Electrostatic Discharge and Cycling effects on Ohmic and capacitive RF-MEMS Switches

An extensive electrical characterization of radio frequency microelectromechanical systems (RF-MEMS) switches has been carried out to identify the dynamic response of both ohmic and capacitive devices, driven in different conditions of bias and actuation time. We have found that an optimum actuation voltage must be chosen as a tradeoff between good switch transmission and isolation properties and the need to avoid bouncing phenomena when the actuation voltage has been applied. Moreover, the degradation of shunt RF-MEMS strongly depends on the duty cycle of the actuation voltage waveform and, hence, on the time that the switch spends in the actuated state. We have also investigated the reliability to electrostatic discharge (ESD) events of the RF-MEMS switches. Using a transmission line pulser time domain reflectometer on wafer systems, we have stressed RF-MEMS switches in different conditions and found that the reliability of RF-MEMS devices could be heavily affected by ESD phenomena.