Wafer Bonding with nanoprecision alignment for micro/nano systems

Exploiting mechanical principles of kinematic and elastic averaging, a novel passive approach has been developed to achieve nanoprecision bonding alignment. Alignment features comprising cantilever supported pyramids and V-pits have been designed and fabricated at silicon chip level. The engagement between the pyramids and pits and the compliance of the cantilevers result in the passive alignment. Infrared (IR) and scanning electron microscopy (SEM) inspections repeatedly confirmed the alignment accuracy of better than 200 nm at the bonding interface with good bonding quality. The applicability of the developed alignment technique and future works towards wafer level applications for advanced micro/nano systems are discussed.