Critical impact of Ehrlich–Schwöbel barrier on GaN surface morphology during homoepitaxial growth

We discuss the impact of kinetics, and in particular the effect of the Ehrlich–Schwöbel barrier (ESB), on the growth and surface morphology of homoepitaxial GaN layers. The presence of an ESB can lead to various self-assembled surface features, which strongly affect the surface roughness. We present an in-depth study of this phenomenon on GaN homoepitaxial layers grown by metal organic vapor phase epitaxy and molecular beam epitaxy. We show how a proper tuning of the growth parameters allows for the control of the surface morphology, independent of the growth technique.