Abstract: A sputter coating system comprises a vacuum chamber, means for generating a vacuum in the vacuum chamber, a gas feed system attached to the vacuum chamber, a gas plasma forming system attached to the vacuum chamber, a system for confining and guiding a gas plasma within the vacuum chamber, and a prism-shaped sputter target assembly, with the material to be sputtered forming at least the outer surface of the target assembly and positioned such that the outer surface is surrounded by the plasma within the vacuum chamber. A negative polarity voltage is applied to the surface of the material such that sputtering occurs.