Implementation of a ferroelectric capacitor model using the Preisach hysteresis theory

The design of the new ferroelectric memories requires a ferroelectric capac itor model that should be easy to incorporate in a circuit simulator and ea sy to calibrate based on the experimental measurements. Such a model can be developed by applying the Preisach theory of hysteresis to ferroelectric m aterials. This theory assumes a distribution of the ferroelectric coercitiv e voltages. This paper presents the Preisach model and its implementation f or the ferroelectric materials based on the experimental determination of t he bidimensional Preisach distribution. The relaxation current of the ferro electric capacitor is also incorporated in the model. Relaxation plays an i mportant roll in the frequency response of these materials. The whole model was implemented into the Spectre(R) circuit simulator. The simulations of the hysteresis loops show a good agreement with the experiment even for par tial hysteresis loops. The memory cell simulations show that the model can be successfully used for the real memory design.