A single-phase ferroelectric perovskite nitride integrated on silicon

Abstract The integration of ferroelectrics with semiconductors is crucial for developing functional devices, such as field-effect transistors, tunnel junctions, and nonvolatile memories. However, the synthesis of high-quality single crystalline ferroelectric perovskite nitrides has been limited, hindering a comprehensive understanding of their switching dynamics and potential applications. Here we report the synthesis and characterizations of epitaxial single-phase ferroelectric cerium tantalum nitride (CeTaN₃) on silicon. The atomically flat and ultrathin buffer layers provided an excellent template for the epitaxial growth of CeTaN₃. The polar symmetry of CeTaN₃ was confirmed through the atomic displacement of central ions with respect to the center of TaN₆ octahedral and optical second harmonic generation technique. We observed an uneven distribution of ferroelectric microdomains within the films. The remanent polarization of CeTaN₃ reaches 20–25 μC/cm² at room temperature, consistent with theoretical calculations. This work establishes a vital link between ferroelectric perovskite nitrides and their practical applications, paving the way for next-generation information and energy-storage devices with enhanced performance, scalability, and manufacturability.