HBAR and their applications

High-overtone Bulk Acoustic Resonators (HBAR) have received a strong interest for many years. Various developments have been particularly achieved using Quartz and AlN materials. With the developments of new materials which present higher coupling electromechanical coefficient, new applications can be address. The fabrication of the proposed HBAR is based on bonding and lapping of two wafers. Thin piezoelectric film presentes strong coupling coefficient, as described previously [1,2]. This fabrication method allows us to choose material for piezoelectric layer and substrat layer to address differents applications.