Fabrication and Characterization of ZnO-Based Film Bulk Acoustic Resonator with a High Working Frequency

We report on the fabrication and characterization of a ZnO-based film-bulk acoustic-resonance device utilized as biosensor. The device has a multilayer structure which consists of piezoelectric element (Au/ZnO/Pt) and a Bragg-reflection-layer acoustic isolation consisting of multilayers of ZnO/Pt. Dielectric measurements have revealed that the device has a very high working frequency (up to ～3.1GHz), meaning that the device may have a higher sensitivity than the devices reported in the literature.