A method for fabrication of single crystal silicon micromechanical
resonators using a two-wafer process, including either a
Silicon-on-insulator (SOI) or insulating base and resonator wafers,
wherein resonator anchors, a capacitive air gap, isolation trenches, and
alignment marks are micromachined in an active layer of the base wafer;
the active layer of the resonator wafer is bonded directly to the active
layer of the base wafer; the handle and dielectric layers of the
resonator wafer are removed; viewing windows are opened in the active
layer of the resonator wafer; masking the single crystal silicon
semiconductor material active layer of the resonator wafer with
photoresist material; a single crystal silicon resonator is machined in
the active layer of the resonator wafer using silicon dry etch
micromachining technology; and the photoresist material is subsequently
dry stripped.