Simulation of Manufacturing Variations in a Z-axis CMOS-MEMS Gyroscope

摘要

This paper uses MEMS circuit-level simulation to correlate gyro performance measures such as zero rate output (ZRO), linear acceleration sensitivity (S_a) and cross-axis sensitivity (S_(ca)) to geometrical asymmetries. Elastic and electrostatic asymmetries in the gyroscope may arise due to device-level manufacturing variations in beam width, comb gap and metal mask misalignment in the CMOS-MEMS process. Analytical equations for the non-idealities are derived and compared with the simulation results. The analyses and simulations are used to develop pointers for robust design as well as manufacturing tolerances for limiting non-idealities.