Hydrogenated In–Ga–Zn–O thin-film transistors with anodized and fluorinated Al 2 O 3 gate insulator for flexible devices

For the purpose of developing In–Ga–Zn–O (IGZO) thin-film transistors (TFTs) on a flexible substrate, low-temperature (150 °C) processed hydrogenated IGZO (IGZO:H) TFTs with anodize alumina gate insulator (Al 2 O 3 GI) have been developed. We found that fluorination of the Al 2 O 3 GI surface significantly improves field effect mobility ( μ FE ) and positive gate bias and temperature stress (PBTS) reliability of the TFTs. μ FE of 28.8 cm 2 V −1 s −1 and good PBTS reliability were obtained from the IGZO:H TFTs with a 68 nm thick fluorinated Al 2 O 3 GI. X-ray photoelectron spectroscopy analysis revealed that fluorine in the AlOF x formed at the Al 2 O 3 surface played an important role in improving performance and PBTS reliability of low-temperature-processed oxide TFTs for future flexible device applications.