Single-chip multiple-frequency VHF low-impedance micro piezoelectric resonators

This letter reports on the design, fabrication, and testing a new class of low-impedance multiple-frequency micromechanical resonator using piezoelectric transduction mechanism. The resonator is fabricated out of a 3-μm-thick silicon layer on a silicon-on-insulator wafer with a low-temperature post-CMOS compatible process. Two types of low-impedance resonators using the same design principle are presented here. The center frequency of the novel resonator is set by the lithographically defined in-plane dimension of the device (width of bar or radius of disk). The 200-μm-diameter disk-shaped resonator is measured to have an impedance of 1.6 k/spl Omega/ at the resonant frequency of 45.4 MHz, with a quality factor of 1100. The bar-type resonator is measured to have an impedance of 920 /spl Omega/ at 60 MHz, exhibiting a Q factor of 1400.