Field-effect photo-transistor

A field-effect photo-transistor, being a three-terminal photosensing electrical device, based on integrated metal oxide semiconductor (MOS) technology. The device features a high output impedance which makes it particularly suitable as a photosensor for active pixel imaging arrays. Unlike the bipolar photo-transistor, which is a device well known in the art, the field-effect phototransistor is more compatible with MOS VLSI (Very Large Scale Integration) technology by inherently being a unipolar type device. Active pixel imaging arrays based on the disclosed invention can be integrated on the same semiconductor substrate with conventional digital or mixed signal processing functions to produce single-chip image processors for video or still picture cameras.