"Progress In Schottky-Barrier IR Imagers"

Abstract

SUMMARYSchottky- barrier focal plane arrays are the only infrared imagers that are fabricatedby the well established silicon VLSI process. Therefore, at the present time they repre-sent the most mature technology for large -area high- density focal plane arrays for manySWIR (1 to 3 pm) and MWIR (3 to 5 pm) applications.1 -27 PtSi Schottky- barrier detectors(SBDs) were developed for operation in the MWIR band at a temperature of 77 to 80K. TheseSBDs can be designed for operation at 77K with a dark current density in the range of 1.0 to 20 nA /cm2. Pd2Si SBDs were developed for operation with passive cooling at 120K in theSWIR band. Although the PtSi SBDs have rather low quantum efficiency (0.5 to 1.0% at 4.0pm), however, because of very low readout noise, the IR -CCD imagers with PtSi SBDs arecapable of 300K thermal imaging with a noise equivalent (NEAT) of less than 0.1K. The noise floor of the SBD arrays is limited by the SBD dark current shot noise.With the support of RADC, Hanscom AFB, MA, RCA Laboratories developed a 160 x 244 -element PtSi Schottky- barrier IR -CCD imager with 80 (H) x 40 (V) -pm2 pixels and 39% fillfactor for operation at 30 frames /s with standard TV field interlace.27 Excellent qualitythermal imaging and NEAT of less than 0.1K were demonstrated with this staring imager foroperation at 30 frames /s, with f/2.3 optics, and with an additive type (one point) pixelcorrector which averages 16 reference frames to produce the correction video signal.A brief review of the progress in the development of Schottky- barrier focal planearrays will be complemented by a video tape demonstration of the performance of the 160 x