Effects of CF₄ content on particle densities and reaction pathways in atmospheric-pressure Ar/CF₄ pulsed dielectric barrier discharge plasma

Abstract

Ar/CF4 discharge plasma etching is a promising approach to achieving a high etch rate and anisotropic etching. A 1D fluid model is established to numerically study the effects of CF4 content on particle densities and reaction pathways in Ar/CF4 pulsed dielectric barrier discharge plasma at atmospheric pressure. The simulation results indicate that, with increasing CF4 content, Ar+ densities decrease but the densities of other positive ions increase, and the electron densities do not undergo a dramatic change but the densities present an approximately linear increase. The densities of CF3 and F reach their maximums when the CF4 content is 70%. In Ar, the electron impacts with Ar are the essential reaction pathways to generate Ar+, Arm, and Ar*. In CF4, the electron impacts with CF4 are the main paths to produce , , CF+, F+, , CF2, F2, , F−, CF3, and F. Besides, → + F and + F → CF3 + F− produce part of and F−. Decomposition, recombination, and charge exchange reactions all contribute to the generation of CF3 and F. In the Ar/CF4 mixture, Ar + → CF3 + Ar+ and CF4 + Ar+ → + F + Ar produce a great deal of Ar+, , CF3, and F. The contribution ratios of the reactions CF4 + e → CF3 + F+ + 2e and F− + CF+ → F + CF continuously increase with increasing CF4 content.

The distribution of F-containing species in atmospheric nanosecond He/CF4 plasma with downstream dielectric material

“…Our results are consistent with Iwase's work [36]. Bai et al [13] reported that the concentration of CF + 4 is greater than that of CF + 3 because the Penning ionization reaction between inert gas and CF 4 were not considered in their simulation.…”

“…However, when the content of fluorine groups were low, the holdoff voltage decreased. Bai et al [13] pointed out that the inhibitor precursor F-containing species played important roles in anisotropic etching. However, due to the extremely low sticking probability, CF 3 had no evident influence on the forming of the protective layer due to its extremely low sticking probability [14].…”

Numerical investigation on the CH4/CO2 nanosecond pulsed dielectric barrier discharge plasma at atmospheric pressure

“…Compared with the traditional DBD excited by alternating current power supply, the nanosecond pulsed DBD (called NPDBD) effectively generates more stable, homogenous and highly chemical activity non-equilibrium discharge plasma. [15][16][17][18][19][20][21] Khalifeh et al have experimentally studied extra pure H 2 production through CH 4 decomposition using the NPDBD plasma and Pt-Re catalyst. 22 Zhang et al have researched temporal evolution characteristics and chemical kinetics of the non-oxidative CH 4 conversion in the well-designed repetitively NPDBD plasma reactor.…”

Numerical Investigations on Methane–Air Nanosecond Pulsed Dielectric Barrier Discharge Plasma-Assisted Combustion

“…The simulation model consists of the homemade one-dimensional plasma model and the two-dimensional combustion model based on software CHEMKIN-PRO. In previous studies, the plasma model has been implemented and validated for various NPDBD plasmas in different gas compositions. − Figure shows the schematic of the NPDBD plasma-assisted combustion system used in this work. The descriptions of the NPDBD plasma model and the planar shear flow combustion model are presented in Sections and 4.2, respectively.…”