基于表面势的非晶氧化锌薄膜晶体管漏电流模型的研究
发布时间：2018-09-14 19:55
【摘要】：非晶氧化锌薄膜晶体管(a-Zn O TFTs)在有源矩阵液晶显示(AMLCD)器件、固体图像传感器、化学传感器等应用中发挥越来越重要的作用。由于a-Zn O器件较氢化非晶硅(aSi:H)器件呈现出更复杂的电学特性,而且a-Zn O器件比a-Si:H器件具有更高的迁移率;因此,合理地构建a-Zn O TFTs的物理模型也变得越来越重要,特别是阐明a-Zn O TFTs漏电流的物理机制,给出与器件特性相一致的函数关系,可为a-Zn O TFTs显示器件的制备和电路仿真提供理论依据。本文的研究目标是详细地对a-Zn O TFTs的物理机制进行系统研究,并在对a-Zn O TFTs迁移率讨论的基础上,基于表面势对a-Zn O TFTs的漏电流特性建立紧凑模型,并使该模型具备嵌入电路仿真器的条件。基于泊松方程和高斯定理,采用非迭代算法,在考虑a-Zn O TFTs带隙能态的指数带尾态和深能态的完整分布条件下,解析地建立了a-Zn O TFTs的表面势紧凑模型。本文的表面势解析求解,是根据数学变换和Lambert W函数,采用有效电荷密度方法,建立a-Zn O TFTs表面势的一种非迭代求解新算法。与数值迭代算法的计算结果进行比较,该表面势解析算法的绝对误差低至-510 V数量级,且提高了计算效率;此算法避免了迭代求解,可有效减少仿真时间,为模型嵌入电路仿真器提供了实现条件。基于上述非迭代表面势算法,可以建立a-Zn O TFTs的漏电流方程。通过与不同漏源电压和栅源电压下a-Zn O TFTs器件的实验数据进行对比,得出漏电流模型的输出特性与转移特性曲线,进而验证了本文漏电流模型的有效性和正确性。此外,为进一步研究a-Zn O TFTs的漏电流特性,本文通过对幂律函数迁移率的分析和对有效沟道迁移率的推导,以及对这两种迁移率下器件漏电流方程的误差分析,得出适用于本文漏电流模型的最优迁移率方程。综上所述,本文提出的a-Zn O TFTs直流模型,是以a-Zn O TFTs工作的物理机制作为基础,并以表面势为函数的方程进行表征。模型参数与器件参数之间的关系简单,模型能够依据现有实验数据进行较好的拟合;模型需要的计算量少,模型的数学表达式及其一阶导数连续,因此可满足嵌入电路仿真器的条件。
[Abstract]:Amorphous ZnO thin film transistors (a-Zn O TFTs) play an increasingly important role in the applications of active matrix liquid crystal display (AMLCD) devices solid image sensors and chemical sensors. Since a-Zn O devices exhibit more complex electrical properties than hydrogenated amorphous silicon (aSi:H) devices, and a-Zn O devices have higher mobility than a-Si:H devices, it is becoming more and more important to reasonably construct the physical model of a-Zn O TFTs. In particular, the physical mechanism of leakage current of a-Zn O TFTs is clarified, and the functional relation consistent with the characteristics of the device is given, which can provide a theoretical basis for the fabrication and circuit simulation of a-Zn O TFTs display devices. The purpose of this paper is to study the physical mechanism of a-Zn O TFTs in detail, and based on the discussion of a-Zn O TFTs mobility, a compact model of leakage current characteristics of a-Zn O TFTs based on surface potential is established. The model has the condition of embedded circuit simulator. Based on Poisson equation and Gao Si theorem, the surface potential compact model of a-Zn O TFTs is established analytically under the condition of complete distribution of exponential band tail state and deep energy state of a-Zn O TFTs bandgap energy state by using non-iterative algorithm. Based on the mathematical transformation and Lambert W function, a new non-iterative algorithm for solving a-Zn O TFTs surface potential is established by using the effective charge density method. Compared with the results of numerical iterative algorithm, the absolute error of the algorithm is as low as -510V, and the computational efficiency is improved, the algorithm avoids iterative solution and can effectively reduce the simulation time. The implementation condition of the model embedded circuit simulator is provided. Based on the above non-iterative surface potential algorithm, the leakage current equation of a-Zn O TFTs can be established. By comparing with the experimental data of a-Zn O TFTs devices under different drain voltage and gate source voltage, the output characteristics and transfer characteristic curves of the leakage current model are obtained, and the validity and correctness of the leakage current model in this paper are verified. In addition, in order to further study the leakage current characteristics of a-Zn O TFTs, through the analysis of the mobility of power law function and the derivation of effective channel mobility, as well as the error analysis of leakage current equation of devices under these two kinds of mobility, The optimal mobility equation applicable to the leakage current model is obtained. To sum up, the a-Zn O TFTs DC model proposed in this paper is based on the physical mechanism of a-Zn O TFTs work and is characterized by the equation with surface potential as a function. The relationship between the model parameters and the device parameters is simple, the model can fit well according to the existing experimental data, the model needs less calculation, the mathematical expression of the model and its first derivative are continuous. Therefore, the condition of embedded circuit simulator can be satisfied.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN321.5
