Bulk mode microelectromechanical resonator devices and methods

摘要

Micromachined microelectromechanical systems (MEMS) based resonators offer integration with other MEMS devices and electronics. Whilst piezoelectric film bulk acoustic resonators (FBAR) generally exhibit high electromechanical transduction efficiencies and low signal transmission losses they also suffer from low quality factors and limited resonance frequencies. In contrast electrostatic FBARs can yield high quality factors and resonance frequencies but suffer from increased fabrication complexity. lower electromechanical transduction efficiency and significant signal transmission loss. Accordingly, it would be beneficial to overcome these limitations by reducing fabrication complexity via a single metal electrode layer topping the resonator structure and supporting relatively low complexity/low resolution commercial MEMS fabrication processes by removing the fabrication requirement for narrow transduction gaps. Beneficially, embodiments of the invention provide MEMS circuits with electrostatic tuning and provide resonator designs combining the advantages of piezoelectric actuation and bulk-mode resonators.