Metallic wiring board and a method for producing the same

Abstract

The method for producing a metallic wiring board of this invention comprises the steps of: implanting nitrogen on a surface of a substrate; forming a metallic film including, as a main component, one of Ta and Nb on the surface of the substrate where nitrogen is implanted by a sputtering method to form a metallic wiring by patterning the metallic film; and forming an insulating film by anodic oxidation of a surface of the metallic wiring. In the step of forming a metallic wiring form Ta or Nb on a substrate or a protective layer including nitrogen to anodic-oxidize the surface of the metallic wiring, Ta ions or Nb ions do not enter the substrate. Further, the substrate or a protective layer is doped with nitrogen, and a Ta layer is formed by the sputtering method thereon. The sputtering method has a characteristic that a material contained in the substrate is mixed into a film formed in the initial stage of the coating. Therefore, the doped nitrogen enters the Ta film, and a thin .alpha.-Ta layer is formed on the substrate or the protective film. The Ta layer to be epitaxially grown thereon is an .alpha.-Ta layer including no impurity. Thus, a Ta layer with a specific resistance of about 25 .mu..OMEGA.cm is obtained.