Integrated MEMS LC Resonator with Sealed Air-Suspended Structure for Single-Chip RF LSIs

This paper describes an integrated MEMS LC resonator that consists of a MEMS inductor and varactor. The resonator features a sealed air-suspended structure: the inductor and varactor are suspended above a CMOS LSI to improve their performance, and they are sealed with a film to protect them during packaging. The quality factor of the inductor is four times higher than that of a CMOS top-layer-metal inductor, and the varactor has a tuning ratio of 100% at about 5-V applied voltage. The resonator is applied to a voltage- controlled oscillator to show its effectiveness for the development of single-chip RF LSIs.