Non-polar and semi-polar ammonothermal GaN substrates

Abstract

In this paper we review the developments of producing non-polar (i.e. m-plane and a-plane) and semi-polar (i.e. (20.1)-plane) wafers by ammonothermal method. The growth method and polishing results are described. We succeeded in producing 26 mm×26 mm non- and semi-polar wafers. These wafers possess outstanding structural and optical properties, with threading dislocation density of the order of 10 4cm 3. Detailed studies of homoepitaxial layers, as well as AlGaN heterostructures are also presented, showing the potential of studied ammonothermal substrates in the fabrication of optoelectronic devices. © 2012 IOP Publishing Ltd.