Deposition of diamond-like carbon films on interior surface of long and slender quartz glass tube by enhanced glow discharge plasma immersion ion implantation

Diamond-like carbon (DLC) films are deposited on the interior surface of 100. mm long quartz glass tubes with inner diameters of 6, 4, and 0.9. mm by enhanced glow discharge plasma immersion ion implantation (EGD-PIII) at 10. kV. The acetylene plasma is generated inside the tube by electrons created in the plasma near the substrate and secondary electrons from ion bombardment. Acetylene gas pressure distribution obtained from finite element method shows that the pressure varies linearly from the inlet to the outlet of the tube. The electron mean free path, λ_e, and collision frequency, ν_e, are introduced to qualitatively explain the non-uniform DLC film thickness. Raman scattering indicates that the DLC films at different locations have a similar structure.