Patent ID: 7265740

Claim:
An optical sensor diode, comprising: a semiconductor layer including a p region to which p-type impurities are injected, an n region to which n-type impurities are injected, and an i region with a lower impurity concentration than those of the p and n regions; an anode electrode connected to the p region; a cathode electrode connected to the n region; a gate electrode provided above the i region with an insulating film interposed therebetween; a first electrostatic capacity element formed between the gate electrode and the anode electrode; and a second electrostatic capacity element formed between the gate electrode and the cathode electrode, wherein the first electrostatic capacity element is formed of a polysilicon film in the same layer as the semiconductor layer and an upper electrode common to the gate electrode, which is provided so as to overlap the polysilicon film; and the second electrostatic capacity element is formed of a polysilicon film in the same layer as the semiconductor layer and an upper electrode common to the gate electrode, which is provided so as to overlap the polysilicon film.