| abstract |
To provide a GaN-laminated substrate comprising an underlying sapphire substrate on which the planes of various plane orientations are laminated, such as a substrate having, as a main plane, an a-plane: <11-20>-plane, an m-plane: <1-100>-plane or a <11-22>-plane of GaN having low through dislocation density and high crystallinity, and a method of producing the same. A gallium nitride crystal-laminated substrate includes an underlying sapphire substrate and a gallium nitride crystal layer formed by growing crystals thereof on the underlying substrate, the gallium nitride crystal layer growing by epitaxial lateral overgrowth on the side walls of, for example, a c-plane in the grooves formed in a plural number in the main plane of the underlying sapphire substrate to thereby form the surface thereof in parallel with the main plane, the surface thereof comprising a non-polar plane such as a-plane or m-plane, or a semipolar plane such as <11-22>-plane, and a dark point density of the gallium nitride crystals being less than 2*10<SP>8</SP>/cm<SP>2</SP>, preferably, not more than 1.85*10<SP>8</SP>/cm<SP>2</SP> and, particularly preferably, not more than 1.4*10<SP>8</SP>/cm<SP>2</SP>. |