Photopatternable ultrathin gate dielectrics for low-voltage-operating organic circuits

Abstract

We report here a photopatternable ultrathin gate dielectric for the fabrication of low-voltage-operating organic field-effect transistors (OFETs) and inverters. The gate dielectric material is composed of a photocrosslinkable polymer, poly(vinyl cinnamate), and a thermally crosslinkable silane crosslinking reagent, 1,6-bis(trichlorosilyl)hexane. The spin-coated dielectric is photocured with ultraviolet light, which enables fine film patterning via regular photolithography. After thermal curing (at 110 °C), the dielectric showed excellent insulating properties (a leakage current density of ≈10−7 A/cm2 at 2.0 MV/cm) for an ultrathin film thickness of 70 nm, thus reducing the operating voltage of the OFETs and inverters to −5 V.