Nucleation of Carbonaceous Nanoparticles in a Low Pressure Ar/C2H2 Plasma with C2H4 Impurity

Computer simulations of one-dimensional multi-fluid equationsareused to study the effects of C2H4 addition onthe plasma chemistry and formation of nanoparticles in a capacitivelycoupled Ar/C2H2 plasma. The results indicatethat the most important effect is an enhanced production of hydrogen-richspecies, especially C4H4. Regarding the effectof C2H4 inlet on different routes of nanoparticlesnucleation, it was found that the nucleation via growth of neutralmolecules is significantly suppressed, while the radicals and anionsremain almost unaffected. As C2H4 participatesin many cationic reactions, the concentrations of hydrogen-rich cationsare largely enhanced, whereas those of carbon-rich cations are reduced.The numerical results also suggest that the main mechanism behindthe production of C6H6 is the insertion of theC(2)H(3) radical into C4H4. The concentrations of the precursors species of C6H6 are increased with an increase in the pressure but are reducedwith the applied RF voltage.