ANALYSIS OF FATIGUE CHARACTERISTICS IN FE-DOPED PB(ZR0.52TI0.48)O-3 THIN-FILMS BY SWITCHING CURRENTS

The polarization fatigue for ferroelectric Pb(Zr0.52Ti0.48)O-3 (PZT) t hin films has a known relation with oxygen vacancies occurring in the films during fabrication processes. Fe-doped PZT thin films were inten tionally deposited with consideration for the effects of oxygen vacanc ies regarding fatigue using rf-magnetron sputtering. The remanent pola rization is suppressed to half its initial value after 10(9) bipolar s witching cycles. From the observance of the switching currents with co nsideration to applied voltages, switching characteristics in the film s were studied by fitting using the Kolmogorov-Avrami (K-A) theory. It was revealed from the switching currents as a function of fatigue cyc les that the quantity of switched charges decreased with increasing sw itching cycles, but the dimensionality with respect to domain growth w as unchanged as compared to its initial value. The velocities of domai n wall motions before and after fatigue were also unchanged, indicatin g that the motion of the domain walls by applied pulse voltages was no t an additional obstacle concerning fatigue processes. Therefore,in th e case of polarization fatigue by subjecting to electric cycles; the d omain states in these films may not be affected by the fatigue.