Dielectric Charging in Electrostatically Actuated MEMS Ohmic Switches

MEMS switches having separate signal and actuation electrodes with different air gaps are fabricated using a copper-based CMOS interconnect manufacturing process. By using a control voltage high enough to establish metal-metal contact between the signal electrodes while avoiding contact between the dielectric-covered actuation electrodes, dielectric charging appears to be tolerable. By simultaneously measuring the conductance across the signal electrodes and the capacitance across the actuation electrodes, the conductance-force characteristic can be readily monitored and analyzed. For the present switches, the effect of polarization charge appears to be negligible, and dielectric charging is significant only after dielectric contact is made and space charge is injected.