Patent ID: 8445304

Claim:
A method of fabricating a MEMS device comprising the steps of: (a) growing or depositing an insulation layer on a top surface and a bottom surface of an engineered substrate comprising an upper and a lower layer of a semiconductor, sandwiching a central dielectric layer therebetween; (b) etching the lower semiconductor layer, thereby creating at least one via through the lower semiconductor layer and exposing the central dielectric layer; (c) lining the at least one via with an insulator; (d) etching the central dielectric layer exposed through the via, to expose the upper semiconductor layer through the at least one via; (e) filling the via with a conductive material; (f) forming a MEMS cavity in the upper semiconductor layer by etching the upper surface of the upper semiconductor layer; (h) bonding a third semiconductor layer to the upper semiconductor layer; (j) etching the third semiconductor layer to form the MEMS device; and (j) capping the MEMS cavity with a semiconductor cap hermetically sealed to the third semiconductor layer.