Micromechanical resonators that have high performance and are small in size are competitive candidates for radio frequency (RF) device minimization, paving the way for high performance monolithic transceivers. A piezoelectric aluminium nitride radial-contour mode disc resonator with a CMOS-compatible fabrication process is presented. The piezoelectric properties of the resonator disc, concerning the driving voltage and resonance mode deformation, are analysed, revealing the advantages introduced when using a sputter deposited AlN thin film. The radial-contour resonance mode of the disc resonator was investigated by finite element method simulation and theoretical evaluation. The resonance frequency was found to be thickness-independent, which is beneficial for fabrication and integration. In view of CMOS compatibility, a fabrication process with a low thermal budget and a tungsten titanium sacrificial layer was designed; devices were fabricated on 4 inch silicon wafers. The RF performance of the resonators with a diameter of 150 μm was measured using a HP4395A network analyzer, yielding a resonant frequency of 14.11 MHz with a Q value of 3125 and a return loss of 31.46 dB. These results indicate that this device is attractive for use in RF frequency-selecting and generation devices in high performance wireless communication systems.
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