Effect of buffer layer on the growth of GaN films on sapphire

Abstract

The influence of buffer layer on the growth of GaN epilayer was investigated. Five matching orientations were identified when GaN was directly grown on the sapphire (0001) plane. The use of low-temperature buffer layer significantly improved the epitaxial film quality and the surface morphology. The optimal thickness of buffer layer was about 18 nm - 20 nm in the present growth condition.