Dielectric properties of pulsed-laser deposited SrTiO3 films at microwave frequency ranges

The dielectric constant and loss tangent of SrTiO3 thin films were characterized under the influence of an applied dc voltage at about 3.64 GHz. The measurement was carried out utilizing a gold resonator with a flip-chip capacitor at cryogenic temperatures. The analysis of the experimentally observed capacitance and quality factor served to give a measure of the dielectric constants and the loss tangents of the SrTiO3 film at microwave ranges, respectively. A dielectric constant of 830 and a low loss tangent of 6x10(-3) at 3.64 GHz were observed at 90 K and 100 V. The dielectric loss decreases as the bias voltage increases. In addition, the quality of the SrTiO3 film is presented in terms of fractional frequency under the bias voltages and cryogenic temperatures. (C) 2000 American Institute of Physics. [S0021-8979(00)07717-3].