InAs Photodiode Mosaic.

InAs diode array infrared vidicon targets, which can be operated in a charge-storage mode via electron beam scanning, have been developed and demonstrated. The basic steps include 1 production of low leakage current array diodes, 2 effective target surface passivation to prevent the beam from landing on the n-substrate surface, and 3 deposition of a charge removing layer on the passivated dielectric surface. Reverse-biased InAs photodiodes yield an internal current gain by carrier impact ionization. The ionization rate for electrons is much greater than that for holes. Because of the low diode dark current, the operation of InAs photovoltaic detectors has led to a BLIP performance, approaching the theoretical limit. A preliminary study of the InAs MIS structure, performed to solve various surface-related device problems, has led to an interesting new type of infrared sensing device, the InAs MIS photodetector. Some experimental results for this new photodetector are presented here. It is recommended that InAs solid-state infrared imagers, using the surface charge-coupling concept, be developed for practical devices. Author