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

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.