Copper-based multimetal-contact RF MEMS switch

A novel multilayer stack Au/Cu/Au is proposed to increase the hardness of contact material of RF MEMS switch. The nanoindentation test results indicate that the hardness of Au/Cu/Au is 7 times higher than electroplated Au-film. The root-mean-square roughness of Au/Cu/Au is 13.7nm, while that of electroplated Au is 30.2nm. The pull-in voltage of the designed switch is 36.6V, the switch-on time is 39μs and the switch-off time is 8μs. The measured insertion loss is better than -0.5dB and the isolation is better than -25dB up to 20GHz.