Charging Effect in RF MEMS Switches with Dielectric Less Actuators

D. MARDIVIRIN, A. POTHIER, A. CRUNTEANU, P. BLONDY

XLIM UMR 6172–Université de Limoges/CNRS, 123 Avenue Albert Thomas, 87060 Limoges Cedex, France

Abstract. A major issue in the reliability of electrostatically actuated RF MEMS is dominated to dielectric charging troubles, since it generally induces a quick component failure. By using dielectric less actuator implemented on RF MEMS switches, it has been showed that this phenomenon is strongly attenuated. Also, the lifetime of the switch highly increases and charge trapping becomes residual. In this study, this actuator has been implemented on two kinds of RF MEMS switches: capacitive and ohmic contact. Based on experimental results, the actuator longterm reliability is presented and pull-down pull-up voltage drift behaviors are observed and modeled. Based on Curie–Von Schweidler equation, we demonstrate that the failure of these specific actuators can be predicted with a good accuracy. The projected lifetime of current RF-MEMS dielectric less switches held in the down state is expected to be several months or years, whereas the same switches held in the down state 50% of the time with a 10 Hz square bias voltage will have a lifetime of several tens of months or years.