Performance of molybdenum as a mechanical membrane for RF MEMS switches

This article details the construction and measurement of RF MEMS capacitive switches using molybdenum as the mechanical material. The resulting switches exhibit a significantly reduced rate of change in actuation voltage over temperature, with rates less than 0.03 V/degC up to 150degC. Resistivity of the molybdenum membranes averaged 10-11 muOmega-cm, yielding an effective shunt resistance of less than 0.25 Omega. Initial cycling measurements were made which show that the resulting membranes were capable of at least 20 billion cycles without failure, indicating that molybdenum is a promising mechanical material for constructing RF MEMS switches.