A novel method for fabricating MEMS three-axis accelerometers using low temperature Au-Sn eutectic bonding

Abstract

This paper presents a novel method for the fabrication of three-axis capacitive MEMS accelerometers by using low-temperature Au-Sn eutectic bonding that is applied to form a glass-silicon-glass multi-stack. The proposed method provides the implementation of individual in-plane and out-of-plane accelerometer elements in the same die using a glass-silicon-glass multi-stack structure formed at temperatures as low as 300°C while still ensuring the advantages of the previous approaches such as the voltage free bonding, inherent capping, and the differential sensing. The initial prototypes are verified to be functional and mechanically strong (>9.5MPa) by C-V measurements and shear strength tests. © 2016 IEEE.