Modeling of Ferroelectric Switching Excited by Triangular or Sinusoidal Voltage Signals

We model the switching current induced by a trianglar or sinusoidal waveform in a ferroelectric capacitor by exponential growth and decay currents. An exponential current i = I m e t / ( t h 0) or i = I m e m t / ( t S 0) has a total charge of Q = I m . When I m = Ps ( Ps is the saturated spontaneous polarization of a ferroelectric capacitor), a pair of exponential growth and decay currents is used to simulate the polarization reversal of ferroelectric capacitors. We also simulate the hysteresis loop by plotting the time integral of the transient current versus the applied field. Expressing t and in terms of the applied voltage and its change rate, we implement the modeling using SPICE.