An isolation process which enhances the performance of silicon
micromechanical devices incorporates dielectric isolation segments within
the silicon microstructure, which is otherwise composed of an
interconnected grid of cantilevered beams. A metal layer on top of the
beams provides interconnects and also allows contact to the silicon beams,
electrically activating the device for motion or transduction. Multiple
conduction paths are incorporated through a metal patterning step prior to
structure definition. The invention improves manufacturability of previous
processes by performing all lithographic patterning steps on flat
topographies, and removing complicated metal sputtering steps required of
most high aspect ratio processes. With little modification, the invention
can be implemented with in grated circuit fabrication sequences for fully
integrated devices.