PULSE-WIDTH DEPENDENT ACTIVATION VOLTAGE MEASUREMENTS OF FERROELECTRIC (PB,LA)(ZR,TI)O-3 THIN-FILM CAPACITORS FOR NONVOLATILE MEMORIES

We report pulse width and pulse voltage dependent pulse current respon ses of 10% La doped and undoped Pb(Zr0.2Ti0.8)O-3 (PZT) thin film capa citors. With increasing pulse voltage, polarization increases above co ercive voltage, and then saturates at higher voltages. With longer pul se width, polarizations increase and coercive voltages decrease. Activ ation voltages are calculated from the switching current response. La doping effects are discussed in terms of activation voltages for ferro electric domain reversal. 10% La doped PZT (PLZT) has less coercive an d activation voltages and, as a result, pulse polarizations of PLZT ar e less dependent on pulse width and voltage compared to PZT.