Monocrystalline GaN Diluted with up to 7% Arsenic Grown by MOVPE

Abstract

The growth of GaNAs with arsenic is important due to band engineering in the valence band of GaN, but it is very challenging due to the difference in the optimal growth temperatures for GaN and GaAs. In this study, we present the results of growing GaNAs via metal−organic vapor phase epitaxy with trimethylarsine as the arsenic source. By reducing the growth temperature and increasing the V/III ratio, we obtained an As content of up to 7.6%. Crystalline material quality and composition were investigated with high-resolution X-ray diffraction. Atomic force microscopy determined surface roughness root-mean-square values between 0.4 and 2 nm. The internal structure of the layers was investigated via transmission electron microscopy, proving their high crystalline quality. It also showed that further reduction of growth temperature resulted in the formation of a zincblende GaAs polycrystalline layer.