On the Competition Between the Phenomena Involved in the Aerosol Dynamics in Sputtering Nonequilibrium Plasma

TL;DR

This study combines plasma, cluster, and aerosol models to analyze dust formation in sputtering plasma, revealing how sputtering yield influences particle characteristics and dynamics.

Contribution

It introduces an integrated modeling approach to investigate aerosol dynamics in sputtering plasma, highlighting the impact of sputtering yield on particle formation and behavior.

Findings

Particle density reaches 10^7-10^8 cm^-3 in minutes

Particle mean diameter is about 40 nm with bimodal distribution

Higher sputtering yields increase density and coagulation, but limit nucleation

Abstract

- We made use of a combination of three models that describe plasma equilibrium, cluster kinetics and aerosol dynamics in order to investigate solid carbonaceous dust formation in a DC gas discharge where the carbon source is provided by a graphite cathode sputtering. This enabled us to determine the time-evolution of some of the particle characteristics, e., g. total density, mean-diameter, average-charge as function of the sputtering yield. We showed that for few minutes discharge duration, the particle density reaches 10 7-10 8 cm-3 , the particle mean diameter is approximately 40 nm and the particle size distributions are bimodal for all the investigated conditions. We also showed that the variation of the sputtering yield affects in a quite unexpected way the interplay between the phenomena involved in the aerosol dynamics. Basically, larger sputtering yields result in larger density and coagulation rate on one hand, and in a limited nucleation and surface sticking kinetics on the other hand.