The present invention is directed to a structure comprised of alternating
layers of
metal and sacrificial material built up using standard
CMOS processing techniques, a process for building such a structure, a process for fabricating devices from such a structure, and the devices fabricated from such a structure. In one embodiment, a first
metal layer is carried by a substrate. A first sacrificial layer is carried by the first
metal layer. A second metal layer is carried by the sacrificial layer. The second metal layer has a portion forming a micro-machined
metal mesh. When the portion of the first sacrificial layer in the area of the micro-machined
metal mesh is removed, the micro-machined
metal mesh is released and suspended above the first metal layer a height determined by the thickness of the first sacrificial layer. The structure may be varied by providing a base layer of sacrificial material between the surface of the substrate and the first metal layer. In that manner, a portion of the first metal layer may form a micro-machined mesh which is released when a portion of the base sacrificial layer in the area of the micro-machined mesh is removed. Additionally, a second layer of sacrificial material and a third metal layer may be provided. A micro-machined mesh may be formed in a portion of the third metal layer. The structure of the present invention may be used to construct variable capacitors, switches and, when certain of the meshes are sealed, microspeakers and microphones.