Selective metallization of silicon micromechanical devices

Abstract

A new wet process for selective copper deposition on silicon surfaces is employed to achieve conformal metallization of silicon micromechanical devices. The method is based on galvanic displacement of the metal from a fluoride-containing bath. The plating bath also comprises a complexing agent, a surfactant and an anti-stress additive. Surface passivation of the displaced Cu film is effected by dodecanethiol self assembled monolayer coating. This surface passivation is found effective in reducing adhesion of micro-electromechanical systems.