INFRARED-SPECTRUM PHOTODETECTOR Russian patent published in 1996 - IPC

FIELD: electronic engineering; multielement and single-element extrinsic-conductivity photodetectors sensitive in infrared spectrum. SUBSTANCE: photodetector has substrate made of semiconductor compensated by deep multicharge impurity creating twice negative charged levels. Both sides of photodetector carry conducting buses built up of contact layer on substrate and deposited metal affording electric contact with substrate. Contact layer, as distinct from prototype, is formed from two regions at 300 K with different concentration of impurity enriching this layer. First region has maximum concentration so that it is twice as large or equal to diffusion length of carriers. Second region with impurity concentration is enriched by 1 or 2% higher than concentration of small impurities in substrate. Width of this region should be greater than length of carrier shielding at fine impurity compensation. Region of n⁺-n(p⁺-p) junction that possesses injecting properties appears in contact region during photodetector cooling. This junction incorporates fine impurity compensation plane possessing utmost shielding length of carriers injected from contact. Second region affords separation of electric contact to compensated semiconductor into two contacts performing different functions: nickel film and enriched substrate region contact that is resistive contact; second region and substrate contact which is injecting contact. EFFECT: improved design. 2 cl, 2 dwg, 3 tbl