Electromechanical resonances of SiC and AlN beams under ambient conditions

MEMS resonators offer great potential for RF sensor and filter applications. A semiconductor process has been used to prepare SiC and AlN beam resonators. The metallised beams are excited by an RF current in a permanent magnetic field. The resonant response is detected by the induced voltage. Despite the weakness of the signal, accurate detection has been achieved in the time domain, under ambient conditions in a magnetic field of about 0.5 T. The resonant response bears valuable information on the structural quality of the material and identifies potential for further improvement. The time domain technique presents an elegant approach to sensing applications.