PHOTODIODE

PROBLEM TO BE SOLVED: To provide a photodiode, which has a light-receiving surface, which can be electrically split, and can be optically aligned. SOLUTION: A plurality of N-type layers 12 are provided in a P-type substrate 18 in a prescribed mode, P-N junctions are formed and light-receiving surfaces are respectively formed. P-type layers 20 for separating the layers 12 from each other are respectively formed between the layers 12. In the case where a voltage is applied to gate electrodes 14, the layers 20 between the layers 12 are turned into N-type layers by a field inversion. As a result, the fellow adjacent N-type layers 12 are connected with each other and function as one light-receiving surface. Thereby, when a voltage is applied to the electrodes 14 located at positions other than a position, where the light-receiving surface is wanted to split, all of the layers 12 result in being connected with each other excepting the layer 12, which is wanted to split, and the light- receiving surface of a photodiode 10 can be electrically split.