Patent ID: 8629517

Claim:
A device, comprising: a micro-electro-mechanical systems (MEMS) device including polysilicon electrodes adjacent a resonator element; one of a complementary metal-oxide semiconductor (CMOS) wafer or a carrier wafer fusion bonded to a first surface of the MEMS device; a capping wafer eutectically bonded to a second surface of the MEMS device, the resonator element sealed between the capping wafer and one of the CMOS wafer or the carrier wafer; and metal plugs disposed between respective polysilicon electrodes and a metal layer of the CMOS wafer to electrically couple the polysilicon electrodes to the metal layer of the CMOS wafer, wherein the metal plugs are shaped to have a first diameter in a portion proximate the metal layer and a second diameter that is wider than the first diameter in a portion proximate the polysilicon electrodes.