高性能金属铟镓锌氧化物TFT的研究

Improvement of Indium Gallium Zinc Oxide Thin Film Transistor with Etch-Stop Layer of Bottom-Gate

在2.5 G试验线上研究了金属氧化物IGZO薄膜晶体管(TFT)的性能,获得良好的IGZO TFT性能,迁移率为10.65cm2/V·s,阈值电压Vth为-1.5 V,开态电流为1.58×10-4 A,关态电流为3.0×10-12,开关比为5.27×107,亚阈值摆幅为0.44V/Dev,验证了TFT的均一性和重复性。此外还研究了可见光照和电压偏应力对IGZO TFT性能的影响,可见光照不会促使IGZO TFT Vth的漂移,进行2 h的负偏电压应力测试,IGZO TFT的Vth几乎没有漂移。使用上述IGZO TFT基板成功地制作了中国大陆第一款Oxide-LCD样机(18.5英寸),展现出良好的效果。

A novel technique was developed to avoid etching of the indium gallium zinc oxide （IGZO） films by H3P04 or H20z in fabricating the thin film transistor （TFT）. The newly-developed technique involved an etch-stop layer of the bottom-gate. The characteristics of the prototyped IGZO- TFT ,fabricated with the etch-stop layer on the 2. 5 G trial production line, were experimentally evaluated. In addition to good uniformity and high reliability, the measured results included： a mobility of 10.65 cm^2 IV· s, a threshold voltage of - 1. 5 V, an on-state current of 1. 58 × 10^ - 4 A, an off-state current of 3 .0 × 10 ^- 12 A, a switching ratio of 5.27 × 10^ -7, and a sub-threshold swing of 0. 44/Dev . Besides, the irradiation of visible lights and voltage bias stress were found to have little impact on the IGZO- TFT performance. The first 18.5 inch, oxide- LCD （liquid crystal display） was successfully made with the IGZO- TFT .