Patent ID: 7199401

Claim:
A light-emitting semiconductor device of improved efficiency, comprising: (a) a semiconductor region comprising a first and a second semiconductor layer of opposite conductivity types for generating light, the semiconductor region having a first major surface at which the first semiconductor layer is exposed and from which is emitted the light, and a second major surface, opposite to the first major surface, at which the second semiconductor layer is exposed; (b) an electrode electrically connected to the first semiconductor layer of the semiconductor region; (c) an ohmic contact layer in ohmic contact with at least part of the second major surface of the semiconductor region, the ohmic contact layer being pervious to the light generated by the semiconductor region; (d) a reflective layer of electrically conducting material held against the ohmic contact layer for reflecting the light that has traversed the ohmic contact layer, back toward the semiconductor region for emission from the first major surface thereof; and (e) a transparent antidiffusion layer interposed between the ohmic contact layer and the reflective layer in order to prevent the ohmic contact layer and the reflective layer from thermally diffusing from one into the other.