Photo-functional device

Claim 1

A photo-functional device comprising: an n-type semiconductor substrate; a light emitting means disposed on one face of said substrate by successively laminating an n-type AlGaAs layer, an n-type GaAs layer, a p-type GaAs layer, an n-type AlGaAs layer and an n-type GaAs layer in such a manner that Zn impurities are diffused into said layers from the uppermost n-type GaAs layer to the lower most n-type GaAs layer and a p-n junction is formed in said semiconductor layers; a light receiving means disposed on said one face of said substrate by successively laminating an n-type AlGaAs layer, an n-type GaAs layer, a p-type GaAs layer, an n-type AlGaAs layer and an n-type GaAs layer so as to form the same laminate as that of said light emitting means and to form a heterojunction phototransistor in the laminate thereof; a groove disposed between said light emitting means and said light receiving means for converting a coupling rate of light coupled from said light emitting means to said light receiving means, said groove reaching at least the lowermost n-type GaAs layer; two electrodes respectively disposed on a top face of said light emitting means and a top face of said light receiving means, the two electrodes being electrically connected in series; an insulation film disposed in said groove; and a metal layer disposed on an upper surface of said insulation film.