A method for formation of a copper diffusion barrier film using aluminum is disclosed. In the method, thin aluminum (Al) film is deposited on a dielectric, and a surface of the deposited aluminum film is plasma treated with NH3, thereby transforming the surface of the plasma treated aluminum film into a nitride film basically composed of aluminum nitride (AlxNy), and an aluminum film is deposited on the surface of the transformed aluminum nitride film, and copper is deposited on the surface of the deposited aluminum film. Therefore, because the diffusion of copper is suppressed, the problem that leakages between metal lines increase as pitches between the metals decrease due to high integration of parts of semiconductor can be settled.