Preparation and effects of post-annealing temperature on the electrical characteristics of Li-N co-doped ZnSnO thin film transistors

In this study, transparent Li-N co-doped ZnSnO (ZTO: (Li, N)) thin film transistors (TFTs) with a staggered bottom-gate structure were fabricated by radio frequency magnetron sputtering at room temperature. Emphasis was placed on investigating the effects of post-annealing temperature on their physical and electrical properties. An appropriate post-annealing temperature contributes not only to achieving good quality thin films, but also to improving the electrical performance of the ZTO: (Li, N) TFTs. The ZTO: (Li, N) TFTs annealed at 675 °C showed the best electrical characteristics with a high saturation mobility of 26.8 cm2V−1s−1, a threshold voltage of 6.0 V and a large on/off current ratio of 4.5×107.