Differential internal dielectric transduction of a Lame-mode resonator

This paper reports the parallel internal electrostatic transduction of a laterally driven Lame-mode polysilicon resonator. The transducer is fabricated using a manufacturable double nanogap process, where the 50 nm silicon nitride dielectric layers are formed on sidewalls of an optically defined trench by a conformal deposition, which is followed by refilling the trench with a doped polysilicon electrode layer. The transduction electrodes are placed and oriented to maximize electromechanical transduction efficiency for the fundamental Lame mode. A 128.15 MHz Lame-mode resonator is driven and sensed differentially, resulting in a motional resistance of 30 k Omega and the quality factor of Q > 12 000 in air.