To provide a method for forming a Cu-contg. Al alloy wiring, etc., which suppresses the Cu residue, without needing new facilities and without adding complicated steps.

On the entire surface of an insulation film 1 a Ti type barrier film 3 having a barrier and adhesion properties, Al film 5 and Ti type antireflective film 7 are formed so as to form the Al film sandwiched between the Ti type films. A resist is applied and a wiring pattern is transfer thereto by the photolithography. Using the resist as a mask, the wiring films 3, 5, 7 are processed to form conductive wires 11. After peeling off the resist, the entire substrate surface is implanted with Cu ions 13 to introduce Cu in the conductive wires. The substrate is heat treated to thermally diffuse Cu in the conductive wires to form a Cu-contg.-Al wiring 21.