Piezoelectrically driven silicon carbide resonators

Silicon carbide cantilever beam resonators have been designed with top electrodes made of piezoelectric lead zirconium titanate (PZT). The devices have been simulated, fabricated, and tested. Piezoelectric actuation has been performed by applying an alternating actuation voltage to the PZT electrodes, thus inducing vertical displacements. The devices have been fabricated with a beam length of 150 and 200 μm, and driven into resonance at frequencies in the kilohertz range. The devices' resonance has been detected by monitoring the impedance of the actuating electrode. Simulations and measurements have shown that the electrode length on top of the beam influences the magnitude of the deflection and the resonant frequency of the devices. Furthermore, the electrical feedthrough capacitance presented by the piezoelectric electrode has been observed to strongly influence the output impedance of the resonators. The obtained results show the importance of the electrode design for the optimization of the performance and reliability of piezoelectrically driven resonators.