Effects of O₂/Ar Ratio on Preparation and Dielectric Properties of CaZrO₃ Films by Radio Frequency (RF) Magnetron...

CaZrO₃ (CZO) thin films were deposited on Pt/Ti/SiO₂/Si substrates at 450 °C by radio-frequency magnetron sputtering technology. The microstructures and dielectric properties of CZO thin films were investigated. X-ray diffraction analysis reveals that the perovskite orthogonal CZO phase would be promoted by a higher O₂ partial pressure in the flow ratio of O₂/Ar after thin films were annealed at 700 °C for 3 h in air. The films prepared under the flow ratio of O₂/Ar (20:40, 30:40 and 40:40) show the main perovskite crystal phase of CaZrO₃ with a small amount of Ca₀.₂Zr₀.₈O₁.₈. The main crystal phase was Ca₀.₂Zr₀.₈O₁.₈ when the film was deposited under an O₂/Ar ratio of 40:10. The annealed film with a 40:40 O₂/Ar ratio exhibits a dielectric performance with a high dielectric constant (εr) of 25 at 1 MHz, a temperature coefficient of permittivity of not more than 122.7 ppm/°C from 0 °C to 125 °C, and a low leakage current density of about 2 × 10^-7 A/cm² at 30 V with an ohmic conduction mechanism.