本文编号：2243716
[Abstract]:Amorphous ZnO thin film transistors (a-Zn O TFTs) play an increasingly important role in the applications of active matrix liquid crystal display (AMLCD) devices solid image sensors and chemical sensors. Since a-Zn O devices exhibit more complex electrical properties than hydrogenated amorphous silicon (aSi:H) devices, and a-Zn O devices have higher mobility than a-Si:H devices, it is becoming more and more important to reasonably construct the physical model of a-Zn O TFTs. In particular, the physical mechanism of leakage current of a-Zn O TFTs is clarified, and the functional relation consistent with the characteristics of the device is given, which can provide a theoretical basis for the fabrication and circuit simulation of a-Zn O TFTs display devices. The purpose of this paper is to study the physical mechanism of a-Zn O TFTs in detail, and based on the discussion of a-Zn O TFTs mobility, a compact model of leakage current characteristics of a-Zn O TFTs based on surface potential is established. The model has the condition of embedded circuit simulator. Based on Poisson equation and Gao Si theorem, the surface potential compact model of a-Zn O TFTs is established analytically under the condition of complete distribution of exponential band tail state and deep energy state of a-Zn O TFTs bandgap energy state by using non-iterative algorithm. Based on the mathematical transformation and Lambert W function, a new non-iterative algorithm for solving a-Zn O TFTs surface potential is established by using the effective charge density method. Compared with the results of numerical iterative algorithm, the absolute error of the algorithm is as low as -510V, and the computational efficiency is improved, the algorithm avoids iterative solution and can effectively reduce the simulation time. The implementation condition of the model embedded circuit simulator is provided. Based on the above non-iterative surface potential algorithm, the leakage current equation of a-Zn O TFTs can be established. By comparing with the experimental data of a-Zn O TFTs devices under different drain voltage and gate source voltage, the output characteristics and transfer characteristic curves of the leakage current model are obtained, and the validity and correctness of the leakage current model in this paper are verified. In addition, in order to further study the leakage current characteristics of a-Zn O TFTs, through the analysis of the mobility of power law function and the derivation of effective channel mobility, as well as the error analysis of leakage current equation of devices under these two kinds of mobility, The optimal mobility equation applicable to the leakage current model is obtained. To sum up, the a-Zn O TFTs DC model proposed in this paper is based on the physical mechanism of a-Zn O TFTs work and is characterized by the equation with surface potential as a function. The relationship between the model parameters and the device parameters is simple, the model can fit well according to the existing experimental data, the model needs less calculation, the mathematical expression of the model and its first derivative are continuous. Therefore, the condition of embedded circuit simulator can be satisfied.
【学位授予单位】：暨南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN321.5
【参考文献】
相关博士学位论文 前1条
1 张杰;氧化物半导体薄膜晶体管的若干研究[D];浙江大学;2014年
，本文编号：2243716
本文链接：https://www.wllwen.com/kejilunwen/dianzigongchenglunwen/2243716.html
