Infrared photodetector formed by array of semiconductor elements shaped to have increased electron diffusion area

摘要

A photodetector has a substrate made of a first semiconductor type and having a surface, and a plurality of independent diffusion regions formed in the surface of the substrate and made of a second semiconductor type which is opposite to the first semiconductor type so that a pn junction is formed between the substrate and each diffusion region. Discrete photosensitive areas are formed by each of the diffusion regions and blind areas are formed between adjacent ones of the photosensitive areas when a bias voltage is applied across each pn junction, where each of the photosensitive areas have the same area. At least predetermined ones of the diffusion regions have a main part and at least one auxiliary part which is electrically coupled to the main part, and the auxiliary part is provided in a region on the surface of the substrate towards a corresponding one of the blind areas relative to the main part, so that the blind area is reduced by a part of the photosensitive area formed by the auxiliary part of the diffusion region.