The invention is embodied in an RF plasma reactor for processing a semiconductor workpiece, including wall structures for containing a plasma therein, a workpiece support, a coil antenna capable of receiving a source RF power signal and being juxtaposed near the chamber, the workpiece support including a bias electrode capable of receiving a bias RF power signal, and first and second magnet structures adjacent the wall structure and in spaced relationship, with one pole of the first magnet structure facing an opposite pole of the second magnet structure, the magnet structures providing a plasma-confining static magnetic field adjacent said wall structure. The invention is also embodied in an RF plasma reactor for processing a semiconductor workpiece, including one or more wall structures for containing a plasma therein, a workpiece support, the workpiece support comprising a lower electrode, an upper electrode facing the lower electrode and spaced across a plasma generation region of said chamber from said lower electrode, and first and second magnet structures adjacent the wall structure and in spaced relationship with one pole of the first magnet structure facing an opposite pole of the second magnet structure, the magnet structures providing a plasma-confining static magnetic field adjacent said wall structure.