Growth of semipolar {20-21} GaN and {20-2-1} GaN for GaN substrate

摘要

In this article, we present a semipolar {20-21} GaN layer and {20-2-1} GaN layer for large GaN substrates. The {20-21} GaN layer was fabricated on {22-43} patterned sapphire substrates ( PSSs) by metal-organic vapor-phase epitaxy ( MOVPE) and hydride vapor-phase epitaxy ( HVPE). We found that the surface roughening and crack generation during the HVPE growth were suppressed by the formation of SiO2-striped masks parallel to the c-axis on the MOVPE-grown {20-21} GaN template. Furthermore, we demonstrated millimeter-thick crystal growth on a {20-21} GaN layer and a {20-2-1} GaN layer on a GaN substrate using HVPE. The dark-spot density in the {20-2-1} GaN layer was approximately 9.6 x 10(6) cm(-2) for 960 min growth. The darkspot density in the {20-2-1} GaN layer decreased more rapidly than that in the {20-21} GaN layer as growth thickness increased. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim