Self-patterning methodology by spin coating for oxide thin-film transistors

Abstract

This paper reports a novel method for patterning an active layer by simple taping and spin coating without lithography equipment for solution-processed oxide thin-film transistors (TFTs) fabrication. A solution-processed self-patterned thin film could be prepared on the non-taped area by pushing the solution out from the taped area because the surface properties of SiO2 had been changed from hydrophilic to hydrophobic through the application of a polyimide (PI) tape. The electrical properties of the self-patterned ZTO TFTs proved better than those of the spin-coated TFTs, showing a saturation mobility of 2.64 cm2/V s, a threshold voltage of 0 V, an on-to-off current ratio of 1.55 × 107, and a subthreshold slope of 0.5 V/dec after 400 °C annealing with improved contact characteristics and bias stress stability.