未退火InGaZnO作为缓冲层的InGaZnO薄膜晶体管性能研究

Effects of using InGaZnO without annealing as buffer layer on the performance of InGaZnO thin film transistors

铟镓锌氧化物薄膜晶体管(IGZO TFT)因具有场效应迁移率高,大面积均匀性好,无定型态等特点,被认为是显示器朝着大尺寸、柔性化方向发展的新型背板技术。源漏电极与有源层之间的接触氧化会增大器件的接触电阻,从而导致器件的性能降低。利用未退火IGZO具有氧含量低、氧空位多、电导率高的特点,提出采用未退火IGZO作为源漏电极缓冲层,以减少源漏电极与有源层之间的接触氧化。研究发现插入4nm未退火IGZO缓冲层时,相对于未采用缓冲层的器件,其饱和区场效应迁移率提高了11.6%,阈值电压降低了3.8V,器件性能有所提高。此外,该方法还可以在原位退火之后继续使用与有源层相同的材料溅射生长缓冲层,能够使得在采用矩形靶溅射方式的工业生产中,制备缓冲层工艺更加简单。

Due to the characters of high field effect mobility,good uniformity on large area and amorphous,indium-gallium-zinc-oxide thin film transistors is considered to be a new drive technology for the displays with large size and flexible character.However,the metal contact oxidation between source/drain electrode and active layer will increase the contact resistance and cause performance degradation.IGZO film without annealing has the characters of low oxygen content,more oxygen vacancies and high electrical conductivity.This article proposed using IGZO film without annealing as drain/source electrode buffer layer to reduce the contact oxidation and reduce the contact resistance.Experimental results indicated that the best performance of device can be obtained,when inserting 4nm IGZO buffer layer,the mobility improved by 11.6% and the threshold voltage reduced 3.8Vcompared with the device without buffer layer.In conclusion,the buffer layer can effectively improve the per-formance of device.In addition,using the same material with active layer as buffer layer can simplify the process compared with other material as buffer layer in industrial production with single rectangular target.