Effect of secondary atmosphere annealing on electrical properties of a-IGZO thin film transistor

Amorphous indium gallium zinc oxide thin film transistors (a-IGZO TFTs) were fabricated and annealed under different environment. Compared to devices annealed at one time, the secondary annealing devices show better electrical properties and have a smaller subthreshold swing (~1.43 V/decade) and better magnetic viscosity stability. By comparing the performance and technology of the devices with different annealing treatments, it is found these significant improvements are duo to the additional relatively short second annealing (about 30 min) after the first annealing treatment. This illustrates that a-IGZO films with smooth surface and dense structure can be obtained by introducing the second annealing treatment to a-IGZO TFT.