Optimization of pulse reversal electrodeposition with fine grains and low roughness for GaAs RF MEMS structures

GaAs MESFET-based switches suffer from high insertion losses. As an alternative, GaAs RF MEMS have shown great promise due to high isolation, low insertion losses, and wide bandwidths. Some factors constraining the fabrication have been suitable planarization techniques, quality of metallisation, stress in the beams, and elimination of stiction of beams to the central signal electrode. Quality of metallisation makes pulse reversal plating technique viable for production compared to DC plating. Coplanar waveguide pads, anchors, and beams are formed using this process. This paper discusses the optimization of pulse reversal electrodeposition process to fabricate different stages of RF MEMS switches.