Abstract:

In order to overcome the unsaturated output current of hydrogenated amorphous-silicon thin-film transistors （ a-Si ： H TFTs）, the output characteristics of a-Si ： H TFTs are numerically simulated by using the semiconductor device simulation software, and the generation mechanism of the unsaturated output current is discussed. Simulated results show that, in long-channel semiconductor devices, the conduction of bulk current changes into a space charge-limited mode due to the increase of drain-source voltage, which is the main reason for the unsaturated output current, and that, in short-channel semiconductor devices, the drain-induced barrier lowering effect should be meanwhile considered.

Key words: amorphous silicon, thin-film transistor, unsaturated output current, numerical simulation, space charge-limited conduction, drain-induced barrier lowering