Patent ID: 7187048

Claim:
A semiconductor light-receiving device comprising: a semiconductor substrate having a first surface on a light-receiving side and a second surface on the opposite side to said first surface, said semiconductor substrate comprising a first conductivity type; a semiconductor layer formed on said first surface of said semiconductor substrate; a plurality of first semiconductor regions formed in said semiconductor layer so as to reach said semiconductor substrate from a surface of said semiconductor layer, said plurality of first semiconductor regions being formed apart from each other, and comprising the first conductivity type; a second semiconductor region selectively formed in a surface region of said semiconductor layer, said second semiconductor region having a lattice form or a network form to surround each of said plurality of first semiconductor regions with surface portions of said semiconductor layer therebetween and comprising a second conductivity type; a first electrode formed on said second semiconductor region and having a lattice form or a network form; a second electrode formed on said second surface of said semiconductor substrate; said surface portions of said semiconductor layer between each of said plurality of first semiconductor regions and said second semiconductor region having higher resistances than resistances of said plurality of first semiconductor regions and said second semiconductor region; and depletion regions predominantly spreading in directions along the surface of said semiconductor layer between said second semiconductor region and each of said plurality of first semiconductor regions configured to deplete said surface portions of said semiconductor layer completely in a state in which a reverse bias is applied between said first electrode and said second electrode, wherein said surface portions of said semiconductor layer receive incident light predominantly in the surface of said semiconductor layer.