High k PVP titanium dioxide composite dielectric with low leakage current for thin film transistor

Titanium dioxide (TiO2) dielectric has the potential to achieve low cost and low energy consumption in the area of Thin Film Transistor (TFT) due to its high relative dielectric constant. However, the large leakage current limits its application. In this paper, Polyvinylpyrrolidone (PVP) modified TiO2 composite dielectric was prepared by the sol-gel method with a series of PVP concentrations. With increasing PVP concentration, the roughness, thickness and band gap increased, the leakage current density first decreased and then increased, while the area capacitance and the relative dielectric constant (k) decreased. After comparison, 0.05 wt% was the optimal modification concentration. TiO2: 0.05 wt % PVP composite film had smooth morphology and low roughness. The leakage current density of the Metal-Insulator-Metal (MIM) device (with the composite film as the insulator layer) was as low as 6.88 × 10−9 A/cm2 (at 1 MV/cm), and k is 69.7. PVP modified TiO2 composite film showed good dielectric characteristics and satisfied the development trend of low leakage current and low energy consumption devices.