Pseudomorphic growth of a thin-GaN layer on the AlN single-crystal substrate using metal organic vapor phase epitaxy

In this study, a 21 nm thick GaN layer with a single-step terrace surface was pseudomorphically grown on an AlN single-crystal substrate using metal organic vapor phase epitaxy by increasing the growth rate up to 1 mu m h-1 at a growth temperature of 850 degrees C and a reactor pressure of 5 kPa. The growth temperature and rate were found to be the factors dominating the flatness and coverage of the thin-GaN layer, revealing that controlling the degree of Ga migration is crucial. Furthermore, threading dislocations was not observed for the thin-GaN layer, with a flat surface, grown on the AlN substrate.