Patent ID: 7879186

Claim:
A magnetic field generator for generating a magnetic field within a semiconductor substrate processing system comprising: a process chamber having a substrate support disposed therein, the substrate support having a support surface perpendicular to a central axis of the substrate support; a plurality of first coils disposed circumferentially about the process chamber and that form a first magnetic field having a convex shape proximate a substrate support surface of the substrate support; and a plurality of second coils disposed circumferentially about the process chamber and positioned proximate to the plurality of first coils, the plurality of second coils for providing a second magnetic field having a concave shape, where a combination of the first magnetic field and the second magnetic field form a magnetic field having a desired shape; wherein each coil of the plurality of first coils and the plurality of second coils have central axes that are substantially radially aligned with and perpendicular to the central axis of the substrate support.