具有漏端Offset的非晶铟镓锌氧化物薄膜晶体管的特性及开态电流模型

Characterization and On-Current Model of Drain Offset a-IGZO Thin Film Transistors

本文研究了具有不同漏端Offset长度(LDO)的非晶铟镓锌氧化物(Amorphous Indium-Gallium-Zinc-Oxide,a-IGZO)薄膜晶体管(Thin-Film Transistors,TFT)的电学特性,发现器件的阈值电压(Vth)、亚阈值摆幅(SS)、关态电流(Ioff)与LDO无明显依赖关系。通过分析漏端Offset区域的电流与电压关系,发现其遵循欧姆定律,由此提取出漏端Offset区域电阻(RDO)。研究发现RDO与LDO成幂函数关系且幂次随栅源电压(VGS)的增加而增加,由此我们提出RDO的经验模型,同时利用此模型得到漏端Offset a-IGZO TFT的开态电流模型并通过与电流-电压曲线拟合得以验证。

We study the effect of drain Offset lengths(LDO)on the performance of amorphous-indium-gallium-zinc-oxide(a-IGZO)thin-film transistors(TFTs),the threshold voltage(Vth)and sub-threshold swing(SS)and off-current(Ioff)remain relatively independent of the LDO variation.By analyzing the relationship between current and voltage in the Offset region,it is found that it follows the Ohm’s law.The resistance(RDO)in the drain-offset region is extracted by using Ohm’s law,it is found that RDO and LDOpresent the power function relation and the exponent of power function increases with the increase of gate-to-source voltage(VGS).Based on this,we propose an empirical model of RDO,and use this model to obtain the on-current model of drain Offset TFTs,which is verified by fitting the current-voltage curves.