Growth, Separation and Properties of HVPE Grown GaN Films using Different Nucleation Schemes

Abstract

In this paper, we review the present knowledge of the key growth-related properties of thick HVPE-GaN films relevant for the quasi-substrate application. We begin by describing the morphology and structure typical for thick films grown at very high growth rates, and concentrate on large-scale interface defects and their impact on the crystal quality. Different nucleation schemes were used like reactively sputtered AlN and MOVPE grown GaN high temperature buffers, as well as more complicated Pendeo and two step lateral overgrown template structures. The effect of the different buffers on the overall crystal quality and on the critical thick- ness for crack appearance, as well as on the sapphire separation process was studied