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.