Ferroelectric AlBN Films by Molecular Beam Epitaxy

TL;DR

This paper demonstrates ferroelectric properties in AlBN thin films grown by molecular beam epitaxy, highlighting their potential for integration in electronic and photonic devices due to their wide bandgap and ferroelectric behavior.

Contribution

First report of ferroelectric AlBN films grown by molecular beam epitaxy on Nb2N electrodes, showing ferroelectric switching and potential for device integration.

Findings

Ferroelectric switching observed in AlBN films with increasing Boron content.

Measured remnant polarization Pr of 15 μC/cm² and coercive field Ec of 1.45 MV/cm.

AlBN films retain ultrawide bandgap and can be integrated with GaN and AlN semiconductors.

Abstract

We report the properties of molecular beam epitaxy deposited AlBN thin films on a recently developed epitaxial nitride metal electrode Nb2N. While a control AlN thin film exhibits standard capacitive behavior, distinct ferroelectric switching is observed in the AlBN films with increasing Boron mole fraction. The measured remnant polarization Pr of 15 uC/cm2 and coercive field Ec of 1.45 MV/cm in these films are smaller than those recently reported on films deposited by sputtering, due to incomplete wake-up, limited by current leakage. Because AlBN preserves the ultrawide energy bandgap of AlN compared to other nitride hi-K dielectrics and ferroelectrics, and it can be epitaxially integrated with GaN and AlN semiconductors, its development will enable several opportunities for unique electronic, photonic, and memory devices.