Electrode materials, sputtering argon plasma

In contrast to argon plasma, in which the sputtering of metal from the electrode is the primary process, the deposition of polymeric materials via plasma polymerization predominantly takes place in methane plasma. In such a polymer-forming plasma, the sputter deposition of electrode materials is considered as a secondary process, and the extent of the sputtering of metal depends on the plasma polymerization conditions, the nature of the electrode material, and the magnetic field strength. 

The theoretical basis for sputtering has been known for a long time but more recently commercial methods have been developed along lines similar to those in vacuum evaporation just described. Essentially, a discharge of argon gas plasma is established between an anode and cathode electrode in this instance, the source material is the cathode, and the work piece the anode. Gas ions charged positively are attracted to the cathode, where they collide with it and remove atoms of the source material—which in turn travel to the anode and form a coating of sputtered material on the work piece. 

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