Low temperature wafer bonding of CMOS wafers

The continuous need for consumer electronics miniaturization requires not only size shrinking, but also higher degree of integration. The new demands imposed wafer bonding as an attractive technology for wafer-level integration. The resulting increased complexity of the devices brings new challenges to the processing techniques. In manufacturing processes wafer bonding can be used for integration of the electronic components (e.g. Complementary Metal-Oxide- Semiconductor - CMOS - circuitries) with the mechanical (e.g. resonators) or optical components (e.g. waveguides, mirrors) in a single, wafer-level process step. Wafer bonding using CMOS wafers brings additional challenges due to very strict specific requirements, particularly in terms of process temperature and contamination. These challenges were identified and wafer bonding process solutions will be presented illustrated with examples.