PHOTOCONDUCTIVE IMPEDANCE-MATCHED INFRARED DETECTOR WITH HETEROJUNCTION BLOCKING CONTACTS

A photoconductive isotype heterojunction impedance-matched infrared detector has blocking contacts which are positioned on the bottom side of the detector. The blocking contacts prevent transfer of minority carriers from the active region of the detector, thereby extending the lifetime of these carriers. The detector is formed by first fabricating an active layer followed by an isotype blocking layer on a growth substrate. These layers are etched and appropriate passivation layers and contacts are applied. A mechanical supporting substrate is applied to the detector and the growth substrate is removed. Etch stop holes are formed which extend into the active layer of the detector. A precision thickness of the active layer required in an impedance-matched detector design is produced by thinning the active layer in an etching process until the surface of the active layer reaches the etch stop hole. The detector produced in accordance with the structure and methods set forth herein is highly suitable for use in an array of such detectors which can form an infrared focal plane array.