Effect of substrate charging on the reliability of capacitive RF MEMS switches

In this paper, we show that substrate charging is another possible failure mechanism limiting the lifetime of capacitive RF MEMS switches. Switches fabricated on different substrates can exhibit a different lifetime. Also the influence of environmental conditions on the lifetime can depend on the type of substrate. In addition, we show that switches actuated with an actuation voltage below pull-in voltage can pull-in after some time due to charging of the substrate. We show results of experiments dedicated to emphasize this substrate charging by minimizing charging of the interposer dielectric.