Process apparatus and method for improving plasma production of an inductively coupled plasma

A processing system for processing a substrate with a plasma, comprising:

• a processing chamber defining a processing space for containing a substrate to be processed with a plasma formed within the processing chamber;
• a planar dielectric window interfacing with the processing chamber proximate to the processing space;
• a core element formed of a material having a high magnetic permeability in comparison with air, the core element positioned outside of the processing chamber and proximate to the dielectric window and having an axis aligned generally parallel to the dielectric window, and the core element including a first surface facing toward the processing space, a second surface facing away from the processing space, and a channel defined in at least the second surface;
• and
• an antenna positioned outside of the processing chamber, the antenna including a plurality of coil turns wound circumferentially about the axis of the core element, at least one of said coil turns including a segment positioned in the channel and separated from the planar dielectric window by the core element, and the antenna, when electrical current is conducted thereby, operative to generate a magnetic flux directed by the core element into the processing space through the dielectric window for forming the plasma in the processing space.