Piezoelectric-on-semiconductor Micromechanical Resonators With Linear Acoustic Bandgap Tethers

Abstract

Microelectromechanical resonators include a resonator body anchored to a substrate by at least one tether containing a coupled-ring linear acoustic bandgap structure therein. The coupled-ring linear acoustic bandgap structure can include a plurality of piezoelectric-on-semiconductor rings connected together by a plurality of piezoelectric-on-semiconductor tether segments. A first electrode may also be provided, which extends on the resonator body and the coupled-ring linear acoustic bandgap structure. This resonator body, which may be suspended opposite a recess in the substrate, may include a semiconductor (e.g., silicon) body having a piezoelectric layer (e.g., AlN) thereon, which extends between the semiconductor body and the first electrode. The coupled-ring linear acoustic bandgap structure may be a periodic structure, where a pitch between each of the plurality of piezoelectric-on-semiconductor rings in the at least one tether is equivalent, or a non-periodic structure.