A 1.14GHz piezoelectrically transduced disk resonator

This paper presents the design, simulation, fabrication, and testing results of a 1.14GHz piezoelectrically actuated disk resonator with electrostatic frequency tuning capability. The resonator is designed to suppress anchor loss by minimizing the number of anchor beams as well as their sizes. Split-top electrodes are used to drive the target mode and to achieve maximum electromechanical coupling while minimizing motional resistance. The devices are fabricated from SOI wafers using a 6-mask process, avoiding the need to deposit the structural silicon layer and sacrificial oxide layer. As a result, the maximum processing temperature is kept below 250°C, allowing post-CMOS compatibility. The highest measured resonant frequency is 1.14GHz at the third mode from a disk resonator of 30μm diameter. Preliminary measurements indicated quality factors (Q) ranging from 85 to 215 for the one-port device under atmospheric pressure.