The bonding of LiNbO3-silicon via BCB material

Adhesive wafer bonding is a bonding approach using an intermediate layer for bonding (e.g. glass, polymers, resists, polyimides). This paper presents results on adhesive bonding using spin-on Benzocyclobutene(BCB) from Dow Chemicals. The advantages of using adhesive bonding for MEMS applications will be illustrated by presenting a technology of fabricating LiNbO₃-on-Si substrates. By changing the rotational speed of spin coating and BCB thickness, bonding temperature, hold temperature, bonding pressure, and other parameters, we carried out a series of process optimization experiment. Finally the bonding shear strength was tested. The results show that LiNbO₃ and silicon has a good bonding strength under the bonding conditions at 200°C. This process will allow us the hybrid integrated manufacturing of SAW devices.