Resumen
The indium-free amorphous oxide semiconductor thin film transistor (AOS-TFT) with aluminum (Al) electrodes shows broad application prospects in new-generation display technologies, such as ultra-high definition large-screen display, OLED display and 3D display. In this work, the thin film transistor (TFT) with a zinc-aluminum-tin-oxide (ZATO) semiconductor as the active layer and an Al electrodes as the source and drain (S/D) was investigated. The optical, electrical and semiconductive properties of the ZATO films were evaluated by atomic force microscopy (AFM), ultraviolet?visible spectrophotometry and microwave photoconductivity decay (µ-PCD), respectively. The result shows that the film is smooth and transparent and has low localized states and defects at a moderate oxygen concentration (~5%) and a low sputtering gas pressure (~3 mTorr). After the analysis of the transfer and output characteristics, it can be concluded that the device exhibits an optimal performance at the 623 K annealing temperature with an Ion/Ioff ratio of 5.5 × 107, an SS value of 0.15 V/decade and a saturation mobility (µsat) of 3.73 cm2·V-1·s-1. The ZATO TFT at the 623 K annealing has a -8.01 V negative shift under the -20 V NBS and a 2.66 V positive shift under the 20 V PBS.