High‐Performance Thin‐Film Transistors with Nickel‐Doped Indium Zinc Oxide Channel Layers

Abstract

High‐performance thin‐film transistors (TFTs) with amorphous nickel‐doped indium zinc oxide (a‐IZNO) channel layers are fabricated by radio‐frequency magnetron sputtering. The influence of nickel (Ni)‐doping content on the electrical properties of a‐IZNO TFTs are investigated. With increasing Ni‐doping content, the threshold voltage shifts to the positive direction, which is attributed to the reduction in oxygen vacancies. The a‐IZNO TFTs at Ni content of 6.6 at% exhibit optimum performance, with a field‐effect mobility of 30.2 cm2 V−1 s−1, a threshold voltage of −1.1 V, a subthreshold swing of 0.19 V decade−1, and an on‐to‐off current ratio of 3.7 × 107. In addition, the devices show high stability under positive and negative bias stress. These results suggest that Ni is an effective carrier suppressor for indium zinc oxide (IZO) thin film, making a‐IZNO a promising channel material for TFTs.