RF MEMS Switches Supported by Polymeric Structures

RF MEMS shunt switches in coplanar waveguide (CPW) configuration have been designed, realized and tested for wideband isolation purposes. SU-8 negative photo-resist technology has been introduced for improving the bridge mechanics and the RF performances of the device. The polymeric material is used to elevate the ground planes of the CPW structure, with minor consequences on the electrical matching and an improvement in the bridge ends definition. The EM design has been followed by a sixstep photolithographic process on a 4" oxidized high resistivity silicon wafer, up to the release of the bridge by using a plasma etching technique.