Novel Effa-Based Thin-Film RF-MEMS Technology

This paper presents applications of a novel electrostatic actuator using fringing fields as actuation mechanism, i.e. Electrostatic Fringing-Field Actuator or EFFA. The novel device is produced on an insulating substrate in a simple 2-mask process involving only one sacrificial layer and one metallisation. For the basic device, we report a non-deembedded capacitance ratio of 1:3 and a lifetime better than 10⁷ cycles with 40 V bipolar actuation at 100 Hz in N₂ atmosphere. The capacitance ratio and the C-V profile are tuned by modifying the technology and the design of the EFFA´s. We present a complete RF-MEMS technology using the EFFA´s as single actuators. We report for the first time on EFFA-based RF-circuits, e.g. phase shifter, as well as on tuneable parallel-plate capacitors and switches actuated by EFFA´s as relays, key elements to solve the problems of bias distributions throughout complex circuits.