Chemical and Electrical Properties of Low-Temperature Solution-Processed In–Ga–Zn-O Thin-Film Transistors

Abstract—We have fabricated a bottom-gate thin-film tran-sistor (TFT) with the active layer of indium–gallium–zinc-oxide (IGZO) nanoparticles prepared from water solution. Polycrystal-lized InGaZn2O5 films were formed by a spin-coating method and postbaked at low temperature (95 ◦C). The morphology of the IGZO film indicates that not only are the grain size and shape uniform but also the cross section of the film appears dense, considering that the films were fabricated by a solution process at low temperature. The TFT device shows good switching ability, high drain current (> 105 A), and low threshold voltage (0.9 V). Its field-effect mobility of 2.3 cm2/V · s and ON–OFF current ratio over 106 are very promising for TFT applications. Index Terms—Indium–gallium–zinc oxide (IGZO), metal– insulator–oxide–semiconductor devices, solution-processed, thin-film transistors (TFTs)