Evaluation of the surface stoichiometry during molecular beam epitaxy of cubic GaN on (001) GaAs

Abstract

We use in situ reflection high‐energy electron diffraction to investigate the growth kinetics of cubic (001)‐GaN/GaAs grown by plasma‐assisted molecular beam epitaxy. We find that the GaN surface exhibits three surface reconstructions having (1×1), (2×2), and c(2×2) symmetries, which correspond to Ga adatom coverages of 0, 0.5, and 1, respectively. We demonstrate that the transient behavior of the half‐order streak intensity is a sensitive probe of the surface stoichiometry during growth. Particularly, these measurements enable us to directly determine the effective N flux incorporated into the crystal.