Patent ID: 6979844

Claim:
A light-emitting semiconductor device having a gallium nitride-based compound semiconductor, comprising: (A) a baseplate made from a silicon containing impurities and having a low resistivity; (B) a buffer layer formed on all of one major surface of said baseplate, said buffer layer comprising an alternating lamination of a plurality of first sublayers and second sublayers: (a) each said first sublayer composed of Al x Ga 1−x N, where 0<x≦1, each-first sublayer having a thickness ranging from about 5×10 −4 micrometers to about 100×10 −4 micrometers and having a quantum-mechanical tunnel effect; (b) each said second sublayer composed of GaN or Al y Ga 1−y N, where y<x and 0<y<1, each second sublayer containing n-type impurities comprising silicon and having an electrical conductivity and a thickness ranging from about 5×10 −4 micrometers to about 2000×10 −4 micrometers; (C) a semiconductor region disposed on said buffer layer and containing a plurality of gallium nitride-based compound semiconductors for emission of light; (D) a first electrode connected to said semiconductor region; and (E) a second electrode connected to another major surface of said baseplate.