Novel chemistry for surface engineering in MEMS

It is well recognized that controlling surface forces is one of the key issues in the design, fabrication, and operation of microelectromechanical systems (MEMS). In this report we present a novel strategy for the efficient assembly of organic monolayers onto silicon surfaces to control surface energy. This is achieved by the reaction between an alcohol functional group and a chlorinated Si surface. The resulting molecular monolayers are thermally and chemically stable. Surface adhesion energy on silicon is reduced by a factor of 40 by the monolayer coating and friction coefficient of the coated surface is only 0.013. The coatings are successfully demonstrated in adhesion reduction in a model MEMS structure: cantilever beam array (CBA). Polycrystalline beams with length up to 1.5 mm can be released.