Bulk-Si with poly bump process scheme for MEMS sensors

A MEMS process scheme designed for multi- sensors is presented. This new process scheme includes a poly bump not only provides stiction prevention and gap control function, and also electrical connection between MEMS structure and routing lines. Another advantage for this scheme is a better vacuum level because all material can be high temperature annealed before final encapsulation. This study also demonstrated some MEMS devices using this new scheme, including resonators, accelerometers and magnetometers.