Single crystal aluminum nitride film bulk acoustic resonators

In recent years, film bulk acoustic resonators (FBARs) have become important in the mobile handset market for their small size compared to surface acoustic wave resonators, their compatibility with existing integrated circuit processes, and their usage in synthesizing components such as filters and duplexers. In this work, we demonstrate through finite element simulation using COMSOL MultiPhysics and experimental data, that single crystal FBARs outperform current polycrystalline devices with their higher mechanical coupling efficiency and quality factor. We also present elasticity coefficients extracted from experimental data on fabricated devices.