Determination of the diffusion lengths of Ga adatoms using GaN stripe profiling

Abstract

We present a method for determining the diffusion lengths of Ga adatoms on GaN by combining profiling of the tops of GaN stripes obtained by selective area MOCVD and a diffusion growth model. We deduce very high values of the diffusion lengths on tops of <11–20>‐oriented stripes at 1040 °C which range from 6 μm under nitrogen‐rich to 24 μm under hydrogen‐rich atmosphere in the reactor. The obtained results show in particular that Ga‐catalyzed growth of GaN nanostructures and nanowires should not be limited by Ga influx and thus the exceptional growth rate is anticipated in such cases.