An apparatus and method for sensor architecture based on bulk machining of
Silicon-On-Oxide wafers and fusion bonding that provides a symmetric,
nearly all-silicon, hermetically sealed MEMS device having a sensor
mechanism formed in an active semiconductor layer, and opposing silicon
cover plates each having active layers bonded to opposite faces of the
sensor mechanism. The mechanism is structured with sensor mechanical
features structurally supported by at least one mechanism anchor. The
active layers of the cover plates each include interior features
structured to cooperate with the sensor mechanical features and an anchor
structured to cooperate with the mechanism anchor. A handle layer of each
cover plate includes a pit extending there through in alignment with the
cover plate anchor. An unbroken rim of dielectric material forms a seal
between the cover plate anchor and the pit and exposes an external
surface of the cover plate anchor.