Comparison of AuNi5 films deposited by laser ablation and sputtering for RF MEMS switch contacts

AuNi5 films, commonly deposited by sputtering and evaporation, are used in microswitches as an alternative to Au contacts for their smaller contact adhesion. In this work, we investigate whether Pulsed Laser Deposition (PLD) is suitable for the deposition of RF MEMS switch contact materials by comparing the properties and performance of AuNi5 films produced by PLD to films of similar thickness deposited by sputtering. We compare films' chemical composition, microstructure, stress, hardness and contact force versus contact resistance characteristics using films of different physical properties. We concluded that for PLD films to be used as switch contacts, they need to have as small particulate density as possible to provide reliable performance, which indicates reproducibility of experimental results when using equipment with the same settings on contact films deposited at the same conditions.