High Performance All Oxide Thin Film Transistor With Ink-Jet Printing Metal Oxide Dielectric Pattern

Abstract

In this paper, the effect of the printing parameters on the forming behavior of dot, line and plane for hafnium aluminum oxide (HAO) is thorough investigated by simulation and experiment. At first, the spreading process of inkjet droplets has been numerically simulated through the utilization of the volume of fluid (VOF) model. And the optimal contact angle and drop space for printing HAO pattern were obtained. Ultrasonic treatment can remove some polar hydrophilic molecules on the surface of the substrate, which controlled the spread of the printed patterns. The inkjet-print HAO film exhibits the permittivity of 9.3 at 100kHz and afforded a leakage current below 10-6 A/cm2 at 2 MV. Finally, the fabricated TFTs using inkjet print exhibit mobility (μ) of 8.89 cm2v-1s-1, subthreshold swing (SS) of 0.09 V/decade and ON-OFF-current ratio (Ion/Ioff) of 8.69×108. Implied that the ultrasonic treatment can serve as guidelines for high quality printing pattern.

Keywords: Inkjet print, surface free energy, Morphology, simulation, thin-film transistors