MEMS Sensor Drift Compensation with On-Chip Stress Sensing

Drift is a fundamental problem limiting MEMS gyroscope utilization in demanding navigation applications. In this paper, we present on-chip stress compensation results demonstrating that the drift can be eliminated. 16 capacitive stress sensors are tightly integrated with a ring gyroscope for stress compensation. A partial fitting algorithm results in a stability of 0.003°/h at two days of averaging time with no signs of drift. The stress sensitivity of the device is estimated as 0.1°/h/kPa. Packaging stress measurements with a stress array reveal nonuniformity and hysteresis. We also present an analytical modeling approach to model the effects of fabrication imperfections and stress. Analytical modeling can help on solving the challenging stress calibration problem.