Image sensor

Abstract

Abstract PURPOSE:To make large the ratio of resistance values under dark period and light irradiation period and also suppress dispersion of such ratio by providing electrodes for applying bias voltage through the insulation layers at the rear surface of Si layers provided opposite to each other in a sensor in which the opposed electrodes are provided through an interval on the surface of an amorphous Si layer and said opposed electrodes detect change of resistance value in accordance with the amount of light irradiated. CONSTITUTION:The electrodes 11 for applying bias voltage are formed at the center surface of a substrate 2, these are surrounded by an insulation layer 10, and the photo-conductive layer 1 made of an amorphous Si is deposited thereon including such insulation layer. The electrodes 3, 4 opposed through an interval 12 corresponding to the electrode 11 are formed on the area extending from such photoconductive layer to the substrate 2 and the entire part thereof is covered with a protection layer 5. Thereby, the ratio of resistance values under the light irradiating condition and dark condition becomes large and as a result, noise can be reduced and dynamic range can be expanded. Moreover, a highly reliable sensor showing less change of resistance value ratio can be obtained by allowing bias voltage to change in accordance with change of temperature.

Inventors

• 👤 Tsutomu Ishida
• 👤 力 石田

Bibliographic Details