Design and FEM Analysis of Navigation Grade Low Noise and High Sensitivity Capacitive MEMS Accelerometer based on SOIMUMPs Process Constraints

Abstract

This paper presents the design of a single DoF capacitive MEMS accelerometer considering the commercially available microfabrication process constraints. The microfabrication process considered for the design optimization is SOIMUMPs process with silicon material and structural layer thickness of $25 \mu\mathrm{m}$ . The performance of the MEMS accelerometer is analyzed using both analytical and finite element method (FEM) based simulations. The proposed design offers high sensitivity, low noise, and resolution of 2 mg for an input acceleration range of ±50 g. The high mechanical and capacitance sensitivity is achieved by designing the symmetric suspension beams, utilizing the maximum area on the periphery of the proof mass and gap-antigap based differential capacitance sensing. The proposed design is ready for fabrication, with performance parameters that meet the requirement of its use in navigation grade defense applications.