中文摘要：

针对氢化非晶硅薄膜晶体管中的输出电流不饱和现象，采用半导体器件模拟软件对非晶硅薄膜晶体管的输出特性进行了数值仿真，并探讨了不饱和输出电流的产生机理．仿真结果表明：在长沟道器件中，随着漏源电压的增加，体电流的传输机制将转变为空间电荷限制传导，此即为器件中产生不饱和输出电流的主要原因；而在短沟道器件中，还需要同时考虑漏致势垒降低效应的影响．

英文摘要：

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.