Patent ID: 7772605

Claim:
A compound semiconductor light-emitting device comprising: a substrate having an upper surface, a lower surface, and a plurality of device side surfaces; and a light-emitting layer grown on the upper surface of said substrate, wherein at least one of the device side surfaces has an array of recessed portions, individual ones of the recessed portions extend from the lower surface to the upper surface of the substrate, and individual ones of the recessed portions have a semi-circular shape in cross section parallel to the upper surface of the substrate, and wherein the depth of individual ones of the recessed portions is a radius of the semi-circular shape in a direction parallel to the upper surface of the substrate, and the height of individual ones of the recessed portions from the lower surface to the upper surface of the substrate is at least 20 μm, and wherein a distance of 4 to 40 μm is maintained between adjacent recessed portions in the array of the recessed portions.