Dielectric charging frequency response of MEMS switches with insulator-insulator contact

An extensive dielectric charging characterization is presented based on MEMS test structures with insulator-insulator contact. Surface charging by triboelectric effects has been the main mechanism that degrades the switch performance when both insulators are in contact. Surface charging not only changes by the applied electric field needed to close the switch, but also by the driving frequency. In this paper, we analyze and report the surface charging effects based on the applied electric field and cycling frequency. The results have shown a logarithmic time dependence of the surface charge generated at DC levels with a low pass filter characteristic at higher frequencies. Measurements show a cutoff frequency of approximately 100 Hz, so driving frequencies beyond 100 Hz will show a reduction of the amount of charge generated.