Si-gold-glass hybrid wafer bond for 3D-MEMS and wafer level packaging

We report a relatively low temperature (<400 °C) hybrid wafer bonding process that results in the simultaneous anodic and eutectic bonding in different predetermined regions of the wafer. This hybrid bonding process has potential applications in CMOS-MEMS device integration and wafer level packaging. We demonstrate the process by realizing a simple MEMS cantilever beam and a complex MEMS gyroscope structure. These structures are characterized for ohmic contact and electromechanical response to verify the electrical interconnect and the mechanical strength of the structure at the bond interface.