Polarization rotation in a ferroelectric BaTiO$_3$ film through low-energy He-implantation

TL;DR

This paper presents a novel method using low-energy He ion implantation to precisely control and engineer ferroelectric domain configurations in BaTiO$_3$ thin films, enhancing their functional properties for electronic and photonic applications.

Contribution

It introduces a post-growth strain engineering technique that selectively modifies ferroelectric domains without affecting the bottom interface, enabling tailored device functionalities.

Findings

Transforming mixed domain states into uniform out-of-plane phases

Improved domain homogeneity and reduced polarization imprint

Enhanced symmetric ferroelectric switching behavior

Abstract

Domain engineering in ferroelectric thin films is crucial for next-generation microelectronic and photonic technologies. Here, a method is demonstrated to precisely control domain configurations in BaTiO$_3$ thin films through low-energy He ion implantation. The approach transforms a mixed ferroelectric domain state with significant in-plane polarization into a uniform out-of-plane tetragonal phase by selectively modifying the strain state in the film's top region. This structural transition significantly improves domain homogeneity and reduces polarization imprint, leading to symmetric ferroelectric switching characteristics. The demonstrated ability to manipulate ferroelectric domains post-growth enables tailored functional properties without compromising the coherently strained bottom interface. The method's compatibility with semiconductor processing and ability to selectively modify specific regions make it particularly promising for practical implementation in integrated devices. This work establishes a versatile approach for strain-mediated domain engineering that could be extended to a wide range of ferroelectric systems, providing new opportunities for memory, sensing, and photonic applications where precise control of polarization states is essential.