Patent ID: 7342261

Claim:
A light emitting device, comprising: a substrate having a patterned surface and formed with a plurality of spaced apart cavities that are indented inwardly from said patterned surface, each of said cavities being defined by a cavity-defining wall; and an epitaxial layer formed on said patterned surface of said substrate, having a patterned surface that is in face-to-face contact with said patterned surface of said substrate, and formed with a plurality of protrusions that protrude from said patterned surface of said epitaxial layer and that are respectively received in said cavities, each of said protrusions being polygonal in shape and defining a plurality of vertices; wherein said vertices of each of said protrusions contact said cavity-defining wall of the respective one of said cavities so as to form a plurality of closed pores between each of said protrusions and said cavity-defining wall of the respective one of said cavities.