GaN Substrates—Progress, Status, and Prospects

Recent advances in the research, development, and commercial production of native GaN substrates with low defect density and high structural and optical quality have attracted a renewed interest in development of nitride devices based on native substrates. The still low yet rapidly increasing availability of native GaN substrates opens the full potential of GaN devices and has accelerated progress in the development of several electronic and optoelectronic devices. In this paper, progress in the primary competing growth techniques for producing native GaN substrates will be reviewed. The technological issues pertaining to faster scalability of GaN substrate production will be discussed. The current state-of-the-art substrate material properties and the future prospects for the growth approaches and substrate quality will be presented.