【作者】 王丽娟；

【导师】 李梅； 邵喜斌；

【作者基本信息】 长春理工大学 ， 微电子学与固体电子学， 2004， 硕士

【摘要】 薄膜晶体管（Thin Film Transistor的英文缩写是TFT）是近年来显示器上广泛使用的器件，其中a-Si：H TFT（hydrogenateld amorphous siliconTFT非晶硅薄膜晶体管）是发展的主流，常用作有源矩阵液晶显示器的开关元件。随着a-Si：H TFT的广泛应用，其模型的建立就成为非常重要的课题。精确的a-Si：H TFT模型在SPICE模拟中是非常重要的。在国内外已经发表了许多关于a-Si：H TFT物理特性及模型的文章，但仍然不能满足今天先进LCD模拟的需要。 为配合国家十五“863”计划项目“高品质大尺寸a-Si：H TFT-OLED技术研究”工作，本论文重点进行了a-Si：H TFT SPICE模型的研究工作。 本文以底栅结构背沟道阻挡型a-Si：H TFT器件为基础，测试了电流电压（I-V）特性和电容电压（C-V）特性。从电容电压曲线中提取了a-Si：H的掺杂浓度、固定电荷密度、界面态密度等工艺参数。分析了a-Si：H TFT的局域态、亚阈值导电、泄漏电流、表面迁移率调制、栅源和栅漏电容对频率的依赖性，温度特性及应力对阈值电压的影响。本论文以MOSFET为模型基础，对I-V特性进行了理论分析，建立了线性区、饱和区的漏极电流模型，重点建立了精确的亚阈值前区、亚阈值后区漏极电流和截止区的泄漏电流模型。同时：本论文以MIS结构的电容为理论基础，建立了a-Si：HTFT的MIS结构依赖于偏压和频率的电容模型，并提取了阈值电压V_TO、迁移率μ0等模型参数。用C语言编程模拟了I-V和C-V特性，测试数据与模拟数据拟合得很好，优于以往的a-Si：H TFT SPICE模型。本论文建立的模型适用于不同工艺结构的a-Si：H TFT器件，对TFT的设计者具有较高的指导价值。更多还原

【Abstract】 TFT（ Thin Film Transistor ）is widely used for displays. The main TFT is a-Si:H TFT which is switching device of active matrix liquid crystal display. With the wide application of a-Si:H TFT, the establishment of its models becomes a very important question for study. Accurate a-Si:H TFT models are required for SPICE simulators. Several papers have already been published regarding the physics and the models of a-Si:H TFT, but they are insufficient for today’s advanced LCD simulations.This thesis mainly studied SPICE model for a-Si:H TFT, which is a part of national "863" project, "Study of Large Size and high quality a-Si TFT-OLED technology". The analysis and models are applicable to the simulation of today’s optical characterizations of Flat-Panel-Displays.In this thesis, the new models of a-Si:H TFT are established for SPICE, on the basis of inverted-stagger structure a-Si:H TFT of back channel stopped types. Current-voltage and capacitance-voltage are also tested. From the capacitance curve, the process parameters are extracted, such as dopant concentration, fixed charge density, interface state, etc. This paper analyzed localized state, sub-threshold current, off-leakage current, the field effect mobility, bias- and frequency-dependent capacitance, the threshold voltage change with voltage stress and device temperature, etc. This thesis focuses on the establishment of new drain current models in the linear region, the saturation region, the forward and reverse sub-threshold region, and new off-leakage current models in the off region on based of MOSFET model. In addition, the precise bias- and frequency-dependent MIS capacitance models are established. Some model parameters are extracted, such as threshold voltage(V_TO), mobility（μ0） etc. Simulation results by using these models and parameters show good agreement between measured and simulated data. The models are applicable to the a-Si:H TFT devices with different process structures. The modeling procedure is useful to TFT designers.更多还原