Optical and Dielectric Properties and Microstructures of rf-Magnetron Sputtered ZnO-Doped Zr0.8Sn0.2TiO4 Films on Indium Tin Oxide/Glass Substrates

Abstract

Optical and dielectric properties and microstructures of ZnO-doped (Zr0.8Sn0.2)TiO4 thin films prepared by radiofrequency (rf)-magnetron sputtering on indium tin oxide/glass substrates at different rf powers and substrate temperatures have been investigated. Selected-area diffraction patterns showed that the deposited films exhibited a polycrystalline microstructure. All films exhibited the ZnO-doped (Zr0.8Sn0.2)TiO4 structure with the (111) orientation perpendicular to the substrate surface. The grain size as well as the deposition rate of the film increased with an increase in both rf power and substrate temperature. At an annealing temperature of 700°C, the ZnO-doped (Zr0.8Sn0.2)TiO4 film possessed a dielectric constant of 47 at 10 MHz, a dissipation factor of 0.02 at 10 MHz, a leakage current density of 7.35 × 10−9 A/cm2 at an electrical field of 1 kV/cm, average transmission in the visible range of over 70%, and an optical bandgap of 3.6 eV. This film will allow fabrication of fully transparent semiconductor devices such as a resistive random-access memory (RRAM) and thin-film transistors (TFTs) completely based on ZnO-doped (Zr0.8Sn0.2)TiO4 thin films.