A Physics-Based Dynamic Model of HfO₂-Based Ferroelectric Tunnel Junctions With Dual-Insulator Structure

A physics-based compact model for the metal-ferroelectric–insulator-metal (MFIM) tunneling junctions, compatible with metal-ferroelectric–metal (MFM) structures, is developed to cover their essential dynamic features. The dual-insulator introduces a complex shape of tunneling barriers, which also exhibits a dependence on the history of ferroelectric (FE) polarization. Voltage control of the ferroelectric tunnel junction (FTJ) is formulated using the dynamic nucleation-limited switching theory. Key operational voltages are analyzed, especially for those with zero internal fields. The tunneling transport is analytically formulated, covering the dual-insulator barriers and the above special bias points based on the Wentzel-Kramers–Brillouin (WKB) approximations. The developed model, validated against both experimental data and TCAD simulations, demonstrates key features of the developed model including quasi-static and dynamic state transitions, historical dependence, and time-modulated multiple states. This model provides a unified framework for the simulation and optimization of both MFIM and MFM tunnel junctions, facilitating their potential applications in nonvolatile memory (NVM) and neuromorphic computing.