Electrical characteristics of dip coated TiO 2 thin films with various withdrawal speeds for resistive switching applications

Abstract

TiO 2 thin films were coated on p-Si (100) substrate by sol gel dip coating method by varying the withdrawal speed from 1 cm/min to 4 cm/min. Post-deposition annealing of all the samples were carried out at 500 °C in air ambient. Uniform surface morphology has been observed for all the samples. The intensity of XRD peak corresponding to the anatase phase of TiO 2 was found to be increased with the rise in withdrawal speed. The formation of titania was also confirmed by the FTIR study. Capacitance-voltage and current-voltage measurements were carried out by fabricating Al/TiO 2 /Si metal oxide semiconductor (MOS) structure. Oxide charge density (Q ox ) was calculated from the shift in flatband voltage and was found to be decreased with the increase in withdrawal speed. Interface trap density (D it ) was estimated to be 2.1 × 10 −12 eV −1 cm −2 for withdrawal speed of 1 cm/min. The film deposited at the withdrawal speed of 1 cm/min has shown better bipolar resistive switching behavior with an enhanced resistive window in both the polarities.