The advanced MEMS (aMEMS) process for fabricating wafer level vacuum packaged SOI-MEMS devices with embedded vertical feedthroughs

This paper presents a novel, inherently simple and low-cost fabrication and hermetic packaging method developed for SOI-MEMS devices, where an SOI wafer is used for the fabrication of MEMS structures as well as vertical feedthroughs, while a glass cap wafer is used for hermetic encapsulation and routing metallization. Glass-to-silicon anodically bonded seals yield a very stable cavity pressure of 150 mTorr after 15 days. The shear strength of the fabricated packages is above 7 MPa. Temperature cycling and ultra-high temperature shock tests results in no degradation in the hermeticity of the packaged chips.