The present invention discloses a method including: providing a substrate; and sequentially stacking layers of two or more diamond-like carbon (DLC) films over the substrate to form a composite dielectric film, the composite dielectric film having a k value of about 1.5 or lower, the composite dielectric film having a Young's modulus of elasticity of about 25 GigaPascals or higher.The present invention further discloses a structure including: a substrate; a porous diamond-like carbon (DLC) film located over the substrate; an opening located in the porous DLC film; and a conductor located in the opening.