CHARACTERIZATION OF FERROELECTRIC SRBI2TA2O9 THIN-FILMS DEPOSITED BY A RADIO-FREQUENCY MAGNETRON SPUTTERING TECHNIQUE

Fatigue-free Bi-layer SrBi2Ta2O9 films were deposited on Pt/Ti/SiO2/Si substrates by radio frequency magnetron sputtering. The addition of 3 0 mole percent (m/o) SrCO3 and 20 m/o Bi2O3 into the target was necess ary in order to compensate for the lack of Sr and Bi in the films. A 2 00 nm thick Sr0.7Bi2.0Ta2.0O9 film annealed at 800 degrees C exhibited dense morphology, a dielectric constant of 210, and a dissipation fac tor of 0.06 at a frequency of 1 MHz. The remnant polarization 2P, and the coercive field 2E(c) of the films were 9.1 mu C/cm(2) and 85 kV/cm , respectively, at an applied voltage of 5 V. The leakage current dens ity was about 7 x 10(-7) A/cm(2) at 150 kV/cm. The films showed fatigu e-free characteristics under a +/-5 V bipolar square pulse of 1 MHz up to 1.0 x 10(10) Hz. The SrBi2Ta2O9 films prepared by radio frequency magnetron sputtering are attractive for application to nonvolatile mem ory devices.