Properties of GaN homoepitaxial layers grown on GaN epitaxial wafers

The lack of GaN substrates is a limiting factor for the development of III-V nitride devices. Recently we proposed to use GaN/SiC epitaxial wafers, consisting of thin GaN layer deposited by hydride vapor phase epitaxy (HVPE) on SIC wafer, as substrates for subsequent growth of III-V nitrides and devices development. These wafers are attractive to be used as substrates for GaN device fabrication because the GaN-based device structures can be grown on these wafers by homoepitaxy without any buffer layer. Due to high SiC thermoconductivity and cleavage possibility, these wafers are especially attractive for high-power electronic and optoelectronic applications. In this paper, we focus on crystal structure, optical and electrical properties of GaN homoepitaxial layers and p-n structures grown by HVPE on GaN/SiC epitaxial wafers. New types of m-V nitride epitaxial wafers are described, insulating GaN/SiC epitaxial wafers and AlN/SiC epitaxial wafers.