A Flexible IGZO Thin-Film Transistor With Stacked ${\rm TiO}_{2}$ -Based Dielectrics Fabricated at Room Temperature

This letter demonstrates the feasibility of full room temperature InGaZnO thin-film transistor (TFT) using trilayer gate dielectric on flexible substrate. Through integrating high- $\kappa ~{\rm SiO}_{2}/{\rm TiO}_{2}/{\rm SiO}_{2}$ (STS) gate-stack as well as InGaZnO channel thickness modulation, the resulting flexible indium–gallium–zinc oxide (IGZO)/STS TFTs show low threshold voltage of 0.5 V, small subthreshold swing of 0.129 V/decade, high field effect mobility of 76 ${\rm cm}^{2}/{\rm Vs}$ , and good $I_{{\rm ON}}/I_{{\rm OFF}}$ ratio of $6.7\times 10^{5}$ , which have the potential for the application of high-resolution flexible display.