US Patent 7563509 Article with protective film

An article includes a substrate, a transition layer, and a diamond like carbon film. The transition layer is directly formed on a surface of the substrate. The diamond like carbon film is deposited on the transition layer, in contact therewith. The diamond like carbon film includes a nitrogen-doped diamond like carbon layer, a nitrogen-hydrogen doped diamond like carbon layer, and a hydrogen-doped diamond like carbon layer formed on the transition layer, in series. The nitrogen-doped diamond like carbon layer, in particular, is immediately adjacent the transition layer.