Growth of high-quality cubic GaN on (001) GaAs by halide VPE with backside buffer

Abstract

It is reported that arsenic (As) act as a surfactant in growth of cubic GaN by GSMBE, and that it improves quality of cubic of the grown layer. In this paper, we report that it is true for Halide Vapor Phase Epitaxy (HVPE) of GaN, however, it deteriorates photoluminescence intensity of the grown layer very much. It was found that in order to get optically high quality cubic GaN, it is important to prevent incorporation of As. The As autodoping in HVPE was suppressed by growing GaN layer on back side of the substrate, too. The photoluminescence intensity was improved by more than one order to magnitude by preventing the As autodoping. In HVPE, we can grow thick and pure GaN layers, though it is said that when the grown thickness exceeds 1.5 micrometers , more than 10 percent hexagonal phase is introduced for gas source molecular beam epitaxy and metalorganic vapor phase epitaxy growth of cubic GaN. Best value of the cubic component for HVPE was 2 micrometers with the cubic component of more than 99 percent.