Temperature dependence of the electrical properties of SrBi2Ta2O9 thin films deposited by radio-frequency magnetron sputtering

Fatigue-free bilayered SrBi2Ta2O9 (SBT) films were prepared on Pt/Ti/SiO2/Si substrates by rf magnetron sputtering. The applied voltage showing maximum capacitance decreases with increasing temperature. The remanent polarisation and the coercive field obtained for the SBT films were 13 microC/cm2 and 128 kV/cm at an applied voltage of 5 V at 30 C. The films measured at room temperature and 100 C showed fatigue-free-characteristics up to 10 exp(11) cycles under 5 V bipolar square pulses. SBT films show a retention loss of only 6% after 10 years at 100 C. The leakage current density is less than 4.5 x 10 exp(-7) microA/cm2 at an applied voltage of 3 V at 75 C. The dominant transport mechanism of SBT films was an interface limited Schottky emission. The Pt/SBT contacts have a Schottky barrier height of 0.8-1.04 eV. 21 refs.