Silicon MEMS Disk Resonator Gyroscope With an Integrated CMOS Analog Front-End

We present a 2-mm diameter, 35-mu m-thick disk resonator gyro (DRG) fabricated in < 111 > silicon with integrated 0.35-mu m CMOS analog front-end circuits. The device is fabricated in the commercial InvenSense Fabrication MEMS-CMOS integrated platform, which incorporates a wafer-level vacuum seal, yielding a quality factor (Q) of 2800 at the DRGs 78-kHz resonant frequency. After performing electrostatic tuning to enable mode-matched operation, this DRG achieves a 55 mu V/degrees/s sensitivity. Resonator vibration in the sense and drive axes is sensed using capacitive transduction, and amplified using a lownoise, on-chip integrated circuit. This allows the DRG to achieve Brownian noise-limited performance. The angle random walk is measured to be 0.008 degrees/s/root Hz and the bias instability is 20 degrees/h.