Batch processing of laterally mobile structures in single-crystalline silicon

Abstract The introduction of elements free to move in the lateral wafer directions may have a great impact on the evolution of silicon micromechanics. Such laterally mobile structures allowing rotation and sliding motion can be used in sensor and actuator applications that have been inaccessible so far due to performance or cost limitations of present technology. This paper deals with the possibility of making these structures in single-crystalline silicon and outlines some fabrication processes using lamination of two oxidized wafers to form a sacrificial layer that will attach the mobile structure to the substrate, and a lamination of silicon surfaces to attach the overlay to the substrate. Both the mobile structure and the overlay will then have anisotropic properties, which gives new possibilities when designing three-dimensional mobile structures.