Methods and apparatus for a magnetron assembly are provided herein. In some embodiments, a magnetron assembly includes a shunt plate having a central axis and rotatable about the central axis, a closed loop magnetic pole coupled to a first surface of the shunt plate and disposed 360 degrees along a peripheral edge of the shunt plate, and an open loop magnetic pole coupled at a the first surface of the shunt plate wherein the open loop magnetic pole comprises two rows of magnets disposed about the central axis.