Stiction in RFMEMS capacitive switches

Stiction is a major limiter in the reliability of RF MEMS capacitive switches and varactors. There are three major categories of stiction: temporary, voltage-independent, and permanent. The permanent stiction is defined in this paper as adhesion of two parts of otherwise separate surfaces even after exposure to water, high temperature anneals, a normal range of bias conditions or restoring forces, and after long periods of relaxation (>1 year). This paper will examine the effects of bias waveform, ambient, and moisture on permanent stiction in RF MEMS capacitive switches. The mitigation solutions for permanent stiction are often different than conventional wisdom for mitigation of temporary stiction.