Piezoelectric micromechanical disk resonators towards UHF band

This paper presents the design, simulation, fabrication, and test results of a new type of piezoelectrically transduced micromechanical disk resonator approaching UHF frequencies. The resonators were fabricated from silicon-on-insulator (SOI) wafers with a 4-mask low-temperature process. The highest processing temperature was 250/spl deg/C, allowing post-CMOS integration compatibility. Several prototype resonators with measured diameter of 100 /spl mu/m and 60 /spl mu/m were tested in air, with the highest resonant peak observed at 208 MHz, which matched well with simulation results from finite-element analysis. A quality factor of 15 at 208 MHz was extracted, and is expected to be significantly higher with an optimized design and vacuum testing.