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

Bi2Zn2/3Nb4/3O7 thin films were deposited on Pt/TiO2/SiO2/Si( 1 0 0) substrates at a room temperature under the oxygen pressure of 1-10 Pa by pulsed laser deposition. Bi2Zn2/3Nb4/3O7 thin films were then post-annealed below 200 degrees C in a rapid thermal process furnace in air for 20 min. 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 1 Pa oxygen pressure and then post-annealed at a temperature of 150 degrees C show uniform surface morphologies. Dielectric constant and loss tangent are 57 and 0.005 at 10 kHz, 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 x 10(-7) A/cm(2) at an applied bias field of 300 kV/cm. Bi2Zn2/3Nb4/3O7 thin films are potential materials for embedded capacitor applications. (C) 2011 Elsevier B.V. All rights reserved.