title: Water-Mediated Photochemical Treatments for Low-Temperature Passivation of Metal-Oxide Thin-Film Transistors.
abstract: The low-temperature electrical passivation of an amorphous oxide semiconductor (AOS) thin-film transistor (TFT) is achieved by a deep ultraviolet (DUV) light irradiation-water treatment-DUV irradiation (DWD) method. The water treatment of the first DUV-annealed amorphous indium-gallium-zinc-oxide (a-IGZO) thin film is likely to induce the preferred adsorption of water molecules at the oxygen vacancies and leads to subsequent hydroxide formation in the bulk a-IGZO films. Although the water treatment initially degraded the electrical performance of the a-IGZO TFTs, the second DUV irradiation on the water-treated devices may enable a more complete metal-oxygen-metal lattice formation while maintaining low oxygen vacancies in the oxide films. Overall, the stable and dense metal-oxygen-metal (M-O-M) network formation could be easily achieved at low temperatures (below 150 °C). The successful passivation of structural imperfections in the a-IGZO TFTs, such as hydroxyl group (OH-) and oxygen vacancies, mainly results in the enhanced electrical performances of the DWD-processed a-IGZO TFTs (on/off current ratio of 8.65 × 10(9), subthreshold slope of 0.16 V/decade, an average mobility of >6.94 cm(2) V(-1) s(-1), and a bias stability of ΔVTH < 2.5 V), which show more than a 30% improvement over the simple DUV-treated a-IGZO TFTs.
authors.affiliation: School of Electrical and Electronics Engineering, Chung-Ang University , Seoul 156-756, Korea.
authors.forename: Jae Sang
authors.initials: JS
authors.lastname: Heo
authors.affiliation: School of Electrical and Electronics Engineering, Chung-Ang University , Seoul 156-756, Korea.
authors.forename: Jeong-Wan
authors.initials: JW
authors.lastname: Jo
authors.affiliation: School of Electrical and Electronics Engineering, Chung-Ang University , Seoul 156-756, Korea.
authors.forename: Jingu
authors.initials: J
authors.lastname: Kang
authors.affiliation: School of Electrical and Electronics Engineering, Chung-Ang University , Seoul 156-756, Korea.
authors.forename: Chan-Yong
authors.initials: CY
authors.lastname: Jeong
authors.affiliation: UNIST Central Research Facilities, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, Korea.
authors.forename: Hu Young
authors.initials: HY
authors.lastname: Jeong
authors.affiliation: Department of Materials Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea.
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Kim
authors.affiliation: Department of Physics, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 689-798, Korea.
authors.forename: Kwanpyo
authors.initials: K
authors.lastname: Kim
authors.affiliation: School of Electrical and Electronics Engineering, Chung-Ang University , Seoul 156-756, Korea.
authors.forename: Hyuck-In
authors.initials: HI
authors.lastname: Kwon
authors.affiliation: School of Advanced Materials Science and Engineering, Hanbat University , Daejeon 305-719, Korea.
authors.forename: Jaekyun
authors.initials: J
authors.lastname: Kim
authors.affiliation: School of Advanced Materials Science and Engineering, Sungkyunkwan University , Suwon, Korea.
authors.forename: Yong-Hoon
authors.initials: YH
authors.lastname: Kim
authors.affiliation: Department of Chemistry, Chung-Ang University , Seoul, Korea.
authors.forename: Myung-Gil
authors.initials: MG
authors.lastname: Kim
authors.affiliation: School of Electrical and Electronics Engineering, Chung-Ang University , Seoul 156-756, Korea.
authors.forename: Sung Kyu
authors.initials: SK
authors.lastname: Park
keywords: DUV irradiation; low temperature; solution-processed metal oxides; thin-film transistors; water treatment