ELECTROSTATIC FRINGING-FIELD ACTUATOR (EFFA): APPLICATION towards A Low-Complexity RF-MEMS technology

摘要

This paper presents a novel electrostatic actuator using fringing fields as actuation mechanism, ie 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. As a proof of concept, we produced and characterized EFFA-based tuneable RF devices and circuits in various technological implementations of remarkable simplicity. This simplicity allows a vast flexibility for the processing and as a result strongly eases the integration of the EFFA's into existing technologies. We report a non-deembedded measured capacitance ratio of 1:3 and a lifetime of more than 10{sup}7 cycles with 40V bipolar actuation at 100Hz in N{sub}2 atmosphere. Both the capacitance ratio and the C-V profile were tuned by modifying the technology, e.g. coating the substrate before processing the EFFA's, and the design, e.g. switching from clamped-free to clamped-clamped devices. Finally, note that the fringing-field actuation principle we demonstrated by means of RF-MEMS components can be used also as an electrostatic sensing mechanism.