Impact of interface traps and fixed interface charges on polarization and TER ratio in MFIS ferroelectric tunnel junctions: A TCAD study

Hafnium dioxide ( HfO 2 )-based ferroelectric tunnel junctions (FTJs) have the potential to dominate the next generation non-volatile memories and neuromorphic computing applications. These devices have been found to be promising memory devices due to their non-destructive readout, CMOS compatibility, and cost-effectiveness. However, the presence of charge trapping/de-trapping and fixed charges can be challenging for read/write operations as they can alter the polarization and cause device variability. This work primarily focuses on the impact of interface traps and fixed charges on the performance of metal-ferroelectric-insulator-semiconductor-based FTJs using technology computer-aided design simulations. This study comprises donor- and acceptor-type traps at the interface of silicon/silicon dioxide ( Si / SiO 2 ) and fixed charges (positive and negative) at the SiO 2 / HfO 2 interface. As indicated by the simulation results, the interface states impact the depolarization field ( E d ) and remanent polarization ( P r ). This eventually affects the read current density (J) and varies the tunneling electroresistance (TER) ratio of the FTJ devices. A comprehensive analysis of the individual and combined effects of interface traps and fixed interface charges highlights their critical role in determining key FTJ performance metrics.