N-channel polysilicon thin film transistors as gamma-ray detectors

Abstract

N-type thin film transistors (TFTs) fabricated with fluorinated and hydrogenated polysilicon were exposed to gamma radiation to a cumulative dose up to 1200 Gy(Si). During irradiation, the gate electrode was biased with a positive voltage up to 4.8 V. The effect of irradiation on the electrical characteristics of the devices was monitored after the irradiation steps and in a prolonged period after irradiation. The main monitoring parameter was the threshold voltage which was found to have linear dependence on irradiation dose. This, together with obtained low fading, suggests that thin transistors have potential as radiation dosimeters.