Enhanced ferroelectricity in epitaxial Hf0.5Zr0.5O2 thin films integrated with Si(001) using SrTiO3 templates

TL;DR

This study demonstrates that epitaxial Hf0.5Zr0.5O2 thin films grown on Si(001) via SrTiO3 templates exhibit enhanced ferroelectric properties, long-term retention, and high endurance, enabling potential integration into silicon-based memory devices.

Contribution

The paper introduces a novel epitaxial growth method using SrTiO3 templates to enhance ferroelectricity in Hf0.5Zr0.5O2 films on silicon, surpassing previous limitations.

Findings

High remnant polarization of 34 μC/cm² in thin films

Long retention time exceeding 10 years at 4 V

Endurance up to 10^9 switching cycles

Abstract

SrTiO3 templates have been used to integrate epitaxial bilayers of ferroelectric Hf0.5Zr0.5O2 and La2/3Sr1/3MnO3 bottom electrode on Si(001). The Hf0.5Zr0.5O2 films show enhanced properties in comparison to equivalent films on SrTiO3(001) single crystalline substrates. The films, thinner than 10 nm, have very high remnant polarization of 34 uC/cm2. Hf0.5Zr0.5O2 capacitors at operating voltage of 4 V present long retention time well beyond 10 years and high endurance against fatigue up to 109 cycles. The robust ferroelectric properties displayed by the epitaxial Hf0.5Zr0.5O2 films on Si(001) using SrTiO3 templates paves the way for the monolithic integration on silicon of emerging memory devices based on epitaxial HfO2.