A bulk micromachined lateral axis gyroscope with vertical sensing comb capacitors

A bulk micromachined lateral axis single crystal silicon gyroscope with lateral driving comb electrodes and vertical differential sensing comb capacitors is designed, fabricated and tested. The neighboring electrodes of the newly designed sensing capacitors have a different thickness at the lower side, so the capacitors can differentially sense vertical motion and have low air damping. A bulk micromachining process, compatible with previously reported methods of accelerometer and z-axis gyroscope fabrication, is demonstrated. The fabricated gyroscope is tested in an atmospheric environment, and it has a sensitivity of 0.8 mV//spl deg//s, and a noise equivalent angular rate of 0.1/spl deg//s/Hz/sup 1/2 /.

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