High-Performance Solution-Processed InGaZnO Thin-Film Transistor Fabricated by Ozone-Assisted Atmospheric Pressure Mist Deposition

Abstract

High-performance amorphous indium-gallium–zinc oxide thin-film transistors (IGZO TFTs) were demonstrated at ${\hbox{360}} ^{\circ}{\hbox{C}}$ with the IGZO channel and aluminium oxide (AlOx) gate dielectric stack that was deposited by ozone $({\hbox{O}}_{3})$ -assisted atmospheric pressure chemical vapor deposition (AP-CVD) using an ultrasonic atomized solution mist. The AlOx gate dielectric with a breakdown electric field of over 8 MV/cm and dielectric constant of 7.0 was obtained. In addition, the introduction of ${\hbox{O}}_{3}$ oxidant during the IGZO deposition decreases the carbon and hydrogen contamination in the film. Field effect mobility and the sub-threshold swing of the IGZO TFT with AP-deposited IGZO/AlOx stack were significantly improved to ${\hbox{7.5}}~{\hbox{cm}}^{2} / {\hbox{V}}{\hbox{s}}$ and 0.38 V/dec, respectively, by the ${\hbox{O}}_{3}$ oxidant introduced in the IGZO and AlOx depositions. The ${\hbox{O}}_{3}$ oxidant is very effective in improving the electrical properties of solution-processed oxide TFTs.