A dual-position magnetron that is rotated about a central axis in back of a sputtering target, particularly for sputtering an edge of a target of a barrier material onto a wafer and cleaning material redeposited at a center of the target. During target cleaning, wafer bias is reduced. In one embodiment, an arc-shaped magnetron is supported on a pivot arm pivoting on the end of a bracket fixed to the rotary shaft. A spring biases the pivot arm such that the magnetron is urged towards and overlies the target center. Centrifugal force at increased rotation rate overcomes the spring bias and shift the magnetron to an outer position with the long magnetron dimension aligned with the target edge. Mechanical stops prevent excessive movement in either direction. Other mechanisms include linear slides and actuators.