Patent ID: 8283239

Claim:
A method of manufacturing low defect density GaN involving the following steps: a) growth of an epitaxial layer of GaN directly on a surface of a substrate, wherein the substrate is chosen from the group consisting of sapphire, spinel, GaN, AlN, GaAs, Si, SiC (6H-, 4H-, 3C-), LiAlO 2 , LiGaO 2 , ZrB 2 , and HfB 2 ; b) subsequent growth of a GaN layer to form island features; and c) growth of a GaN layer from the island features at conditions where lateral growth is enhanced until full coalescence of the island features without using any kind of mask, wherein step b) is achieved without using any kind of mask, nor roughening, nor etching, nor grooving the GaN surface, and only by changing a combination of the operating pressure in the growth chamber, the partial pressure, the temperature, the V/III ratio and/or surfactant or antisurfactant chemical species in the vapour phase, wherein the temperature during step b) is below 950° C., and wherein growth of the GaN layer is carried out at a rate of at least about 50 microns/hour.