Why are physical sputtering yields similar for incident ions with different masses?—physical sputtering yields of the Lennard–Jones system

Abstract Plasma etching of nano-meter-scale complex structures for semiconductor device manufacturing requires a deeper understanding mechanisms. For example, it is known experimentally that the sputtering yield material tends to have weak dependence on mass incident ions except extremely light such as helium. To understand this property, system atoms interacting with Lennard–Jones (LJ) potentials was evaluated molecular dynamics simulation. As simplest possible case involving two atomic species, single-element face-centered-cubit (fcc) LJ solid surface purely repulsive examined, which emulates sputtered by noble-gas ions. The at specific ion energy depends only parameters, i.e. ratio and parameter representing relative interaction range between atom ion. real materials our concern used in plasma etching, these parameters found be relatively limited. It also physical weakly narrow range. Because simple model predicts mass, considered generic property sputtering, independent detailed interactions species.