Temperature-compensated piezoelectrically actuated Lamé-mode resonators

Abstract

Electrostatically actuated Lamé-mode resonators are known to offer high quality factors (Q) in the low MHz frequency range but require large bias voltages and suffer from low power handling. In this work, we utilize piezoelectric transduction to circumvent the limitations of electrostatic actuation. Silicon dioxide refilled islands, used to achieve temperature compensation, are shown to provide a 20× improvement in the total charge pick-up, enabling piezoelectric actuation of Lamé-mode resonators. By optimizing the placement of the oxide-refilled islands and without changing the total oxide volume, the turnover temperature (TOT) can be designed to occur across a wide range from -40°C to +120°C without any significant Q degradation. Using such an approach multiple piezoelectric resonators with different TOTs can be fabricated on a single wafer, enabling multi-resonator systems stable across a wide temperature range.