimura, Masashi, Isemura, Masashi, Mori, Yusuke
• Format: Journal Article
• Language: English
• Published: The Japan Society of Applied Physics 01.05.2016
• ISSN: 0021-4922; 1347-4065
• DOI: 10.7567/JJAP.55.05FB04

Growth methods using Ga2O vapor allow long-term growth of bulk GaN crystals. Ga2O vapor is generated by the reduction of Ga2O3 powder with H2 gas (Ga2O3-H2 process) or by the oxidation of liquid Ga with H2O vapor (Ga-H2O process). We investigated the dependence of the properties of grown GaN layers on the synthesis of Ga2O. In the Ga-H2O process, the polycrystal density and full width at half maximum (FWHM) GaN(0002) X-ray rocking curves (XRC) at a high growth rate were lower than those in the Ga2O3-H2 process, and a GaN layer with FWHM of 99 arcsec and growth rate of 216 µm/h was obtained. A low H2O partial pressure in the growth zone improved crystallinity in the Ga-H2O process, realized by the high efficiency of conversion from liquid Ga to Ga2O vapor. We concluded that using Ga2O vapor in the Ga-H2O process has the potential for obtaining higher crystallinity with high growth rate.