AlScN‐on‐SiC microelectromechanical Lamb wave resonators operating at high temperature up to 800 °C.

This article focuses on the experimental demonstration of aluminum scandium nitride (AlScN)-on-cubic silicon carbide (3C-SiC) Lamb wave resonators (LWRs) fabricated via microelectromechanical systems (MEMS) technology, which operate reliably at high temperatures up to 800 °C. The devices maintain robust electromechanical resonance near 27 MHz with a quality factor (Q) of approximately 900 even at 800 °C, showing consistent and stable performance through multiple thermal cycles in moderate vacuum conditions. The study highlights that Q remains stable below 400 °C but declines at higher temperatures due to thermoelastic damping and intrinsic material losses. These findings demonstrate the suitability of AlScN-on-SiC MEMS LWRs for high-temperature and harsh-environment applications, addressing critical challenges in material selection and device stability for sectors such as aerospace, automotive, and energy.