Lateral-field-excitation acoustic resonators for monolithic oscillators and filters

This paper describes a high-frequency acoustic resonator built on a low-stress silicon nitride cantilever for monolithic filters and oscillators at above 1 GHz. The unique features of our resonator include (1) usage of lateral electric field (rather than thickness-direction field) to excite bulk acoustic wave in piezoelectric ZnO film and (2) usage of surface micromachining to fabricate the resonator on silicon wafer. Our resonator is measured to have a resonant frequency of 531 MHz with Q of 738 and figure-of-merit of 207.