Patent ID: 7683386

Claim:
A semiconductor light emitting device comprising: a transparent substrate including a surface for growing semiconductor layers including an active layer, said surface having protrusions, with a side face of each of said protrusions defining a first inclination angle on a lower portion of said side face and a second inclination angle on an upper portion of said side face, said first inclination angle being greater than said second inclination angle; and semiconductor layers, of material different from a material of said transparent substrate, on said surface of said transparent substrate, said semiconductor layers covering said protrusions, wherein either (i) said upper portion of said side face of each of said protrusions is flat and said lower portion of said side face of each of said protrusions is rough, or (ii) said upper portion of said side face of each of said protrusions has a surface roughness that is smaller than a surface roughness of said lower portion of said side face of each of said protrusions, wherein light is reflected at an interface between said protrusions and said semiconductor layers, and wherein a groove is formed at a bottom periphery of each of said protrusions.