Patent attributes
Methods and apparatus for processing a substrate are provided herein. For example, a method for processing a substrate comprises applying a DC target voltage to a target disposed within a processing volume of a plasma processing chamber, rotating a magnet disposed above the target at a default speed to direct sputter material from the target toward a substrate support disposed within the processing volume, measuring in-situ DC voltage in the processing volume, the in-situ DC voltage different from the DC target voltage, determining if a measured in-situ DC voltage is greater than a preset value, if the measured in-situ DC voltage is less than or equal to the preset value, maintaining the magnet at the default speed, and if the measured in-situ DC voltage is greater than the preset value, rotating the magnet at a speed less than the default speed to decrease the in-situ DC voltage.