Postannealing Process for Low Temperature Processed Sol-Gel Zinc Tin Oxide Thin Film Transistors

Abstract

We fabricated zinc tin oxide (ZTO) thin film transistors (TFTs) using a stable ZTO sol-gel solution at a low annealing temperature of 300 degrees C. To enhance transistor performance, the ZTO films were postannealed under vacuum and wet air consecutively. The vacuum and wet air postannealed ZTO TFTs exhibited high saturation mobilities (5.5 cm(2)/V s), low subthreshold swing (0.38 V/dec), and high on-off current ratio (8x10(8)). We analyzed the ZTO films before and after postannealing by X-ray photoelectron spectroscopy to explain the origin of the enhanced performance.