High Q factor RF MEMS Tunable Metallic Parallel Plate Capacitor

This paper reports the fabrication and electrical characterization of a MEMS metallic tunable capacitor to be used as voltage controlled device in tuning telecommunication circuits. A novel fabrication process to obtain parallel plate metallic capacitors based on deep reactive ion etching (DRIE) bulk micromachining techniques have been developed. Devices of three different electrode areas have been fabricated and the influence of the area in the main characteristics of the MEMS capacitors has been established. The interaction of the DC tuning voltage and AC signal and their influence on the tuning behavior has been analyzed and the top limits have been estimated. This fabrication process already had been used to develop zipper actuation capacitors but not to fabricate parallel plate actuation capacitors. The obtained results make this kind of MEMS tunable metallic capacitors appropriate candidates for its use in the new power MEMS scenario.