Switched-Layer Design for SOI Bulk Micromachined XYZ Stage Using Stiction Bar for Interlayer Electrical Connection

A simple and new technique for interlayer electrical interconnection for silicon-on-insulator microelectromechanical systems (SOI-MEMS) micromachining was developed without using additional device layers or patterning processes. A part of the SOI microstructure was shaped into a slender cantilever and intentionally brought into contact onto the substrate surface by surface stiction force after sacrificial release. The contact resistance between the stiction bar and the substrate was studied with and without a subsequent metallization process. The stiction bar was found to improve the MEMS design flexibility in allocating electrical components (comb-drive electrodes and interconnection tethers) and mechanical components (suspensions and frame) to the SOI and the substrate layer and to make a high-density complex double-deck structure in a small footprint. As an example of the high-density design, we developed a micro-XYZ stage with the lateral and vertical comb-drive mechanisms and compared the design with the conventional bulk micromachined structures.