A method for fabricating a semiconductor device includes the steps of (a) forming a plasma of a gas having carbon and fluorine, and forming an internal insulation film provided with a fluorine-doped carbon film formed on a substrate using the plasma; (b) forming a metal film on the internal insulation film; (c) etching the metal film according to a pattern to form a hard mask; (d) forming a concave part in the fluorine-doped carbon film by etching the fluorine-doped carbon film using the hard mask; (e) forming a film formation of a wiring material on the substrate for filling the concave part with the wiring material; (f) removing an excess part of the wiring material and the hard mask on the fluorine-doped carbon film for exposing a surface of the fluorine-doped carbon film; and (g) removing an oxide formed on the surface of the fluorine-doped film.