Electrical feedthrough structures for micromachined devices and methods of fabricating the same

Abstract

Structures and methods are disclosed in conjunction with the fabrication of electrical lead transfer feedthroughs with respect to a sealed cavity. In some applications such as capacitive pressure sensing, the cavity may include an outer wall, in which case the electrically insulating barrier is preferably U-shaped, with the ends of the U terminating at the outer wall. The feedthrough section may alternatively take the form of an island of conductive material surrounded by the electrically insulating barrier, thus assuming an O-shape. The cavity may be evacuated or filled with specific gases at specific pressures. As such, the invention finds application in the packaging (vacuum or controlled environment) and production of a variety of transducers including but not limited to pressure sensors, flow sensors, optical devices (e.g., infrared detectors, ccd camera, and flat-panel displays) and resonating devices, such as gyroscopes, accelerometers, yaw sensors, telecommunication devices, etc. Multiple lead transfer feedthroughs may also be produced using this invention.