Fabrication, characterization and efficiency analysis of a piezoelectric (AlN) ring micro-resonator on Si for low-power resonant converters

Piezoelectric microelectromechanical systems (MEMS) resonators on Si can be a potential candidate to replace discrete L-C components in series resonant converters. In this paper, ring shaped piezoelectric (AlN) micro-resonators on Si are reported. Having vibration in contour mode, these resonators can achieve resonant frequency as low as 87.28 MHz. Recently, we have fabricated high Q (>1000) piezoelectric resonator using a CMOS compatible fabrication process, and experimental characteristics of these devices are included in this paper. Contour mode AlN MEMS resonator with moderately low resonant frequency and motional resistance has been reported for the first time (the resonant frequency and motional resistance of the fabricated device is 87.28 MHz and 36.728 Ω respectively). Finally, an efficiency analysis of the series resonant topology has been performed using the equivalent electrical circuit model of the resonator.