Effects of CF 4 content on particle densities and reaction pathways in atmospheric-pressure Ar/CF 4 pulsed dielectric barrier discharge plasma

Ar/CF 4 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 CF 4 content on particle densities and reaction pathways in Ar/CF 4 pulsed dielectric barrier discharge plasma at atmospheric pressure. The simulation results indicate that, with increasing CF 4 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 CF 3 and F reach their maximums when the CF 4 content is 70%. In Ar, the electron impacts with Ar are the essential reaction pathways to generate Ar + , Ar m , and Ar * . In CF 4 , the electron impacts with CF 4 are the main paths to produce , , CF + , F + , , CF 2 , F 2 , , F − , CF 3 , and F. Besides, → + F and + F → CF 3 + F − produce part of and F − . Decomposition, recombination, and charge exchange reactions all contribute to the generation of CF 3 and F. In the Ar/CF 4 mixture, Ar + → CF 3 + Ar + and CF 4 + Ar + → + F + Ar produce a great deal of Ar + , , CF 3 , and F. The contribution ratios of the reactions CF 4 + e → CF 3 + F + + 2e and F − + CF + → F + CF continuously increase with increasing CF 4 content.