PLASMA REACTOR WITH MINIMAL D.C. COILS FOR CUSP, SOLENOID AND MIRROR FIELDS FOR PLASMA UNIFORMITY AND DEVICE DAMAGE REDUCTION

摘要

A plasma reactor for processing a workpiece, includes a vacuum chamber 100 defined by a sidewall and ceiling, and a workpiece support pedestal 105 having a workpiece support surface in the chamber and facing the ceiling and including a cathode electrode. An RF power generator 40 is coupled to the cathode electrode. Plasma distribution is controlled by an external annular inner electromagnet 60 in a first plane overlying the workpiece support surface, an external annular outer electromagnet 65 in a second plane overlying the workpiece support surface and having a greater diameter than the inner electromagnet, and an external annular bottom electromagnet 401 in a third plane underlying the workpiece support surface. D.C. current supplies are connected to respective ones of the inner, outer and bottom electromagnets.