Identifying degradation mechanisms in RF MEMS capacitive switches

In this paper we demonstrate how different degradation mechanisms of RF MEMS capacitive switches can be identified by carefully examining changes in key aspects of the measured C-V curves. We show that C-V curve narrowing can occur either due to mechanical deformation or to laterally inhomogeneous dielectric charging. We also show how these two degradation mechanisms can be distinguished by monitoring the change in the pull-in and pull-out voltages. Our measurements indicate that both degradation mechanisms do indeed occur in practice, depending on the stress conditions.