RF MEMS switches with sic microbridges for improved reliability

RF MEMS switches which utilize an insulating SiC microbridge as a structural layer have been developed. The MEMS switch with the 500 nm SiC microbridge exhibits good off-state performance but poor on-state characteristics due to the small on-state capacitance of the structure. However the mechanical reliability of the switch is exceptional. The MEMS switch with the 300 nm SiC thick microbridge has outstanding down position (on-state) RF characteristics which is do to the film being 40% thinner then the 500 nm microbridge thus creating a much larger on-state capacitance. Unfortunately the 300 nm thick microbridge does not actuate readily. It is believed that this is due to the stresses within the bridge.