Plasma reactor with multiple small internal inductive antennas

Abstract

The present invention employs a plurality of small inductive antennas to generate a processing plasma. In one embodiment, small coil antennas are secured within the chamber so that both of the pole regions of the antennas couple power to the plasma. The antennas may be oriented so that poles regions are anywhere from perpendicular, to parallel to a chamber wall. The number, location, and orientation of the small antennas within the chamber may be selected to optimize plasma characteristics. In addition, the antennas may be secured to top, side, or bottom walls to improve plasma characteristics; and power deposition within the processing chamber may be adjusted by changing the orientation of the coils, and the magnitude and phase relationship of RF power through the individual antennas. Process gas may be selectively delivered to areas of high power deposition such as adjacent pole regions or through the center of a coil or loop antenna to control plasma characteristics. In a preferred embodiment, the antennas are formed of a conductor surrounded by a non-sputtering, electrically insulating, thermally conductive jacket coupled to an electrically conductive chamber wall. The exposed surface of the jacket may be segmented to reduce eddy currents in conductive deposits.