Fully epitaxial ferroelectric ScAlN grown by molecular beam epitaxy

We report on the demonstration of ferroelectricity in ScxAl1-xN grown by molecular beam epitaxy on GaN templates. Distinct polarization switching is unambiguously observed for ScxAl1-xN films with Sc contents in the range of 0.14-0.36. Sc0.20Al0.80N, which is nearly lattice-matched with GaN, exhibiting a coercive field of similar to 4.2MV/cm at 10kHz and a remnant polarization of similar to 135 mu C/cm(2). After electrical poling, Sc0.20Al0.80N presents a polarization retention time beyond 10(5) s. No obvious fatigue behavior can be found with up to 3x10(5) switching cycles. The work reported here is more than a technical achievement. The realization of ferroelectric single-crystalline III-V semiconductors by molecular beam epitaxy promises a thickness scaling into the nanometer regime and makes it possible to integrate high-performance ferroelectric functionality with well-established semiconductor platforms for a broad range of electronic, optoelectronic, and photonic device applications.

Automated summary

Ferroelectricity has been successfully demonstrated in ScxAl1-xN epitaxial films grown on GaN templates by molecular beam epitaxy, showing distinct polarization switching and excellent properties, such as a high coercive field and long polarization retention time. This achievement opens up possibilities for integrating high-performance ferroelectric functionality into established semiconductor platforms for various electronic and photonic device applications.