A creep-immune electrostatic actuator for RF-MEMS tunable capacitor

A high creep-immunity MEMS actuator is proposed for RF-MEMS tunable capacitor. The creep-immunity is attained using silicon nitride, SiN, for the spring portions, where the stress is concentrated. Compared with an aluminum spring, the creep-induced deformation is reduced by a factor of 23 at 100 °C. We also confirmed by a billion cycle test that the SiN spring does not develop a brittle fracture.