Patent ID: 8330559

Claim:
A method, comprising: providing a substrate including a buried oxide layer and a top oxide layer; etching the substrate to form openings above the buried oxide layer and a micro-electro-mechanical systems (MEMS) resonator element between the openings, the MEMS resonator element enclosed within the buried oxide layer, the top oxide layer, and sidewall oxide layers; filling the openings with polysilicon to form polysilicon electrodes adjacent the MEMS resonator element; removing the top oxide layer and the sidewall oxide layers adjacent the MEMS resonator element; bonding the polysilicon electrodes to one of a complementary metal-oxide semiconductor (CMOS) wafer or a carrier wafer; removing the buried oxide layer adjacent the MEMS resonator element; and bonding the substrate to a capping wafer to seal the MEMS resonator element between the capping wafer and one of the CMOS wafer or the carrier wafer.