Patent ID: 7378001

Claim:
A magnetron sputtering apparatus comprising: a target having a target surface at which the target is to be eroded; a vacuum chamber in which the target surface is exposed; a magnetron assembly for the target, the magnetron assembly including a magnet moveable relative to the target to produce uniform erosion of the target across the target surface; a support for holding a substrate onto which a film comprising material from the target is to be deposited; a closed loop magnet assembly including a coil whose loops are located outside the vacuum chamber and extend around the perimeter of the target, for magnetically containing or restricting a plasma adjacent to the target surface to alter the pattern of the erosion of the target produced by the magnetron assembly; and a control operatively connected to the magnet assembly and configured to control the magnet assembly to selectively cause the plasma to spread over substantially the entire target surface such that substantially the entire target surface may be eroded and cause the plasma to be confined adjacent to the target surface within an area smaller than that occupied by the plasma when the plasma is spread over substantially the entire target surface.