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Bismuth zinc niobate (BZN) thin films with excess Zn contents were deposited from the ceramic targets containing various excess amounts of ZnO (0–20 mol%) on Pt/TiO 2 /SiO 2 /Si substrate by RF magnetron sputtering at room temperature. As-deposited thin films were post-annealed at a temperature ≤200 °C, which is compatible with PCB substrates. The effect of Zn deficiency and Zn excess on the microstructure, dielectric, and electrical properties of BZN thin films was studied. As-deposited and post-annealed BZN thin films at a temperature ≤200 °C were amorphous in nature. An appropriate amount of excess zinc improves the dielectric and electrical properties of BZN thin films, while too much excess zinc leads to deteriorate the properties. BZN thin film with 5 mol% excess Zn content exhibits the maximum dielectric constant of 64 with a very low loss of 0.6%, measured at 10 kHz and the leakage current of less than 1 µA at an applied electric field of 200 kV/cm. [ABSTRACT FROM AUTHOR]

Abstract: Bi2Zn2/3Nb4/3O7 thin films were deposited at room temperature on Pt/Ti/SiO2/Si(100) and polymer-based copper clad laminate (CCL) substrates by pulsed laser deposition. Bi2Zn2/3Nb4/3O7 thin films were deposited in situ with no intentional heating under an oxygen pressure of 4Pa and then post-annealed at 150°C for 20min. It was found that the films are still amorphous in nature, which was confirmed by the XRD analysis. It has been shown that the surface roughness of the substrates has a significant influence on the electrical properties of the dielectric films, especially on the leakage current. Bi2Zn2/3Nb4/3O7 thin films deposited on Pt/Ti/SiO2/Si(100) substrates exhibit superior dielectric characteristics. The dielectric constant and loss tangent are 59.8 and 0.008 at 10kHz, respectively. Leakage current density is 2.5×10−7 A/cm2 at an applied electric field of 400kV/cm. Bi2Zn2/3Nb4/3O7 thin films deposited on CCL substrates exhibit the dielectric constant of 60 and loss tangent of 0.018, respectively. Leakage current density is less than 1×10−6 A/cm2 at 200kV/cm. [Copyright &y& Elsevier]