射频磁控溅射低温制备非晶铟镓锌氧薄膜晶体管

Fabrication of Amorphous Indium Gallium Zinc Oxide Thin Film Transistor at Low Temperature by RF Magnetron Sputtering

利用射频磁控溅射技术室温制备了铟镓锌氧(IGZO)薄膜,采用X射线衍射(XRD)表征薄膜的晶体结构,原子力显微镜(AFM)观察其表面形貌,分光光度计测量其透光率。结果表明:室温制备的IGZO薄膜为非晶态且薄膜表面均匀平整,可见光透射率大于80%。将室温制备的IGZO薄膜作为有源层,在低温(<200℃)条件下成功地制备了铟镓锌氧薄膜晶体管(a-IGZO TFT),获得的a-IGZO-TFT器件的场效应迁移率大于6.0 cm2.V-1.s-1,开关比约为107,阈值电压为1.2 V,亚阈值摆幅(S)约为0.9 V/dec,偏压应力测试a-IGZO TFT阈值电压随时间向右漂移。

The indium gallium zinc oxide（IGZO） thin films were fabricated by RF magnetron sputtering at room temperature in this paper.The crystal structure,surface morphology,and optical electrical of the IGZO films were investigated by X-ray diffraction（XRD）,atom force microscopy（AFM）,and photometry,respectively.The results revealed that the IGZO film was amorphous,the surface of the films was uniform and smooth.A good optical transmittance of over 80% was obtained in the visible light.The IGZO thin film transistors were successfully fabricated at low temperature（200 ℃） using the room temperature sputtering IGZO thin film as the active layer.The field effect mobility of a-IGZO TFT was larger than 6.0 cm2·V-1·s-1.The device＇s on/off ratio was 107,threshold voltage was 1.2 V and subthreshold voltage swing is 0.9 V/ dec.Constant bias stress testing showed that the a-IGZO TFT threshold voltage exhibited positive shifts as time increased.