Drive and Control This paper presents the fabrication and testing of a high aspect-ratio 80um tall polysilicon ring gyroscope (PRG) fabricated using a new dry-release poly-silicon MEMS technology. This single-wafer technology is capable of producing electrically isolated vertical electrodes as tall as the main body polysilicon structure (50 to 100’s urn tall) with various size air-gaps ranging from sub-micron to tens of microns. An open-loop sensitivity of 200pVldegfsec in a dynamic range of +250 degfsec was measured under low vacuum level for a prototype device tested in hybrid format. The resolution for a prototype sensor with a quality factor (Q) of 1200, drive amplitude of O.l5pm, and sense node parasitic capacitance of 2pF was measured to be less than 1 deg/sec in 1Hz bandwidth. Elimination of the parasitic capacitance and improvement in the quality factor of the ring structure will improve the resolution to 0.01 deg/sec in 1Hz bandwidth. Three hundred microns long clamped-clamped beam resonators fabricated in this technology have shown measured quality factors as high as 85,000 in 1mTorr vacuum.
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