A single-mask process for fabricating enclosed, micron-scale subsurface cavities in a single crystal silicon substrate includes the steps of patterning the substrate to form vias, etching the cavities through the vias, and sealing the vias. Single cavities of any configuration may be produced, but a...http://www.google.com/patents/US6093330?utm_source=gb-gplus-sharePatent US6093330 - Microfabrication process for enclosed microstructures
