RESONANT TRANSDUCER, MANUFACTURING METHOD THEREFOR, AND MULTI-LAYER STRUCTURE FOR RESONANT TRANSDUCER

A resonant transducer includes a silicon single crystal substrate, a silicon single crystal resonator disposed over the silicon single crystal substrate, a shell made of silicon, surrounding the resonator with gap, and forming a chamber together with the silicon single crystal substrate, an exciting module configured to excite the resonator, a vibration detecting module configured to detect vibration of the resonator, a first layer disposed over the chamber, the first layer having a through-hole, a second layer disposed over the first layer, a third layer covering the first layer and the second layer, and a projection extending from the second layer toward the resonator, the projection being spatially separated from the resonator, the projection, being separated from the first layer by a first gap, the second layer being separated from the first layer by a second gap, the first gap is communicated with the second gap.