Structural and dielectric properties of calcium doped bismuth zinc niobate thin films prepared by pulsed laser deposition at room temperature

(Bi1.5Zn0.1Ca0.4)(Zn0.5Nb1.5)O7 (BZNCa) thin films were prepared by pulsed laser deposition on Pt/TiO2/SiO2/Si substrates at room temperature. The as-deposited films and films post-annealed from 100 °C to 175 °C for 10 min in air are all amorphous. The influence of the post-annealing process on structural and electrical properties was investigated. The surface morphology of BZNCa films remains almost same with the annealing temperature. While the dielectric and leakage-current properties of the films are strongly influenced by the annealing temperature. The film deposited at O2 pressure of 4 Pa and then post-annealed at 150 °C shows the improved dielectric and leakage-current characteristics. The dielectric constant and loss tangent are 67.2 and 0.03 at 100 kHz, respectively. The leakage current density is less than 1 µA/cm2 at an applied bias electric field of 400 kV/cm. The results indicate that calcium doped BZN thin films have potential applications for embedded capacitors.