Micromechanical voltage controlled switches and circuits

Micromechanical devices and circuits have been fabricated in which a thin (3500 Å) metal-coated SiO2membrane, ∼76 µm long, is suspended over a 7 µm deep well anisotropically etched in oriented crystalline silicon. Additional raised structures formed by gold plating are attached to the membrane such that an electrical switching function is accomplished when the membrane is electrostatically deflected downward into the well. Switching times of less than 40 µsec have been observed at deflection voltages of about 60 V in this preliminary design The very high off/on state impedance ratios of these devices suggest applications in the areas of analog signal switching and charge storage related to optical image storage. Fabrication and operation of these devices and circuits are described, and more complex implementations of this new technology are discussed.