Patent ID: 8299486

Claim:
A semiconductor light emitting device comprising: a C plane (0001) sapphire substrate comprising a plurality of protrusions that are disposed on a surface of the sapphire substrate in a two-dimensionally repeated pattern; a plurality of GaN-based semiconductor layers epitaxially grown on the sapphire substrate; and an ohmic electrode formed on the GaN-based semiconductor layers, wherein the semiconductor light emitting device is configured so that light generated in the GaN-based semiconductor layers is emitted from the ohmic electrode or the sapphire substrate, the protrusions are configured to scatter or diffract light generated in the semiconductor layers, the repeated pattern of the protrusions is such that six protrusions forming a hexagon surround another protrusion, in plan view of the sapphire substrate the hexagon has sides that are parallel to A-axis of the sapphire substrate, and in plan view of the sapphire substrate the protrusions have a shape of a triangle having sides that are not parallel to A-axis of the GaN-based semiconductor layers.