Ion Composition Of Rf Ccp In Ar/H-2 Mixtures

The ion composition of Ar/H-2 plasmas along with the fluxes and energies of the certain ion sort are of great interest for various applications. In this paper the question of the main reactions which contribute most to the ion composition is being studied in an asymmetric dual-frequency rf CCP discharge with an applied rf-bias. A combination of experiment with a numerical scheme developed on the base of the particle-in-cell model with Monte-Carlo collisions is applied. The mass-spectrometer is used for measuring the ion composition at the discharge chamber wall, while the ion composition on the surface of an rf-biased electrode is estimated from the retarded field energy analyzer measurements to establish the role of the sheath processes in the ion composition. It is shown that the main ions are H-3(+), Ar+ and ArH+ but their relative concentrations strongly depend on the initial H-2 content in the mixture. The processes in the bulk plasma are revealed to be determinative for the ion composition whereas the sheath processes do not have a significant effect under the conditions considered.