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

Abstract

This letter demonstrates the feasibility of full room temperature InGaZnO thin-film transistor (TFT) using trilayer gate dielectric on flexible substrate. Through integrating high- <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\kappa~{\rm SiO}_{2}/{\rm TiO}_{2}/{\rm SiO}_{2}$</tex></formula> (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 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">${\rm cm}^{2}/{\rm Vs}$</tex> </formula> , and good <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$I_{{\rm ON}}/I_{{\rm OFF}}$</tex></formula> ratio of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$6.7\times 10^{5}$</tex></formula> , which have the potential for the application of high-resolution flexible display.