Zero TCF resonator based on S0 Lamb wave mode in AlN thin plate films

摘要

Resonator based S₀ Lamb wave mode in AlN thin films plate has drawn great attentions thanks to its high phase velocity up to 10 km/s and large electromechanical coupling coefficient (K2). Moreover, this structure allows operation at high temperature conditions. Although several significant research efforts are ongoing to enable AlN-based piezoelectric devices for high temperature applications, an outstanding challenge in AlN-based resonators is to obtain the excellent frequency-temperature stability at operating temperatures [1]. The AlN/SiO₂ composite membrane was proposed as a solution for thermal compensation but with the counterpart of degrading K2 and quality factor. In this work we propose an original structure leading to a better compromise between temperature coefficient of frequency (TCF) value and resonator performances.