Influence of Weight Ratio of Poly(4-vinylphenol) Insulator on Electronic Properties of InGaZnO Thin-Film Transistor

Abstract

Spin-coated organic PVP layers were used as dielectric layers in a-IGZO TFTs. Weight ratios of 20 : 1, 10 : 1, and 5 : 1 for PVP and PMF, a cross-linking agent, were used. The a-IGZO TFTs with the PVP : PMF ratio of 20 : 1 showed a large hysteresis in theI-Vcurve andC-Vcurve, the hysteresis increases with the increase of hydroxyl groups and also deteriorated the gate leakage current. In contrast, the devices with the PVP : PMF ratio of 5 : 1 dielectric displayed only small hysteresis. According to our experimental results, preventing the possible diffusion of hydroxyl-contained species in polymeric dielectrics is a very important factor in improving the electrical properties of high-performance a-IGZO TFT devices.