A single-crystal silicon gyroscope with decoupled drive and sense

We present preliminary results for a single-crystal silicon gyroscope with decoupled drive and sense oscillators. The gyroscope is fabricated using a plasma micromachining process on a six-inch MEMS production line at Kionix, Inc. The process yields high-aspect-ratio structures, large structure-to-substrate separation, and low-parasitic electrodes, unlike designs that rely on silicon-on-insulator substrates, polysilicon, or thick epitaxial layers. We describe the fabrication process and emphasize the design, operation, and testing of the sensor. Results to date have yielded resolutions of 0.15 deg/sec over a 100Hz bandwidth, short term bias stabilities < 100 deg/hr, and quadrature signals < 25 deg/sec.