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

High-performance amorphous indium-gallium-zinc oxide thin-film transistors (IGZO TFTs) were demonstrated at 360°C with the IGZO channel and aluminium oxide (AlOx) gate dielectric stack that was deposited by ozone (O3)-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 O3oxidant 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 7.5 cm2/ Vs and 0.38 V/dec, respectively, by the O3oxidant introduced in the IGZO and AlOx depositions. The O3oxidant is very effective in improving the electrical properties of solution-processed oxide TFTs.