Structure design and processing of capacitive MEMS vibrating ring gyroscope

The MEMS vibrating ring gyroscope, which is based on four-antinode working principle, usually adopts high depth-to-width ratio structure to improve the capacitive value and SNR, which brings the Footing effect and makes the fabrication process more difficult. To solve this problem, a novel method is proposed which utilizes the Al metal layer attached under the silicon surface to restrain the footing effect. The fabrication results show that this method can effectively increase the processing precision of the structure. To verify the correctness of the designed structure, the frequency-sweeping testing on the structure manufactured is carried out, and based on this, the measurement and monitoring system is established. The static test is carried out, and the results show that the bias stability index of VRG sample is 101 (°)/h, which prove the feasibility of the design and the fabrication process.