Patent ID: 7504324

Claim:
A method for manufacturing a semiconductor base comprising a substrate and a GaN group semiconductor crystal defined by Al x Ga 1-x-y In y N wherein 0≦x≦1 and 0≦y≦1, which is formed on the substrate by vapor phase growth, which method comprises: (a) preparing the substrate for crystal growth, wherein the substrate is made of sapphire (C-plane, A-plane, R-plane), SiC (6H, 4H, 3C), Si, Spinel, ZnO, GaAs, or NGO, and a crystal growth plane of the substrate is a plane having concave parts with a bottom surface formed by etching the original substrate, which consequently contains concaves and convexes formed by the concave parts and the remaining convex parts, and wherein the convex parts are of an interspersing island type, and (b) growing the GaN group semiconductor crystal from an upper part of the convex parts and from the bottom surface of the concave parts, respectively, such that the crystals grown laterally from the upper part of the convex parts and the crystals grown from the bottom surface of the concave parts are joined to cover the crystal growth plane of the substrate.