PZT transduction of high-overtone contour- mode resonators

This paper presents the Butterworth-van Dyke model and quantitative comparison that explore the design space of lead zirconate titanate-only (PZT) and PZT on 3-, 5-, and 10-μm single-crystal silicon (SCS) high-overtone widthextensional mode (WEM) resonators with identical lateral dimensions for incorporation into radio frequency microelectromechanical systems (RF MEMS) filters and oscillators. A novel fabrication technique was developed to fabricate the resonators with and without a silicon carrier layer using the same mask set on the same wafer. The air-bridge metal routings were implemented to carry electrical signals while avoiding large capacitances from the bond-pads. We theoretically derived and experimentally measured the correlation of motional impedance (R
_X
), quality factor (Q), and resonance frequency (f) with the resonators' silicon layer thickness (t
_Si
) up to frequencies of operation above 1 GHz.