Effective Evaluation Strategy Toward Low Temperature Solution-Processed Oxide Dielectrics for TFT Device

Abstract

Solution-processed oxide dielectrics are widely studied as alternatives to SiO2, SiNx in thin film transistors for high capacitance and low energy consuming. However, it's still a challenge to achieve high quality of solution-processed oxide dielectrics TFT by low-temperature post-treatment. Here, an effective strategy is proposed to evaluate low temperature solution-processed ZrO2 TFT in terms of uniformity, film density and electrical performance by employing TG/DSC, drop analyzer, XRR and a novel μ-PCD measurement. Particularly, μ-PCD measurement provides valuable information on homogeneity and defect level. The optimized device with ZrNO3 as dielectric precursor and ethyl alcohol as solvent through spin coating process annealed at 200°C shows a saturation mobility of 8.6 cm2V-1S-1, Ion/Ioff ratio about 1.1×106, subthreshold swing about 334 mV/decade with a low leakage current density of 5×10-5 A/cm2 at 10V. This article offers a convenient way for precursor optimization towards low leakage current and high homogeneity solution-processed oxide dielectrics for TFT devices.

Keywords

• TFT
• solution-processed
• oxide dielectric
• microwave photoconductivity decay
• subthreshold swing (SS)