EFFECT OF ANNEALING METHOD TO CRYSTALLIZE ON SR0.9BI2.3TA2O9-FILM PROPERTIES FORMED FROM ALKOXIDE SOLUTION(ALPHA THIN)

Sr0.9Bi2.3Ta2O9+alpha (SBT) thin films were formed from a mixed alkoxi de solution and were heat-treated by various annealing methods. The SE T thin film heat-treated with the standard temperature rising at a rat e of 10 degrees C/min (standard thermal annealing: STA) showed higher squareness (effective remanent polarization/effective saturation polar ization) and effective remanent polarization values than those of the film heat-treated with a rapid temperature rise at a rate of 125 degre es C/s (rapid thermal annealing: RTA). This difference was large in th e region of low applied voltage. The low values of the SET film with R TA treatment were caused by lower crystal continuity in the direction of film thickness than that of the SET film with STA treatment. The SE T film with RTA treatment showed a higher leakage current density for the entire applied voltage region than that of the film with STA treat ment. The higher leakage current density was caused by fine nonstoichi ometric (Bi-rich) particles which exist at grain boundaries of large g rains. Therefore, it was concluded that the high squareness ratio and low leakage current density are obtained in SBT film which has only on e grain in the film thickness direction and does not have nonstoichiom etry fine particles around grain boundaries.