A plasma deposition apparatus includes a first plasma source that can produce a plasma confined in a magnetic field. The first plasma source includes a closed-loop electrode defining a center region therein and a central axis through the central region, and one or more magnets that are outside an inner surface of the closed-loop electrode. The magnets can produce a magnetic field in the center region. The one or more magnets can be at least partially embedded in the closed-loop electrode. The closed-loop electrode and the magnets can produce a plasma of ions to sputter atoms off a sputtering target or a backing plate.