制备工艺对非晶铟锡锌氧化物薄膜晶体管的性能影响研究

发布时间：2018-03-22 06:35

本文选题：非晶氧化物薄膜晶体管(AOS-TFTs)　切入点：非晶铟锡锌氧化物(a-ITZO)　出处：《中北大学》2015年硕士论文　论文类型：学位论文

【摘要】：基于柔性基片的薄膜晶体管(TFTs)是实现柔性电子器件的关键组成部分，由于其在开发先进光电器件方面的重大作用而成为未来不可或缺的网络技术。近年来，由于非晶氧化物半导体(AOS)具有较宽光禁带(3.5eV)、良好的导电性(103Ωcm-1)和较高的光透率(80%)等优势而广泛应用于薄膜晶体管(TFTs)中,大有替代传统Si系列TFTs的趋势，，成为下一代平板显示器的前景材料。尤其以非晶铟锡锌氧化物(a-ITZO)为有源层的TFTs更是吸引了人们众多的注意力。目前，溅射是TFTs器件的主要制备方式，改变制备工艺参数可以有效改善器件的性能。本论文就TFTs器件制备工艺的改变对器件电气性能及稳定性的影响展开研究，主要对影响TFTs器件性能优化的器件结构、有源层组成成分、源/漏电极之间接触电阻和栅介质材料等因素进行了详细且系统地研究及分析，提出了造成器件不稳定性的因素以及调整制备工艺条件对器件性能影响的理论依据；并以硅作为衬底，采用不同直流(DC)磁控溅射功率和Ar/O2流量比制备了基于a-ITZO有源层的TFTs器件。经过对器件进行电气性能及稳定性的测试，结果表明不同溅射功率和氧气含量主要通过改变沟道层和绝缘层接触面之间陷阱密度(Nt)以及沟道内载流子浓度(Nd)等因素，进而对TFTs器件的性能产生影响：i)采用不同溅射功率制备的器件，在80W下显示出优秀的电气性能：0.16V/dec的亚阈值摆幅(S.S)、-3.60V的开启电压(VON)、-1.87V的阈值电压(VTH)和高达7.77×108的电流开关比(ION/IOFF)。与此同时，在负向偏置压力下，该器件也显示出最强的电气稳定性。ii)采用不同氧含量制备的器件，在氧含量为30%时显示出最优质的电气性能：最小的S.S=0.18V/dec、最低的开启电压VON=-3.00V和阈值电压VTH=-2.35V以及高达1.15×109的ION/IOFF和43.88cm2V-1s-1的μFE。通过实验验证了制备工艺变更对优化a-ITZO TFTs性能的可行性，进而为今后得出合理的制备条件提供依据，以使器件获得更优的性能。
[Abstract]:TFTs (thin Film Transistor based on flexible substrate) is a key component of realizing flexible electronic devices. Due to its important role in the development of advanced optoelectronic devices, TFTs become an indispensable network technology in the future. The amorphous oxide semiconductor (AOS) is widely used in thin film transistors (TFTs) because of its advantages of wide optical band gap (3.5eV), good electrical conductivity (103惟 cm-1) and high optical transmittance (TFTs), and has a tendency to replace traditional Si series TFTs. TFTs with amorphous indium tin zinc oxide (ITZO) as the active layer has attracted much attention. Currently, sputtering is the main way to fabricate TFTs devices. The performance of the device can be improved by changing the process parameters. In this paper, the effects of the fabrication process of TFTs on the electrical properties and stability of TFTs devices are studied, including the components of the active layer and the structure of the devices that affect the performance optimization of TFTs devices. The contact resistance between source and leakage electrode and gate dielectric material are studied and analyzed in detail. The factors that cause the instability of the device and the theoretical basis of adjusting the preparation conditions on the performance of the device are put forward. Using silicon as substrate, TFTs devices based on a-ITZO active layer were fabricated by using different DC DC magnetron sputtering power and Ar/O2 flux ratio. The electrical properties and stability of the devices were tested. The results show that the different sputtering power and oxygen content are mainly by changing the trap density between the channel layer and the insulating layer contact surface and the carrier concentration in the channel. Furthermore, the performance of TFTs devices is affected by using different sputtering power. The device with different sputtering power shows excellent electrical performance at 80W: 0.16V / dec sub-threshold swinging voltage, the threshold voltage (VTHs) and the current switching ratio up to 7.77 脳 10 ~ 8V ~ (-1.87) V ~ (-1.87) V ~ (-1.87) V ~ (-1.87) V ~ (?) ~ (?) ~ (?) ~ (?) ~ (?) and the current / switching ratio up to 7.77 脳 10 ~ 8 ~ (8). At the same time, at the same time, Under negative bias pressure, the device also shows the strongest electrical stability. Ii) made of different oxygen content, At the oxygen content of 30, the best electrical properties were shown: the smallest S.S 0.18V / R, the lowest open voltage VON=-3.00V and threshold voltage VTH=-2.35V, and the ION/IOFF as high as 1.15 脳 10 ~ 9 and the 渭 FE of 43.88cm2V-1s-1. The feasibility of the preparation process modification to optimize the performance of a-ITZO TFTs was verified by experiments. It provides the basis for obtaining reasonable preparation conditions in the future, so that the device can obtain better performance.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN321.5

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