基于表面势的氢化非晶硅薄膜晶体管直流特性研究

DC characteristic research based on surface potential for a-Si:H thin-film transistor

基于表面势模型,在同时考虑深能态和带尾态分布下,采用简化的费米-狄拉克函数计算得到统一的定域态模型,并利用有效特征温度的概念,推导出a-Si:H TFT统一的电流-电压(I-V)模型.该模型可不分区地描述包括亚阈值区、线性区以及饱和区等a-Si:H TFT的所有工作区域.与实验得到的I-V特性进行比较表明,本模型能够准确地描述a-Si:H TFT的各个工作区的电流电压特性.

In this paper, based on the surface potential model, taking into account both the deep and tail state distributions simultaneously, and using the simplified Fermi-Dirac function, a unified local-state model is obtained. Using the effective characteristic temperature, the unified current-voltage （l-V） model for a-Si ： H thin-film transistor a-Si ： H TFT is developed. This model can describes all operating regions including subthreshold region, linear area and saturated zone through a single equation. By comparison with the experimental data, it is shown that this model can accurately describe the current voltage characteristic of the a-Si ： H TFT.