摘要
在室温下,采用射频磁控溅射法制备了氧化铟锡锌(ITZO)薄膜作为薄膜晶体管(TFT)的有源层, ITZO薄膜厚度分别为16, 25, 36, 45和55 nm。采用X射线衍射仪(XRD)、扫描电镜(SEM)和紫外-可见光分光光度计测试分析了不同厚度ITZO薄膜的结晶情况、表面形貌及光学特性的变化规律,并使用半导体特征测试仪表征了ITZO TFT的输出特性及转移特性,研究了有源层厚度对ITZO TFT电学性能的影响。结果表明:不同厚度的ITZO薄膜均为非晶结构,成膜致密,薄膜在可见光范围内的平均透过率均高于85%。在界面态密度(N■)和载流子浓度的共同影响下,当有源层厚度为36 nm时, ITZO TFT电学性能最优。其场效应迁移率(μ_(FE))为14.04 cm^2·(V·s)^(-1),开关比(I_(on/off))为1×10~6,亚阈值摆幅(S)仅有0.5 V·dec^(-1)。此外,有源层厚度的增大可以削弱空气中水分和氧气对TFT的侵蚀,提高器件的稳定性。因此可以通过改变有源层厚度来调控TFT的性能。
InSnZnO thin film transistors(ITZO TFT) were prepared by radio frequency(RF) magnetron sputtering at room temperature. The thickness of ITZO films was 16, 25, 36, 45 and 55 nm. Their crystallinity, morphology and optical characteristics were investigated by X-ray diffraction(XRD), scanning electron microscope(SEM) and ultraviolet-visible(UV-Vis) spectrophotometer. Meanwhile, the output characteristics and transfer characteristics of TFT were analyzed by semiconductor characterization system. The influence of the active layer thickness on the electrical performance of ITZO TFT was studied. The results showed that the ITZO films with different thickness were amorphous and compact;the average transmittance was over 85% for all the films. Under the combined effect of interface state density and carrier concentration, ITZO TFT exhibited optimal electrical characteristics when the ITZO active layer thickness was 36 nm. Its field-effect mobility(μFE), on/off radio(Ion/off) and sub-threshold swing(S) were 14.04 cm2·(V·s)-1, 1×106 and 0.5 V·dec-1, respectively. Additionally, increasing the active layer thickness could weaken the erosion on the TFT by water and oxygen, then further enhance the device′s stability. Thus, the performance of TFT could be controlled by varying active layer thickness.
作者
杨浩志
李治玥
刘媛媛
孙珲
吕英波
刘超
Yang Haozhi;Li Zhiyue;Liu Yuanyuan;Sun Hui;LüYingbo;Liu Chao(Supercomputing Center,Shandong University,Weihai 264209,China;School of Space Science and Physics,Shandong University,Weihai 264209,China;School of Business,Shandong University,Weihai 264209,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2019年第1期61-66,共6页
Chinese Journal of Rare Metals
基金
山东省自然科学基金项目(ZR2018QEM002)
山东大学(威海)青年学者未来计划资助
关键词
射频磁控溅射
ITZO薄膜
薄膜晶体管
厚度
RF magnetron sputtering
InSnZnO(ITZO) thin films
thin film transistors(TFTs)
thickness
