Large full scale, linearity and cross-axis rejection in low-power 3-axis gyroscopes based on nanoscale piezoresistors

Abstract

This work presents in-plane and out-of-plane Coriolis rate gyroscopes based on nano-scale piezoresistive readout and using an eutectic bonding between the bottom wafer, where the sensor is formed, and the cap wafer, where routing and metal pads are fabricated. The gyroscopes feature a novel design with a central levered sense frame, to maximize the device symmetry and compactness. The position of the piezoresistive nano-gauges along the lever system optimizes the scale-factor. Operation on a ± 3000 dps full-scale-range (FSR) demonstrates quite competitive performance, with a linearity error lower than 0.25% and a cross-axis rejection 50× better than state-of-the art consumer gyroscopes.