High Stability InGaZnO4 Thin-Film Transistors Using Sputter-Deposited PMMA Gate Insulators and PMMA Passivation Layers

Abstract

We report on the fabrication and characterization of sputter-deposited poly(methyl methacrylate) (PMMA) thin films used as gate insulators as well as passivation layers in high performance InGaZnO4 thin-film transistors (TFTs). Sputter-deposited PMMA thin films exhibited a dielectric constant of 4.3 and low leakage current characteristics (<similar to 2x10(-8) A/cm(2) at 0.3 MV/cm). The InGaZnO4 TFTs utilizing PMMA gate insulators and PMMA passivation layers exhibited a high on/off current ratio of 4.08x10(6) and a high field-effect mobility of 36.1 cm(2)/V s. Threshold voltage and field-effect mobility remained constant after aging in air atmosphere for 5 months.