基于表面勢的非晶氧化鋅薄膜晶體管漏電流模型的研究
發布時間：2018-09-14 19:55
【摘要】：非晶氧化鋅薄膜晶體管(a-Zn O TFTs)在有源矩陣液晶顯示(AMLCD)器件、固體圖像傳感器、化學傳感器等應用中發揮越來越重要的作用。由于a-Zn O器件較氫化非晶硅(aSi:H)器件呈現出更復雜的電學特性,而且a-Zn O器件比a-Si:H器件具有更高的遷移率;因此,合理地構建a-Zn O TFTs的物理模型也變得越來越重要,特別是闡明a-Zn O TFTs漏電流的物理機制,給出與器件特性相一致的函數關系,可為a-Zn O TFTs顯示器件的制備和電路仿真提供理論依據。本文的研究目標是詳細地對a-Zn O TFTs的物理機制進行系統研究,并在對a-Zn O TFTs遷移率討論的基礎上,基于表面勢對a-Zn O TFTs的漏電流特性建立緊湊模型,并使該模型具備嵌入電路仿真器的條件�；诓此煞匠毯透咚苟ɡ�,采用非迭代算法,在考慮a-Zn O TFTs帶隙能態的指數帶尾態和深能態的完整分布條件下,解析地建立了a-Zn O TFTs的表面勢緊湊模型。本文的表面勢解析求解,是根據數學變換和Lambert W函數,采用有效電荷密度方法,建立a-Zn O TFTs表面勢的一種非迭代求解新算法。與數值迭代算法的計算結果進行比較,該表面勢解析算法的絕對誤差低至-510 V數量級,且提高了計算效率;此算法避免了迭代求解,可有效減少仿真時間,為模型嵌入電路仿真器提供了實現條件�；谏鲜龇堑砻鎰菟惴�,可以建立a-Zn O TFTs的漏電流方程。通過與不同漏源電壓和柵源電壓下a-Zn O TFTs器件的實驗數據進行對比,得出漏電流模型的輸出特性與轉移特性曲線,進而驗證了本文漏電流模型的有效性和正確性。此外,為進一步研究a-Zn O TFTs的漏電流特性,本文通過對冪律函數遷移率的分析和對有效溝道遷移率的推導,以及對這兩種遷移率下器件漏電流方程的誤差分析,得出適用于本文漏電流模型的最優遷移率方程。綜上所述,本文提出的a-Zn O TFTs直流模型,是以a-Zn O TFTs工作的物理機制作為基礎,并以表面勢為函數的方程進行表征。模型參數與器件參數之間的關系簡單,模型能夠依據現有實驗數據進行較好的擬合;模型需要的計算量少,模型的數學表達式及其一階導數連續,因此可滿足嵌入電路仿真器的條件。
[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.
【學位授予單位】：暨南大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN321.5
本文編號：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.
【學位授予單位】：暨南大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN321.5
【參考文獻】
相關博士學位論文 前1條
1 張杰;氧化物半導體薄膜晶體管的若干研究[D];浙江大學;2014年
，本文編號：2243716
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