Synchrotron radiation for microstructure fabrication

Most of the presently known microstructures are still fabricated using silicon-based technologies. However, in the case of fabrication using anisotropic etching, geometrical limitations due to the crystallographic nature of silicon prevent the design of any in-place structure shapes. If microsystems, built by means of reactive ion etching and sacrificial layer technology do have freedom for lateral geometry, they are limited to a few micrometers height only. Nevertheless, and in spite of difficulties to always answer the demands in the best way, real microsystems are produced by these techniques and are currently present on the market. To overpass these limitations, other technologies have been studied and developed in recent years. Among them the LIGA process (German acronym for Lithography, Electroplating, Molding), which uses synchrotron radiation and in particular its hard X-Ray spectrum, is certainly the most promising one regarding to, very high aspect ratio, submicron precision, arbitrary pattering and mass production capabilities. Furthermore, LIGA can handle a large variety of materials to fabricate microsystems.