Patent ID: 8513645
Filing Date: 2013-08-20
Classification: B82Y,C30B,H01L,H01S

Abstract:
1. A gallium nitride-based epitaxial wafer comprising: a gallium nitride substrate including a main surface; one or more gallium nitride-based semiconductor films grown on the main surface of the gallium nitride substrate; and an active layer including a quantum well structure, the active layer being grown on the gallium nitride-based semiconductor film; wherein the active layer includes a well layer composed of a gallium nitride-based semiconductor containing indium as a Group III element, an off-angle between a line normal to the main surface and a C-axis of the gallium nitride substrate has a distribution over the main surface and also monotonically varies on a line segment extending from one point on an edge of the main surface to another point on the edge, and the off-angle at a first point on the main surface is smaller than the off-angle at a second point on the main surface, and a thickness of the well layer on the first point is smaller than a thickness of the well layer on the second point, wherein a reference plane is defined by the line segment and the <1-100> crystal axis or the <11-20> crystal axis, and the line segment is oriented such that the reference plane is orthogonal to the main surface.