MULTICOMPONENT PHOTODETECTOR WITH LONG-WAVE ABSORPTION EDGE Russian patent published in 2001 - IPC

FIELD: semiconductor engineering; photodetector modules for night viewing devices, thermal imagers, gas analyzers. SUBSTANCE: device whose absorption-edge wavelength is up to 7 mcm has high-resistance p-type silicon substrate with electrode and P⁺ contact layer on exposure side and mesa-structure with P⁺ photo-active absorption layer, P⁺⁺ contact layer, and aluminum electrode on other side; thin transparent indium and tin oxide layer, 0.2-0.5 mcm thick, is evaporated on P⁺⁺ contact layer on exposure side to function as electrode; dope concentration in P⁺⁺ contact layers is N_p~ 1•10¹⁹cm^-3; provided between P⁺⁺ contact layer of exposure side and p substrate is doped P⁺ layer with N_p~ 10¹⁷•10¹⁸cm^-3, 3-5 mcm thick, that forms, together with p substrate and p⁺⁺ contact layer, (p-p⁺-p⁺⁺) potential barrier that enables blocking dark conduction; mesa-structures and thin photo-active P⁺ layer with dope concentration N_p~(5•7)•10¹⁹cm^-3 made on other side of substrate are of such depth and thickness, respectively, that P⁺ photo-active absorption layer is fully isolated by mesa-structure and its dope concentration is same as that of substrate at depth smaller than mesa-structure depth. Isolation attained in this way is higher than 95%. Aluminum electrode is deposited onto entire mesa-structure surface. EFFECT: enhanced isolation. 2 cl, 3 dwg