Preparation and electrical properties of Bi ₂Zn _2/3Nb _4/3O ₇ thin films deposited at room temperature for embedded capacitor applications

Bi ₂Zn _2/3Nb _4/3O ₇ thin films were deposited at room temperature on Pt/Ti/SiO ₂/Si(1 0 0) and polymer-based copper clad laminate (CCL) substrates by pulsed laser deposition. Bi ₂Zn _2/3Nb _4/3O ₇ thin films were deposited in situ with no intentional heating under an oxygen pressure of 4 Pa and then post-annealed at 150°C for 20 min. 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. Bi ₂Zn _2/3Nb _4/3O ₇ thin films deposited on Pt/Ti/SiO ₂/Si(1 0 0) substrates exhibit superior dielectric characteristics. The dielectric constant and loss tangent are 59.8 and 0.008 at 10 kHz, respectively. Leakage current density is 2.5 × 10 ^-7 A/cm ² at an applied electric field of 400 kV/cm. Bi ₂Zn _2/3Nb _4/3O ₇ 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/cm ² at 200 kV/cm.