导　　师： 万青

学科专业： 070205

授予学位： 硕士

作　　者： ;

机构地区： 湖南大学

摘　　要： 薄膜晶体管/(TFTs Thin Film Transistors/)作为一种固态电子开关器件,在传感器、平板显示、集成电路等领域中有着广泛的应用。近些年来,随着透明电子学的发展,透明氧化物TFT由于透明性、与柔性衬底兼容、良好的电学性能广受研究者的青睐,被认为将取代传统非晶硅/(a-Si:H/)TFT而成为主流。 本课题研究为ITO薄膜晶体管。ITO /(氧化铟掺锡/)薄膜具有良好的透光性、高载流子浓度/(10~/(20/)~10~/(21/)cm~/(-3/)/)及迁移率/(10~30cm~2//Vs/)、良好的物理化学稳定性,并且制备方法很多,非常适合作为TFT的沟道层。传统的氧化物TFT存在工作电压大的缺点,我们这里制备的ITO TFT工作电压降到了0.8V以下,并且在可见光范围内透明。 本论文分为了四个部分;第一部分综述了薄膜晶体管的基本理论知识,包括TFT的工作原理、电学理论基础、发展历程等,另外介绍了ITO薄膜的基本性质。第二部分分析了TFT制备材料的选择,以及联系实验室设备讲述了TFT的制备工艺、电学性能检测方法。第三部分和第四部分为实验部分。 第三部分;我们实验制备了底栅顶接触的ITO薄膜晶体管。ITO TFT工作在1.5V的工作电压下,阈值电压为0.32V、饱和场效应迁移率13.5cm~2//Vs、电流开关比为1.2×10~6、亚阈值斜率为130mV//decade。 第四部分;我们将沟道层和电极层采用一步掩膜工艺制备完成,制备了0.8V工作电压的ITO薄膜晶体管。为了实现0.8V的超低工作电压,我们通过将二氧化硅在浓度为43.5/%氯化锂溶液中浸泡处理,二氧化硅薄膜中进入大量的离子以形成固态电解质,以这种电解质作为栅介质,在器件中能形成超强的双电荷层效应,具有高达9.2μF//cm~2的单位电容。ITO TFTs的电学性能为;迁移率为28.4 cm~2//Vs,阈值电压为-0.16 V,电流开关比为1×10~7,亚阈值斜率为98 mV//decade。 良好的实验结果表明了;我们所制备的ITO� Thin film transistors as electronic switching device play an important role in the fields of sensors, flat panel display and integrated circuit. In recent years, because of their high transparency, compatibility with flexible substrates, good electrical properties, transparent oxide-based TFTs have become a hot shot. It is widely regarded that transparent oxide-based TFTs will replace traditional a-Si:H TFT and become the mainstream in the next few years. In this thesis, my research is about ITO TFTs. The advantages of ITO film are good light transmission, high carrier concentration/(10~/(20/)~10~/(21/)cm~/(-3/)/) , high carrier mobility/(10~30cm~2//Vs/), good physical and chemical stability. In addition, they can be deposited by a variety of methods. All the advantages of ITO film indicate that it suit for the channel materials for transparent TFT. However, large operating voltage is a weak point for traditional transparent TFT. In my work, we prepared ITO TFTs operating at 0.8V, and they have good light transmission. My thesis includes four parts. The first part gives the basic theory of TFTs, such as working mechanism, electrical theory and basic properties. In the second part, the preparing technology, performance testing methods of ITO TFTs are presented. In the third part, ITO TFTs with an operating voltage of 1.5V were fabracited at room temperature. These TFTs exhibit a good performance with a VTH of 0.32V, a large current on//off ratio of 1.2×10~6, a field-effect mobility of 13.5cm~2//Vs, and a low subthreshold swing of 130 mV//decade. In the fourth part, I prepared ITO TFTs with an operating voltage of 0.8V. The channel and source//drain electrode layers were deposited by one shadow mask, and the channel and source//drain electrode are prepared at the same time. In order to realize the low operating voltage, the SiO/_2 gate dielectric was immersed in 43.5/% LiCl aqueous solution, and a large number of ions enter the SiO/_2 gate dielectric. Owing to an enhanced electric double layer in t

关 键 词： 薄膜晶体管 低压 电容 双电荷层 介孔二氧化硅

领　　域： [电子电信]