Amorphous SiC as a structural layer in microbridge-based RF MEMS switches for use in software-defined radio

SiC is an attractive material for MEMS due to its outstanding mechanical, chemical and electrical properties. Crystalline SiC films are typically deposited at temperatures > 900degC, however amorphous SiC (a-SiC) films are deposited at temperatures below 400degC by PECVD [1], thus enabling deposition on temperature-sensitive substrates, such as those incorporating buried metal electrode structures. For RF MEMS switch applications, SiC is particularly attractive for its chemical inertness, anti-stiction properties and mechanical stiffness. NASA expects to replace multiple receiver-based communications architectures with a single, software-defined radio (SDR). RF MEMS switches have the potential to add configurability and improved RF performance to SDR systems while reducing system complexity, size, and weight. The purpose of this study was to explore the use of a-SiC as a structural material in RF MEMS switches.