Spatially resolved optical emission studies of fluorocarbon RF plasma through the use of UV-transmitting optical fibers

A technique for collecting spatially resolved optical emission from large rf plasma reactors is described. To demonstrate the sensitivity and versatility of this technique, emission within the quartz ultraviolet, 225–253 nm, was studied with particular emphasis on the “plasma dark space.” Spatial variations of CF2, AlF, and C atom emission were monitored. These results have been used for discussion and evaluation of various plasma excitation and reaction mechanisms involving atomic carbon in fluorocarbon plasmas.