Nanoscale characterization of different stiction mechanisms in electrostatic RF-MEMS switches

In electrostatic capacitive MEMS switches, stiction can be caused by two main mechanisms: dielectric charging and meniscus formation resulting from the adsorbed water film between the switch suspended electrode and the dielectric film. In this study, for the first time the influence of each mechanism and the interaction between both mechanisms were investigated by measuring the adhesive force under different electrical stress conditions and relative humidity levels. An atomic force microscope (AFM) was used to perform force-distance curve measurements on the nanoscale. The investigation reveals an in-depth understanding of different stiction mechanisms, and provides accurate explanations for the literature reported device level measurements for MEMS switches.