Finite-Volume Method for Creep Analysis of Thin RF MEMS Devices Using the Theory of Plates

Creep is a critical physical mechanism responsible for the failure of radio-frequency (RF) capacitive micro-electro-mechanical systems (MEMS) switches, especially those operating at high RF power. Accurate modeling of creep in RF MEMS metallic membranes is necessary to estimate device lifetime and to improve their reliability. Moreover, the devices are frequently very thin, with aspect ratios as high as 1: 500, and conventional three-dimensional structural modeling is onerous and unnecessary. In this article we extend a cell-centered finite-volume approach, previously developed to model thin membranes using Mindlin-Reissner plate theory, to study creep in RF MEMS devices. Results show that the present methodology can accurately predict the long-term creep behavior in thin RF MEMS devices in a computationally efficient manner.