Single crystal silicon cantilever-based RF-MEMS switches using surface processing on SOI

This paper describes a novel structure and simple fabrication process for low-loss, low-cost, and high-yield RF-MEMS switches. Our switch has a single crystal silicon (SCS) cantilever, above which are located electroplated bridge electrodes on silicon-on-insulator (SOI) substrates. The fabrication process does not require any complex processes, such as wafer transfer, wafer backside etching, special planarization techniques, or low-stress thin-film formation. The fabricated series switch features a low-loss performance and small size. The overall insertion loss is -0.1 dB and the isolation is -30 dB at 5GHz. The size of the SP4T switch is 1.4 × 0.9 mm².