an icp a plasma reactor having an enclosure wherein at least part of the ceiling forms a dielectric window . a substrate support is positioned within the enclosure below the dielectric window . an rf power applicator is positioned above the dielectric window to radiate rf power through the dielectric window and into the enclosure . a plurality of gas injectors are distributed uniformly above the substrate support to supply processing gas into the enclosure . a circular baffle is situated inside the enclosure and positioned above the substrate support but below the plurality of gas injectors so as to redirect flow of the processing gas .