| 摘要 |
PROBLEM TO BE SOLVED: To provide a sapphire substrate for a nitride semiconductor light emitting element, which can constitute a nitride semiconductor light emitting element having excellent light extraction efficiency.SOLUTION: A sapphire substrate includes a plurality of projections on one principal surface, a nitride semiconductor being grown on the one principal surface to form a semiconductor light emitting element. Each of the projections has a bottom surface of a substantially polygonal shape. Each side of the bottom surface includes a depression in the central portion, and whereby each of the projections has extended portions extending from the center thereof toward a tip thereof. The extending direction of each extended portion is within a range of ±10 degrees of the direction in which the a-axis of a sapphire crystal is rotated by 30 degrees. Each of the projection has a plurality of sub-projections formed by dividing the extended portions at the central portion including the center.SELECTED DRAWING: Figure 9 |
