In one embodiment, a magnetron assembly comprises a plurality of magnets and a yoke configured to hold the plurality of magnets in at least four independent linear arrays. The plurality of magnets is arranged in the yoke so as to form a pattern comprising an outer portion and an inner portion. The outer portion substantially surrounds the perimeter of the inner portion. The magnets used to form the outer portion have a first polarity and the magnets used to form the inner portion having a second polarity. The outer portion of the pattern comprises a pair of elongated sections that are substantially parallel to one another. The outer portion of the pattern comprises a pair of turnaround sections, wherein each turnaround section substantially spans respective ends of the pair of elongated sections and wherein each turnaround section comprises a plurality of magnets having the first polarity. Other embodiments are described.
