Solution-processed yttrium oxide dielectric for high-performance IZO thin-film transistors

In this paper, we report the annealing effects on the micro-structure and the electrical properties of sol–gel-derived Y2O3 thin films and further impact on the InZnO thin film transistors (IZO TFTs). The Y2O3 thin films annealed at 400 °C showed a low current density of ~10−8 A/cm2 at an applied voltage of 1 V. A relative high capacitance density of 345.7 nF/cm2, measured at 1 kHz, was obtained for same Y2O3 capacitor. Based on its potential as the dielectric layer, IZO TFTs exhibited a high field effect mobility of 20.93 cm2/Vs, an acceptable subthreshold swing of 0.67 V/decade, and a reasonable Ion/Ioff ratio of 1.2×106. Our results demonstrate that solution-processed Y2O3 thin film is a promising gate dielectric candidate for high-performance oxide TFT.