18-MHz Silicon Lamé Mode Resonators With Corner and Central Anchor Architectures in a Dual-Wafer SOI Technology

This paper presents Lamé bulk mode square resonators fabricated in a novel silicon-on-insulator technology, MicraGEM-Si. Structures are formed by patterning two wafers with several etched depths and wafer bonding them to create the released movable resonator structures. Two distinct anchoring architectures are studied: one with suspension beams at the nodal corner points, and the other with a central anchoring support. The center support architecture can be suitable for realizing high-performance gyroscopes. Resonators with different support sizes are fabricated and characterized. Fabricated devices were measured to operate at a resonance frequency of ~18 MHz and quality factors as high as ~42000 in atmospheric pressure, which to the best of our knowledge is the highest reported to date at such an ambient pressure, and ~871000 in 100-mtorr vacuum, corresponding to a f·Q product of ~1.6×10
¹³
.