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

摘要

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 cm(2) 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 x 10(7). 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.