Low-temperature formation of high-mobility a-lnGaZnOx films using plasma- enhanced reactive processes

摘要

This work demonstrated the low-temperature fabrication of high-mobility a-InGaZnOx (a-IGZO) films using plasma-enhanced reactive processing. The effect of the post-processing temperature on the performance of IGZO thin-film transistors (TFTs) using these a-IGZO films as a channel layer was also investigated. IGZO TFTs incorporating a-IGZO films plasma-treated at temperatures as low as 200 degrees C exhibited the expected TFT transfer characteristics, with field effect mobility values as high as 40 cm(2) V-1 s(-1). The fabrication of IGZO TFTs that exhibited homogeneous characteristics over large substrate areas was attempted, by assessing the effects of the plasma treatment on a-IGZO films deposited at various oxygen flow rate ratios. The electrical properties of IGZO TFTs using plasma-treated films were found to be dramatically improved, irrespective of the film deposition conditions prior to the plasma treatment. These results confirm the feasibility of producing IGZO TFTs with uniform characteristics over large substrates areas. (C) 2019 The Japan Society of Applied Physics