Electrical control of plasma spatial uniformity investigated by planar laser-induced fluorescence

Planar laser-induced fluorescence was performed in the parallel-plate gaseous electronics conference reference cell to determine two-dimensional maps of the CF/sub 2/ radical in 89% CF/sub 4//11% O/sub 2/ chamber-cleaning plasmas. The spatial characteristics of the CF/sub 2/ density and of broadband optical emission were controlled by varying the current at the upper electrode by adjusting the impedance between the upper electrode and ground. The results suggest that electrical control of the current paths through the plasma could be used to control the spatial distribution of reactive chemical species, aiding in the optimization of chamber-cleaning plasmas.