Effects of Fluorocarbon Films on CF Radical in CF4/H2 Plasma

The behavior of CF radicals in CF4/H2 plasma was studied as a function of the fluorocarbon film thickness grown on the inner wall in dc-pulsed CF4/H2 hollow cathode discharge plasma. Laser-induced fluorescence was used to examine the temporal behavior and radial distribution of the CF radical density. The thickness of the fluorocarbon films grown on the inner wall of the cylindrical hollow cathode was measured to investigate the influence of fluorocarbon film formation on the CF radical density in the plasma. For CF4/98%H2 discharge plasma, the radial distribution of the CF radical density deviated slightly from the zeroth-order Bessel function. The radial distribution of CF radical density changed to a uniform profile in CF4/98%H2 discharge plasma after exposure of the tube wall to CF4/20%H2 discharge.