Switching kinetics of lead zirconate titanate submicron thin-film memories

Abstract

We have measured coercive field and switching voltage versus thickness in PbZr_0.54Ti_0.46O₃ thin (0.15–0.50 μm) films, together with switching times and current transient shapes versus field and temperature. The results show activation fields of order 120 kV/cm at room temperature, threshold voltages below 1.3 V, and switching speeds faster than 100 ns, demonstrating that fast, nonvolatile memories can be constructed that are compatible with standard silicon or GaAs integrated circuit voltage levels, without the need for an internal voltage pump. The displacement current transient data yield 2.5 as the dimensionality of domain growth if one‐step intial nucleation rate is assumed, and are compatible with the theory of Ishibashi, yielding i_maxt_max/P_s=1.65±0.23, in comparison with the predicted 1.646. The switching time exhibits an activation field dependence upon both voltage and temperature through a single reduced parameter (T_C−T)(VT_C),⁻¹ in accord with the theory of Orihara and Ishibashi.