Controlled ferroelectric switching in ultrawide bandgap AlN/ScAlN multilayers

Abstract

Ultrawide bandgap ferroelectric nitride semiconductors have shown promising applications in electronic, micromechanical, and optical devices. Current studies, however, have largely been focused on single layer ferroelectric nitrides. Controlled polarization switching in artificial multilayer composite structures, such as ferroelectric/piezoelectric or ferroelectric/dielectric heterostructures, provides additional dimension for engineering their properties and improving device performance and functionality. Here, we demonstrate controlled ferroelectric switching in an AlN/ScAlN/AlN trilayer structure grown by molecular beam epitaxy. The trilayer showed large switchable polarization with reasonable endurance and retention performance. Polarity-sensitive wet etching further confirmed the controlled switching in the clamped ScAlN layer. The ability to control the polarity switching in ScAlN/AlN multilayers offers an intriguing avenue for the design and development of next-generation electronic, piezoelectronic, and ferroelectric devices.