Polarization switching in thin doped HfO2 ferroelectric layers

Abstract

The deployment of ferroelectrics in device concepts such as Ferroelectric Random Access Memory and Ferroelectric Field Effect Transistors requires a good understanding of the polarization switching mechanisms. While several reports already exist involving classical perovskite ferroelectrics, only recently has the switching dynamics in HfO2-based layers started to be addressed. In this work, the Kolmogorov–Avrami–Ishibashi (KAI), the Nucleation Limited Switching (NLS), the Landau–Khalatnikov (LK), and the Inhomogeneous Field Mechanism (IFM) models for polarization switching are surveyed and evaluated with the existing body of literature. Data concerning NLS and IFM are compared to experiments undertaken in this study. After excluding the KAI model because of considerations dealing with film morphology and domain wall energy, we conclude that the NLS, the LK, and the IFM models do not necessarily mutually exclude each other, but rather give a diverse perspective on the switching phenomenon based on thermodynamic, kinetic, statistic, microscopic, and/or macroscopic points of view.