Submicron thin-film amorphous silicon photoconductive light sensors

Advanced photodetector and imaging array applications require photosensors with ever-decreasing dimensions to achieve high spatial resolution. Thin film, intrinsic hydrogenated amorphous silicon submicron wire, gap, and square photoconductors, in which the minimum device dimension has been scaled down to a minimum of 60 nm, maintain the 105 photo-to-dark conductivity ratio of their large-area (mm-size and above) counterparts at a carrier generation rate of 1021 cm−3 s−1. The devices are fabricated using electron beam lithography. Ohmic behavior is observed in all devices independently of their device dimension. The dark conductivity is independent of the critical dimension of the photoconductor, while the photoconductivity increases sublinearly with decreasing device dimensions.