Structural and dielectric properties of Bi2Zn2/3Nb4/3O7 thin films prepared by pulsed laser deposition at low temperature for embedded capacitor applications

Abstract: Bi2Zn2/3Nb4/3O7 thin films were deposited on Pt/TiO2/SiO2/Si(100) substrates at a room temperature under the oxygen pressure of 1–10Pa by pulsed laser deposition. Bi2Zn2/3Nb4/3O7 thin films were then post-annealed below 200°C in a rapid thermal process furnace in air for 20min. The dielectric and leakage current properties of Bi2Zn2/3Nb4/3O7 thin films are strongly influenced by the oxygen pressure during deposition and the post-annealing temperature. Bi2Zn2/3Nb4/3O7 thin films deposited under 1Pa oxygen pressure and then post-annealed at a temperature of 150°C show uniform surface morphologies. Dielectric constant and loss tangent are 57 and 0.005 at 10kHz, respectively. The high resolution TEM image and the electron diffraction pattern show that nano crystallites exist in the amorphous thin film, which may be the origin of high dielectric constant in the Bi2Zn2/3Nb4/3O7 thin films deposited at low temperatures. Moreover, Bi2Zn2/3Nb4/3O7 thin film exhibits the excellent leakage current characteristics with a high breakdown strength and the leakage current density is approximately 1×10−7 A/cm2 at an applied bias field of 300kV/cm. Bi2Zn2/3Nb4/3O7 thin films are potential materials for embedded capacitor applications. [Copyright &y& Elsevier]