A plasma reactor for physical vapor deposition (PVD), also known as sputtering, which is adapted so that the atomic species sputtered from the target can self-sustain the plasma without the need of a working gas such as argon. The self-sustained sputtering (SSS), which is particularly applicable to copper sputtering, is enabled by several means. The density of the plasma in the region of the magnet assembly of the magnetron is intensified for a fixed target power by reducing the size of the magnets. To provide more uniform sputtering, the small magnetron is scanned in one or two dimensions over the back of the target. The density of the plasma next to the target is also intensified by positioning an anode grid between the target and the substrate, which provides a more planar geometry. Additionally, the substrate can then be biased to more effectively control the energy and directionality of the flux of sputtered particles incident on the wafer.