a-Si∶H TFT亚阈值区SPICE模型的研究  

SPICE Model in Sub-threshold Region for a-Si:H TFT

作　　者：邵喜斌[1] 王丽娟[2] 李梅[3] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]吉林北方彩晶数码电子有限公司,吉林长春130033 [3]长春理工大学高功率半导体激光国家重点实验室,吉林长春130022

出　　处：《液晶与显示》2005年第4期267-272,共6页Chinese Journal of Liquid Crystals and Displays

基　　金：国家"863"十五计划资助项目(No.2004AA303560)

摘　　要：研究了将非晶硅薄膜晶体管(a-Si∶HTFT)在电路模拟程序(SPICE)中使用的亚阈值区模型,将亚阈值区分为亚阈值前区和亚阈值后区并建立了模型,对比了不同模型下的模拟结果,发现亚阈值区的TFT特性依赖于材料性质,而且亚阈值前区和亚阈值后区的特性受栅源电压VGS和漏源电压VDS的影响,呈指数变化。提出的新模型考虑了前界面态、后界面态、局域态、材料及制作工艺等因素,体现了该区域电流对漏源电压VDS强烈的依赖关系。使用新模型对实验数据的拟合结果优于以往的模型,能够比较精确地模拟亚阈值区的特性,可用来预测a-Si∶HTFT的性能,对TFT阵列的模拟设计具有重要价值。The models for simulation program with integrated circuit emphasis （SPICE） in the sub-threshold I-V region of hydrogenated amorphous silicon thin film transistor （a-Si：H TFT） were investigated.The sub-threshold region was divided into a forward sub-threshold region and a reverse sub-threshold region. This paper focuses on the establishment of new model which can describe the I-V characteristics of a-Si： H TFT accurately in the forward sub-threshold region and the reverse sub-threshold region. It was found that the 1-VcharacteristicsofTFT rely on the material＇s quality, and models of the forward and reverse sub-threshold region were affected by gate-source voltage （Vcs） and drain-source voltage （VDs）. The effect follows an exponential function. The new a-Si： H TFT models were developed to simulate important a-Si： H TFT characteristics such as forward sub-threshold current, reverse sub-threshold current, by considering the effect of electron distribution by Vds. and the current change due to front interface states, back interface states, localized states, material, process, and so on. Simulation results using these new models showed better agreement with measured data than those presented by other researchers. These models and the modeling process are practical for TFT simulations. This analysis is useful to active matrix LCD designers for evaluating and predicting the performance of a-Si：H TFT array.

关 键 词：a—Si:H TFT SPICE模型 亚阈值区 

分 类 号：TN321.5[电子电信—物理电子学]