Rapid thermal annealing effect on performance variations of solution processed indium–gallium–zinc-oxide thin-film transistors

In this paper, the 1 min annealing effect on the electrical characteristics of solution-processed amorphous indium–gallium–zinc-oxide thin-film transistors (a-IGZO TFTs) was analyzed in an ambient gas environment comprising He, Ar, N2, and O2 and an annealing temperature range from 400 to 600 °C for different active layer thicknesses. Even for the short annealing time of 1 min, the He-annealed TFTs show good performance with a threshold voltage of −1.27 V, a subthreshold slope of 605 mV/dec, and a field-effect mobility of 7.19 cm2/Vs under the thick active layer condition. The resulting good performance of the He-annealed TFT originates from the high thermal velocity of the He atom, which can be confirmed from the x-ray photoelectron spectroscopic measurement by the sharp definition of the active layer near the a-IGZO/gate insulator interface.