Patent attributes
Methods and apparatus for a magnetron assembly are provided herein. In some embodiments, a magnetron assembly includes a first base plate; a second base plate movable with respect to the first base plate between a first position and a second position; an outer magnetic pole in the shape of a loop and comprising an outer magnetic pole section coupled to the first base plate and an outer magnetic pole section coupled to the second base plate; and an inner magnetic pole disposed within the outer magnetic pole, wherein the outer and inner magnetic poles define a closed loop magnetic field, and wherein the closed loop magnetic field is maintained when the second base plate is disposed in both the first position and a second position.