非晶铟镓锌氧化物薄膜晶体管的制备及其光敏特性研究

Fabrication and Photosensitive Properties of Amorphous Indium Gallium Zinc Oxide Thin Film Transistors

基于射频磁控溅射法制备了以非晶铟镓锌氧化物(a-IGZO)作为有源层的底栅顶接触式薄膜场效应晶体管(Thin Film Transistor,TFT),其长/宽比为300μm/100μm。研究了该器件在无激光和在三种不同波长激光照射下的光敏特性。实验表明,器件在波长分别为660、450和405nm三种激光照射下的阈值电压Vth分别为4.2、2.5和0V,均低于无激光时的4.3V,且器件的阈值电压随激光波长减小单调降低,此外,随着激光波长的下降,'明/暗'电流比K由0.54上升到8.06(在VGS=6V且VDS=5V条件下),光敏响应度R由0.33μA/mW上升到4.88μA/mW,可见激光波长越短,可获得更强的光电效应,光灵敏度也更高,该效应表明该器件在光电探测等领域具有广阔的应用前景。

Amorphous indium-gallium-zinc-oxide(a-IGZO)with a length of 300μm and a width of 100μm was fabricated by RF magnetron sputtering.A thin film transistor(TFT)with a structure of Si(P)/La2O3/a-IGZO/TC(20 nm Ti,80 nm Au)was fabricated.The optoelectronic characteristics of the device were studied by probe method without laser irradiation and with laser irradiation of three different wavelengths.The experimental results show that the threshold voltage(Vth)of the device irradiated by 660,450 and 405 nm lasers is 4.2,2.5 and 0 V,respectively,lower than the Vthwithout laser,the smaller the wavelength is,the lower Vthis.With the decrease of wavelength,its current ratio(K)of photocurrent to current in dark increases from 0.54 to 8.06,and the responsivity(R)increases from 0.33μA/mW to4.88μA/mW when VGS=6 Vand VDS=5 V.It shows that the photoelectric effect is stronger and the optical sensitivity is higher with the smaller wavelength of the visible laser.This effect indicates that the device has broad application prospects in the field of photoelectric detection.