Kinetic control of ferroelectricity in ultrathin epitaxial Barium Titanate capacitors

TL;DR

This study demonstrates how controlling plasma plume kinetics during pulsed laser deposition enables the fabrication of ultrathin BaTiO3 ferroelectric capacitors with exceptional electrical performance, suitable for low-voltage electronic applications.

Contribution

It introduces a novel fabrication approach that enhances ultrathin ferroelectric device quality and performance, addressing previous limitations in scaling and reliability.

Findings

Ultralow switching voltages (<0.3 V) achieved in 20 nm BaTiO3 films

Long retention times (>10^4 seconds) demonstrated

High endurance (>10^11 cycles) in ultrathin ferroelectric capacitors

Abstract

Ferroelectricity is characterized by the presence of spontaneous and switchable macroscopic polarization. Scaling limits of ferroelectricity have been of both fundamental and technological importance, but the probes of ferroelectricity have often been indirect due to confounding factors such as leakage in the direct electrical measurements. Recent interest in low-voltage switching electronic devices squarely puts the focus on ultrathin limits of ferroelectricity in an electronic device form, specifically on the robustness of ferroelectric characteristics such as retention and endurance for practical applications. Here, we illustrate how manipulating the kinetic energy of the plasma plume during pulsed laser deposition can yield ultrathin ferroelectric capacitor heterostructures with high bulk and interface quality, significantly low leakage currents and a broad "growth window". These heterostructures venture into previously unexplored aspects of ferroelectric properties, showcasing ultralow switching voltages ($<$0.3 V), long retention times ($>$10$^{4}$s), and high endurance ($>$10$^{11}$cycles) in 20 nm films of the prototypical perovskite ferroelectric, BaTiO$_{3}$. Our work demonstrates that materials engineering can push the envelope of performance for ferroelectric materials and devices at the ultrathin limit and opens a direct, reliable and scalable pathway to practical applications of ferroelectrics in ultralow voltage switches for logic and memory technologies.