Investigating Ferroelectric Minor Loop Dynamics and History Effect-Part II: Physical Modeling and Impact on Neural Network Training

Doped HfO2-based ferroelectric field-effect transistor (FeFET) is being actively explored as an emerging nonvolatile memory device with the potential for in-memory computing. In this work, we identify a new challenge of ferroelectric partial switching, namely history effect in minor loop dynamics. We experimentally demonstrate the minor loop dynamics in both ferroelectric capacitor (FeCap) and 28-nm FeFET in Part I. In this article, a physics-based phase-field multidomain switching model is used to understand the origin. Even though the device may have the same polarization state that is externally observable, its internal domain configuration varies depending on its history. We model such history effect into the FeFET-based neural network simulation and analyze its negative impact on the training accuracy and then propose a possible mitigation strategy.