San Francisco, Calif.: French research and technology company CEA-Leti announced at Semicon West that its RF MEMS switch technology has reached a new level of maturity. The company says it has achieved a major advance in the reliability of the devices’ electrostatic actuators.
The switch design uses a dielectric-less solution in which an air gap prevents contact between the electrodes when the bridge is down, thanks to small dielectric dots placed under the mobile electrode. As a result, long-term tests show a drastic improvement in reliability. Also, no pull-down voltage drift has been observed during the tests.
Contact reliability has been improved by replacing the gold-based contacts that exhibited poor reliability and high sensitivity to stiction with better-performing ruthenium-based contacts. A hermetic thin-film packaging process also has been developed to prevent organic contamination and to maintain low contact resistance.
The switch-manufacturing process has been demonstrated on 200-mm silicon wafers at the MINATEC dedicated microelectromechanical-systems (MEMS) fabrication platform. Yields close to industrial standards have been achieved, providing thousands of working devices per wafer. Leti’s industrial partners are evaluating samples of these RF MEMS switches for use in efficient reflect-array antennas and redundancy switching matrices.