MEMS technology for the fabrication of RF magnetic components

Microelectromechanical systems (MEMS) technology can be utilized for the fabrication of magnetic structures in multiple frequency ranges, ranging from low-megahertz metal-core devices for dc-dc converters to high-frequency dielectric or air core devices for RF application. These devices can also be fabricated in multiple locations: integral with silicon chips, in the interconnect layer between chip and board, and directly on the printed wiring board, in order to yield ultracompact magnetic microsystems. This paper describes examples of each of these fabrication approaches: high-frequency dielectric-core inductors for CMOS power amplifiers integrated on-chip, high-frequency air-core inductors fabricated within the interconnect layer between chip and board, and low-frequency metal-core inductors for dc-dc power conversion.