I-shaped thermally actuated VHF resonators with submicron components

Thermally actuated piezoresistive readout single crystal silicon (SCS) resonators with a device footprint of ∼110 μm2 have been experimentally demonstrated at operating frequencies of 112–176 MHz. An SOIMEMS fabrication process was developed which incorporates electron beam lithography to achieve submicron dimensions. Demonstrated performance under vacuum (50–70 Torr) includes a Q = 5750 and motional conductance of 89.6 μA/V. Frequency tunability of 2.1% in ambient and 3.66% under vacuum is achieved by variation of the DC bias current. The effects of asymmetry of the devices on operating frequency due to fabrication imperfections are considered qualitatively using commercial modeling software.