Abstract: An apparatus for sputtering target material onto a substrate based on a plasma confining racetrack having two parallel straight portions and two turnaround portions includes a tubular target, an elongated magnet array, and a drive mechanism. The tubular target has two ends in proximity to the two turnaround portions and a longitudinal axis about which the target is rotatable. The magnet array is supported within the target to generate a plasma-confining magnetic field. The array includes a central stationary portion of magnets and two axially movable shunts positioned at the ends of the stationary portion. Each shunt carries a magnet segment configured to slidably extend from each end of the stationary portion to define a gap. The gaps are positioned internal to the turnaround portions. The drive mechanism axially moves the shunts parallel to the longitudinal axis of the target to vary a width of the gaps.

Abstract: An apparatus for sputtering target material onto a substrate based on a plasma confining racetrack having two parallel straight portions and two turnaround portions includes a tubular target, an elongated magnet array, and a drive mechanism. The tubular target has two ends in proximity to the two turnaround portions and a longitudinal axis about which the target is rotatable. The magnet array is supported within the target to generate a plasma-confining magnetic field. The array includes a central stationary portion of magnets and two axially movable shunts positioned at the ends of the stationary portion. Each shunt carries a magnet segment configured to slidably extend from each end of the stationary portion to define a gap. The gaps are positioned internal to the turnaround portions. The drive mechanism axially moves the shunts parallel to the longitudinal axis of the target to vary a width of the gaps.