A Dynamic Compact Model for Ferroelectric Capacitance

A non-quasi-static model for ferroelectric capacitance is developed in this letter. A state transition in the voltage and time domains between two polarization states is formulated first. The quasi-static model is derived from the state transition of voltage domain, and supports the minor loops. Different from the Preisach model, an initial state is supported, and the modulated coercive voltages are responsible for minor loops. The non-quasi -static model is then derived with the state transition in the time domain, similar to a relaxation approximation in MOSFET modeling. The non-quasi-static model reproduces the saturation loop, minor loops, the frequency-dependent characteristics of measured ferroelectric capacitances, with their origins explained from polarization switching relaxation. The pulse width dependent switching is well reproduced with the model.