Lateral mode suppression in semiconductor bulk acoustic resonator (SBAR) devices using tapered electrodes, and electrodes edge damping materials

摘要

A semiconductor bulk acoustic resonator (SBAR) with improved passband insertion loss and phase performance characteristics is suitable for use in a wide variety of narrowband filtering applications. The SBAR is configured to suppress lateral propagating acoustical wave modes. The lateral acoustical wave modes are controlled by varying the lateral dimension of the resonator electrodes and or utilizing a viscous acoustic damping material, such as a viscoelastic material, such as polyimide, applied along at least a portion of the perimeter of the electrodes to attenuate reflections of the lateral acoustic modes at the electrode edges back into the electrode region.