低掺杂多晶硅TFT阈值电压的确定和提取

通过对低掺杂多晶硅薄膜晶体管表面势的分析, 建立基于物理过程的阈值电压模型。当其表面势偏离亚阈值区时沟道电流将迅速增加,将此时所对应的栅压定义为阈值电压。基于多晶硅薄膜的陷阱态密度为单指数分布,通过对表面势进行化简与求解,建立了解析的阈值电压模型。器件数值仿真结果表明，采用二次导数法所提取的阈值电压值与本文所提出的阈值电压模型较好的匹配。

Threshold voltage definition and extraction for lightly doped polysilicon thin film transistors

For lightly doped polysilicon thin film transistors, the channel current increases quickly when its surface potential deviates from the sub-threshold region. So it can be considered that the corresponding gate voltage is the threshold voltage. Taking the single exponential distribution of trap states density into consideration, explicit simplification and calculation of surface potential is derived, and the analytical threshold voltage model is presented. The results of device numerical simulation indicate that the threshold voltage extracted by the second-derivative method matches perfectly with the threshold voltage model presented in this paper.