Indium–Tin–Oxide Thin-Film Transistors With In Situ Anodized Ta₂O₅Passivation Layer

Abstract

An in situ passivation process for the fabrication of high-performance indium-tin-oxide thin-film transistors (ITO TFTs) is demonstrated, in which a localized anodic oxidization (anodization) technique is used to convert the metal Ta film on a channel layer into a Ta ₂ O ₅ film to form a channel passivation layer. At the same time, the high conductive ITO layer is modulated into an appropriate active layer due to filling of oxygen vacancies during the anodization. The fabricated ITO TFT shows a high mobility of 56.1 cm ² /Vs, a proper threshold voltage of 1.7 V, a steep subthreshold slope of 0.14 V/decade, and a high ON/OFF current ratio exceeding 10 ⁹ . A good electrical stability under gate-bias stress is also observed with the ITO TFTs.