氧气等离子体处理提升InZnO材料及TFT电学性能和稳定性研究

Improvement of the Electrical Performance and Stability of InZnO Material and TFT by Oxygen Plasma Processing

氧化物薄膜晶体管(TFT)是有源矩阵有机发光二极管的核心驱动元件,是现今开发新型显示器的关键技术,在平板显示方面具有广阔的应用前景。但氧化物半导体中存在大量由氧空位引起的缺陷态,从而影响了TFT器件的性能及稳定性,成为其商业化进程的瓶颈。本文通过磁控溅射方法制备了IZO TFT,并将其进行O2等离子体处理,研究了离子体处理对IZO薄膜及TFT性能的影响。结果表明:O2等离子体处理后IZO TFT迁移率由8.2cm^(2)/(V·s)提高到9.5cm^(2)/(V·s),阈值电压由-3.2V减小到-5.1V,亚阈值摆幅由0.45V/decade减小到0.38V/decade,开关比由2.3×10^(7)提高到4.4×10^(7);在光照负偏压下,器件的阈值电压漂移量从7.1V降低到3.2V;在100℃老化条件下,器件的阈值电压漂移量从12.5V降低到6.4V;O2等离子体处理可以有效提高IZO TFT的电学性能和稳定性。

Oxide thin film transistors(TFT)are the core driving components of active matrix organic light-emitting diodes,and are the key technology for developing new displays today.They have broad application prospects in flat panel displays.However,there are a large number of defect states in oxide semiconductors caused by oxygen vacancies,which destroy the performance and stability of TFT device,and become a bottleneck technical problem for its commercialization.Therefore,IZO TFT was prepared by RF-sputtering and treated with O2 plasma to study the effects of O2 plasma treatmert on IZO film and device performance and stability.The results show that after plasma treatment,the mobility of IZO TFT increases from 8.2cm^(2)/(V·s)to 9.5cm^(2)/(V·s),the threshold voltage changes from-3.2V to-5.1V,the sub-threshold swing decreases from 0.45V/decade to 0.38V/decade,and the switch ratio changes from 2.3×10^(7)to 4.4×10^(7).Under negative light bias,the threshold voltage drift of the device reduces from 7.1V to 3.2V.The threshold voltage drift of the device decreases from 12.5V to 6.4V when aging at 100℃.O2 plasma treatment can effectively improve the electrical performance and stability of IZO TFT.