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(fā)布時(shí)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(xué)傳感器等應(yīng)用中發(fā)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(xiàn)出更復(fù)雜的電學(xué)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(gòu)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(jī)制,給出與器件特性相一致的函數(shù)關(guān)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(jù)。本文的研究目標(biāo)是詳細(xì)地對a-Zn O TFTs的物理機(jī)制進(jìn)行系統(tǒng)研究,并在對a-Zn O TFTs遷移率討論的基礎(chǔ)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。基于泊松方程和高斯定理,采用非迭代算法,在考慮a-Zn O TFTs帶隙能態(tài)的指數(shù)帶尾態(tài)和深能態(tài)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(jù)數(shù)學(xué)變換和Lambert W函數(shù),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(shù)值迭代算法的計(jì)算結(jié)果進(jìn)行比較,該表面勢解析算法的絕對誤差低至-510 V數(shù)量級,且提高了計(jì)算效率;此算法避免了迭代求解,可有效減少仿真時(shí)間,為模型嵌入電路仿真器提供了實(shí)現(xiàn)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(shí)驗(yàn)數(shù)據(jù)進(jìn)行對比,得出漏電流模型的輸出特性與轉(zhuǎn)移特性曲線,進(jìn)而驗(yàn)證了本文漏電流模型的有效性和正確性。此外,為進(jìn)一步研究a-Zn O TFTs的漏電流特性,本文通過對冪律函數(shù)遷移率的分析和對有效溝道遷移率的推導(dǎo),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(yōu)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(jī)制作為基礎(chǔ),并以表面勢為函數(shù)的方程進(jìn)行表征。模型參數(shù)與器件參數(shù)之間的關(guān)系簡單,模型能夠依據(jù)現(xiàn)有實(shí)驗(yàn)數(shù)據(jù)進(jìn)行較好的擬合;模型需要的計(jì)算量少,模型的數(shù)學(xué)表達(dá)式及其一階導(dǎo)數(shù)連續(xù),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(xué)位授予單位】：暨南大學(xué)
【學(xué)位級別】：碩士
【學(xué)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(xué)位授予單位】：暨南大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：TN321.5
【參考文獻(xiàn)】
相關(guān)博士學(xué)位論文 前1條
1 張杰;氧化物半導(dǎo)體薄膜晶體管的若干研究[D];浙江大學(xué);2014年
，本文編號：2243716
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