Work

Aluminum Scandium Nitride as a Functional Material at 1000 °C

Year: 2025

Type: article

Abstract: Aluminum scandium nitride (AlScN) has emerged as a highly promising material for high‐temperature applications due to its robust piezoelectric, ferroelectric, and dielectric properties. This study investigates the behavior of Al0.7Sc0.3N thin films in extreme thermal environments, demonstrating functional stability up to 1000 °C, making it suitable for use in aerospace, hypersonics, deep‐well, and nuclear reactor systems. Tantalum silicide (TaSi2)/Al0.7Sc0.3N/TaSi2 capacitors are fabricated and characterized across a wide temperature range, revealing robust ferroelectric and dielectric properties, along with significant enhancement in piezoelectric performance. At 1000 °C, the ferroelectric hysteresis loops showed a substantial reduction in coercive field from 4.3 to 1.2 MV cm−1, while the longitudinal piezoelectric coefficient increased nearly tenfold, reaching 75.1 pm V−1 at 800 °C. Structural analysis via scanning and transmission electron microscopy confirmed the integrity of the TaSi2/Al0.7Sc0.3N interfaces, even after exposure to extreme temperatures. Furthermore, the electromechanical coupling coefficient is calculated to increase by over 500%, from 12.9% at room temperature to 82% at 700 °C. These findings establish AlScN as a versatile material for high‐temperature ferroelectric, piezoelectric, and dielectric applications, offering unprecedented thermal stability and functional enhancement.

Source: Advanced Electronic Materials

DOI: 10.1002/aelm.202400849