Abstract

This paper reports on the investigation of the main phenomenon which limits the lifetime of capacitive RF MEMS : dielectric charging. To understand this effect, we have developed specific test set which measures the electrical (at both low and microwave frequencies) and electromechanical performances of RF MEMS to investigate their reliability. Several experiments have thus been performed such as DC bias stress and cycling under different actuation waveforms and environment conditions. These tests have shown that the dielectric charging creates a drift of the threshold voltages and we propose an appropriate figure of merit regarding the lifetime of capacitive RF-MEMS and a key parameter to determine the type of the failure which occurs.