Crater function moments: Role of implanted noble gas atoms

Swelling as a stabilizing mechanism in irradiated thin films

“…We also briefly explore the relationship of our findings to work along a different line of inquiry, namely the Crater Function Framework [12,34,35], which explores the cumulative effect of prompt sputtering and redistribution of target atoms within single ion impacts. Though that approach is focused on very different timescales (a typical collision cascade is completed in only picoseconds, whereas stress relaxes over timescales of seconds), recent additions to the framework include consideration of the effect of implanted ions [36,37]. In these studies, it is found that the implanted atoms are destabilizing at incidence angles above a critical value, which is very different from our finding of stabilization at all angles.…”

Ion-induced nanopatterning of silicon: Toward a predictive model

“…This also provides unprecedented granularity of understanding, as the crater function, and hence, the moments, can be broken down into contributions from sputtered atoms, redistributed atoms, and implanted ions, each of which can be further divided by atomic species. 118,124,125 Nevertheless, despite these advantages, the crater function framework has important limitations of its own.…”

“…More recently, Hobler et al discovered that even noble gas ions make such a contribution. 118 Although, in the steady state, these tend to sputter at approximately the same rate they are implanted, and therefore do not contribute to M (0) , these authors found that the re-sputtered ions tend to originate farther "downstream" than the final resting place of the implanting ions that effectively replace them. This yields a meaningful contribution M (1) (h) even though the noble gas ions tend to remain embedded in the solid surface only a short while before they are eventually re-sputtered.…”

“…Because the additional terms describe the effect of surface curvature on the purely-erosive zeroth moment M (0) , adoption has tended to depend on the energy studied and simulation method used. Studies at higher energies using the BCA now regularly include the terms, 92,[116][117][118][119] because they seem to contribute meaningfully to the coefficients c 11 (h) and c 22 (h) at those energies, and some BCA codes readily allow the simulation of ion impacts on curved targets. On the other hand, studies at lower energies using MD may still omit the terms, 111,115,116 because of the complexity of creating relaxed amorphous targets with varying curvatures, and because erosive effects are not particularly strong at such energies.…”