Patent ID: 7687382

Claim:
A method of making a group III nitride-based compound semiconductor, comprising: providing a semiconductor substrate comprising group III nitride-based compound semiconductor; polishing a surface of said semiconductor substrate such that said polished surface includes an inclined surface that has an off-angle θ of 0.15 degrees or more and 0.6 degrees or less to one of an a-face, a c-face and an m-face of the semiconductor substrate; and growing a semiconductor epitaxial growth layer of group III nitride-based compound semiconductor on the polished surface of the semiconductor substrate, said growing said semiconductor epitaxial growth layer comprising inducing step-flow growth by said off-angle θ, wherein said polished surface comprises said a-face and growing said semiconductor epitaxial growth layer comprises growing a layer of group III nitride-based compound semiconductor on said a-face, and said off-angle θ is given by θ=√(θ 1 2 +θ 2 2 ), where θ 1 is an off-angle to an c-axis direction, and θ 2 is an off-angle to an m-axis direction.