Method of making group iii nitride-based compound semiconductor

Abstract

A method of making a group III nitride-based compound semiconductor includes 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, providing a stripe-shaped specific region on the polished surface, the specific region comprising a material that prevents the growth of the group III nitride-based compound semiconductor on its surface, and growing a semiconductor epitaxial growth layer of group III nitride-based compound semiconductor on the polished surface of the semiconductor substrate. The specific region is provided on the polished surface such that the longitudinal direction of the specific region intersects with the longitudinal direction of a step portion that is formed with an atom-layer height on the polished surface by introducing the off-angle θ.