Voltage tunable dielectric properties of rf sputtered Bi2O3-ZnO-Nb2O5 pyrochlore thin films

Abstract The Bi2O3-ZnO-Nb2O5 (BZN) pyrochlore thin films were prepared on platinized Si substrates using a reactive rf magnetron sputtering. The structures, surface morphologies, dielectric properties and voltage tunable dielectric properties of films with deposition parameters were investigated. The sputter deposited BZN pyrochlore thin films have a cubic pyrochlore phase and secondary phases of zinc niobate and bismuth niobate when crystallized at 600∼800 °C. The dielectric constant and tunability of thin films changed with an O2/Ar ratio and post-annealing temperature. The BZN pyrochlore thin films sputtered in 15% O2 and annealed at 700 °C had a dielectric constant of 153, tan δ of ∼0.003 and maximum tunability of 14% at 1000 kV/cm of dc bias field under 1 MHz.