Gallium nitride semiconductor substrate

摘要

A method of fabricating a single crystal gallium nitride substrate the step of cutting an ingot of single crystal gallium nitride along predetermined planes to make one or more single crystal gallium nitride substrates. The ingot of single crystal gallium nitride is grown by vapor phase epitaxy in a direction of a predetermined axis. Each predetermined plane is inclined to the predetermined axis. Each substrate has a mirror polished primary surface. The primary surface has a first area and a second area. The first area is between an edge of the substrate and a line 3 millimeter away from the edge. The first area surrounds the second area. An axis perpendicular to the primary surface forms an off-angle with c-axis of the substrate. The off-angle takes a minimum value at a first position in the first area of the primary surface.

主权项

1. A gallium nitride substrate with a primary surface for epitaxial growth of a III nitride semiconductor, the gallium nitride substrate, wherein:
the primary surface has an off-angle, the off-angle being formed by c-axis of the gallium nitride substrate with an axis perpendicular to the primary surface, and the off-angle being not less than 0.15 degrees, and a c-face of the gallium nitride substrate is concave or convex, a curvature radius of R of a C-plane of the gallium nitride substrate being equal to or more than 1.5 meters.