Water-Borne Fluorinated Polyimide Dielectric for Large-Area IGZO Transistors and Logic Gates

Abstract

Thin-film transistors offer excellent and uniform electrical properties over large areas, making them a promising option for various future electronic devices. Polyimide dielectrics are already widely used in various electronic devices because of their exceptional dielectric properties, thermal stability, and desirable mechanical flexibility, which make them suitable for harsh environments. However, the current research on polyimide dielectric materials has certain limitations, such as the use of toxic solvents, high-temperature processes, and deficient coating properties. Herein, we introduce an aromatic polyimide dielectric, which exhibits excellent electrical properties even when processed at a low temperature of 250 degrees C using environmentally friendly water-based "one-step" polymerization. Despite its thin thickness of <200 nm, the water-borne fluorinated polyimide dielectric material demonstrates stable insulating properties over a wide range of electric fields and achieves a high breakdown voltage of over 4.5 MV cm-1. Furthermore, we successfully achieved a large-area coating of uniform dielectric layers with no pinholes using only water as a solvent and a simple solution process without any additional processing steps. These results demonstrate that the water-borne polyimide gated indium-gallium-zinc oxide transistor exhibits excellent and stable device performance. Moreover, we used the transistor to successfully demonstrate various logic gates (NOT, NAND, and NOR). Overall, this study provides guidelines for the eco-friendly and sustainable use of water-borne polyimide dielectric materials with high electrical performance and large-processing window advantages.