$\alpha$-In$_2$Se$_3$ based Ferroelectric-Semiconductor Metal Junction for Non-Volatile Memories

TL;DR

This paper combines experimental and theoretical methods to investigate a 2D ferroelectric-semiconductor-metal junction based on $ extalpha$-In$_2$Se$_3$ for non-volatile memory applications, highlighting device behavior and advantages.

Contribution

It introduces a comprehensive simulation framework and experimental validation for $ extalpha$-In$_2$Se$_3$-based FeSMJ devices, demonstrating improved memory performance and scalability.

Findings

Good agreement between simulation and experimental data

vdW gap influences Schottky barrier modulation

Scaling reduces voltage and enhances distinguishability

Abstract

In this work, we theoretically and experimentally investigate the working principle and non-volatile memory (NVM) functionality of 2D $\alpha$-In$_2$Se$_3$ based ferroelectric-semiconductor-metal-junction (FeSMJ). First, we analyze the semiconducting and ferroelectric properties of $\alpha$-In$_2$Se$_3$ van-der-Waals (vdW) stack via experimental characterization and first-principle simulations. Then, we develop a FeSMJ device simulation framework by self-consistently solving Landau-Ginzburg-Devonshire (LGD) equation, Poisson's equation, and charge-transport equations. Based on the extracted FeS parameters, our simulation results show good agreement with the experimental characteristics of our fabricated $\alpha$-In$_2$Se$_3$ based FeSMJ. Our analysis suggests that the vdW gap between the metal and FeS plays a key role to provide FeS polarization-dependent modulation of Schottky barrier heights. Further, we show that the thickness scaling of FeS leads to a reduction in read/write voltage and an increase in distinguishability. Array-level analysis of FeSMJ NVM suggests a 5.47x increase in sense margin, 18.18x reduction in area and lower read-write power with respect to Fe insulator tunnel junction (FTJ).