Sputtering target materials

The sputtering process shown in Figure 19.1, utilizes the phenomena associated with a low-pressure gas discharge. The system comprises an anode and cathode generally the low-pressure chamber is earthed and forms an infinite area anode the small cathode surface is the target material from which gas ion-etching occurs, resulting in condensation of the material onto workpieces within the vacuum chamber. 

As the source of material (sputtering target) is a solid, a variety of electrode configurations can be used e.g., depositing material downward, upward or sideways. It is possible to electrically bias workpieces being coated. This can encourage a level of ion bombardment that can modify the surface and structure of a coating. 

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