Patent ID: 7932114
Filing Date: 2011-04-26
Classification: C30B

Abstract:
1. A method of manufacturing a GaN substrate having a c-plane for manufacturing an epitaxialwafer by successively stacking at least two layers including an Al x Ga (1-x) N layer having an Al composition x greater than zero and not more than 0.3 and a thickness greater than zero and not more than 30 nm and a GaN layer on said c-plane, comprising the steps of: deciding a value t where t 1 (m) represents the thickness of said GaN substrate, r(m) represents the radius of said GaN substrate, t 2 (m) represents the thickness of said Al x Ga (1-x) N layer, x represents the Al composition in said Al x Ga (1-x) N layer, h(m) represents a warp of said epitaxialwafer, a 1 represents the lattice constant of GaN and a 2 represents the lattice constant of AlN; and cutting out said GaN substrate having a thickness of at least said minimum thickness and less than 400 μm from an ingot of GaN.