A water-borne photo-sensitive polyimide precursor for an eco-friendly process of preparing organic thin film transistors

Abstract

Water-based synthesis of a polymeric precursor for polyimides is an eco-friendly and energy- and cost-effective approach to producing high-performance engineering plastics. Although a combination of monomers and organic bases has been suggested, the introduction of a photocrosslinkable functionality remains a challenging task in the fabrication of sophisticated microelectronic devices. In this study, we developed a water-based synthesis of a photo-patternable polymeric precursor for polyimides by adopting acrylamide with a tertiary amine moiety. Our strategy provides a one-pot synthesis of the aromatic polyimide precursor in water. The formulation with a dithiol crosslinker further offers selective photocrosslinking under UV irradiation via a thiol–ene click reaction. The patterned polymer was successfully converted into micropatterned polyimides with various morphologies, including dot and line patterns. By applying our photolithography process to the fabrication of microelectronic devices, an organic thin-film transistor with a patterned dielectric layer was successfully prepared. This study opens up an eco-friendly process for advanced microelectronic devices by providing a synthetic strategy for water-based photocrosslinkable polyimide precursors.