Background Sputtering is a method of depositing thin materials on a variety of substrates. Using radio frequency (RF) power to drive the deposition, both metals and dielectric materials can be grown.
The Sputter Coating ProcessIn sputtering, an inert gas is ionized in an electric field. These ions are driven into a target which in turn knocks off atoms of the source material. These atoms then coalesce onto the platen which contains the coated substrate.
Figure 1. A sputter coating machine.
ARC uses Sputter Tech, Perkin-Elmer and Alcatel-Comptech sputtering tools.
Sputter Coating ParametersSputtering parameters such as power, pressure, and gas constituents can be varied to match the stress of the sputtered film to that of the substrate. Deposition time is used to control film thickness.
Materials that can be SputteredMany materials can be sputtered, including metals like iron, cobalt, nickel, and chrome; precious metals such as platinum, gold, silver, and titanium. Dielectrics like silicon dioxide, alumina, and specialty glasses can also be sputtered.
Film ThicknessesFilm thickness can vary from a few angstroms of a GMR pinning layer, to dozens of microns as in alumina base and overcoats for thin film recording heads. Computer controlled deposition machines ensure repeatable results.