A Simplified Analytical Damping Constant Model for Perforated Proof Mass Structure of MEMS Capacitive Accelerometer by Multi-Layer Metal Technology

Abstract

This paper describes a simplified analytical model of a damping constant b to design a MEMS capacitive accelerometer by the multi-layer metal technology. The proposed model is introduced on the basis of combining the theoretical equation with the approximate form factor based on the measured data. In order to create the model, we fabricate several types of the MEMS capacitive accelerometers with the different structure parameters such as the etching hole area, the perforated proof mass area, and the gap. The calculation results show that the damping constant b by the proposed model is in accord with the measured b. Moreover, the Brownian noise BN calculated by the proposed model is also consistent with the measured BN. Therefore, it was confirmed that the proposed model will be effective for the analysis and the design of the MEMS capacitive accelerometer with the perforated proof mass.