Piezoelectric aluminum nitride MEMS resonators for RF signal processing

The demand for highly-integrated analog filtering and frequency reference elements has spurred rapid innovation in the area of vibrating RF MEMS. To date, however, no single technology has emerged that can simultaneously deliver monolithic, post-CMOS integration of IF and RF components that can readily interface with 50 O electronic systems. AIN contour mode MEMS resonators have emerged a promising technology for enabling multi-frequency per silicon chip, CMOS-compatible, low-loss bandpass filters, but heretofore have been unable to reach GHz frequencies.;This dissertation introduces novel bandpass filter topologies based on monolithic and mechanically or acoustically coupled piezoelectric thin-film AIN contour mode plate resonators. The use of contour modes of vibration allows the filter center frequency to be determined arbitrarily at the mask layout level; the coupling techniques also enable the filter bandwidth to be engineered at the layout level. These filter topologies inherently offer good out-of-band rejection and can be cascaded electrically to realize hybrid networks with the desired filter shape factor.;A new bulk resonator topology has been developed that effectively uncouples the motional resistance and operating frequency of the device. The new design features selectively patterned interdigital transduction electrodes that selectively excite a specific higher-order contour mode of vibration in rectangular or annular AIN plates. The pitch of the electrodes determines the operating frequency of the device, while the length and number of electrodes determine the motional resistance. Higher-order contour mode AIN resonators have enabled the first lithography defined thin-film GHz electromechanical resonators.