METHOD FOR GROWTH OF GAN SINGLE CRYSTAL, METHOD FOR PREPARATION OF GAN SUBSTRATE, PROCESS FOR PRODUCING GAN-BASED ELEMENT, AND GAN-BASED ELEMENT

摘要

A GaN-based thin film (thick film) is grown using a metal buffer layer grown on a substrate. (a) A metal buffer layer (210) formed of Cr, Cu or the like was vapor deposited on a sapphire substrate (120). (b) A substrate comprising a metal buffer layer (210) formed by vapor deposition on a sapphire substrate (120) is nitrided in an ammonia gas atmosphere to form a metal nitride layer (212). (c) A GaN buffer layer (222) is grown on the nitrided metal buffer layers (210, 212). (d) Finally, a GaN single crystal layer (220) is grown. This GaN single crystal layer (220) can be grown to various thicknesses depending upon the purposes. A free standing substrate can be prepared by selective chemical etching of the substrate produced by the above process. Further, the substrate produced by the above process can also be used as a GaN template substrate for the preparation of GaN-based light emitting diodes and laser diodes.