US Patent 7639105 Lithographically-defined multi-standard multi-frequency high-Q tunable micromechanical resonators

Disclosed are micromechanical resonator apparatus having features that permit multiple resonators on the same substrate to operate at different operating frequencies. Exemplary micromechanical resonator apparatus includes a support substrate and suspended micromechanical resonator apparatus having a resonance frequency. In one embodiment, the suspended micromechanical resonator apparatus comprises a device substrate that is suspended from and attached to the support substrate, a piezoelectric layer formed on the suspended device substrate, and a plurality of interdigitated upper electrodes formed on the piezoelectric layer. In another embodiment, the suspended micromechanical resonator apparatus comprises a device substrate that is suspended from and attached to the support substrate, a lower electrode formed on the suspended device substrate, a piezoelectric layer formed on the lower electrode, and a plurality of interdigitated upper electrodes formed on the piezoelectric layer. The substrate may comprise a silicon substrate, or a semiconductor-on-insulator substrate, such as a diamond on silicon substrate. Additionally, lateral frequency-adjusting electrodes may be disposed adjacent to the resonator apparatus that are separated therefrom by a capacitive gap, and which are configured to receive a direct current voltage that adjusts the resonance frequency of the resonator apparatus.