Scalability Study on Fcrroclcctric-HfO2 Tunnel Junction Memory Based on Non-equilibrium Green Function Method with Self-consistent Potential

Abstract

We have investigated scalability and design guideline of HfO2-bascd Ferroelectric Tunnel Junction (FTJ) memory by employing numerical simulation which is based on Non-Equilibrium Green Function (NEGF) method and self-consistent potential, and calibrated by our experimental FTJ data, for the first time. Metal-Ferroelectric-Insulator-semiconductor (MFIS) FTJ shows a higher TER than Metal-Ferroelectric-Insulator-Metal (MFIM) FTJ with almost the same read current because of the large asymmetry of dielectric screening property in top and bottom electrodes. High read current can be obtained by thinner layers while high TER and low depolarizing field are maintained by adjusting bottom semiconductor electrode property. Based on these results, a guideline for designing MFIS structure FTJ to achieve high read current and high TER has been proposed. We have shown a potential for scaling the FTJ down to sub-20 nm diameter.