Temperature dependence and functionalization of solution processed high-k hybrid gate insulators for high performance oxide thin-film transistors

Abstract

We demonstrate a solution processed gate insulator (GI) with high dielectric constant (high-k) of up to ∼8.9 for high performance and low voltage operation amorphous InGaZnO (a-IGZO) thin-film transistors (TFTs). High mobilities of up to ∼30 cm2 V s−1, threshold voltage of <0.5 V, and low off current (∼10−12 A) can be achieved through the combination of high-k BaTiO x (BTO) nanoparticles and a polysiloxane (PSX) polymer matrix. This combination enables a lower process temperature of 300 °C from 650 °C while ensuring enhanced performance and low gate leakage current. We also show the tunability of the high-k hybrid BTO/PSX through fluorination and addition of a photosensitive property to further reduce the leakage current and inhibit dry etching related degradation. High-k hybrid BTO/PSX GI is a promising candidate for high performance and low-voltage operation oxide TFTs.