The influence of the ion–atom potential on molecular dynamics simulations of sputtering

The influence of the ion–atom potential on sputtering parameters calculated with molecular dynamics simulations was last investigated in detail by Harrison in 1980 [J. Appl. Phys. 52 (1981) 1499]. Harrison concluded that except for total yields, layer yields, yields from different crystal orientations and atom per single ion (ASI) distributions, most sputtering properties were relatively insensitive to the choice of ion–atom potential. Since conventional sputtering theory predicts that only the total yields should be dependent on the ion–atom potential, we have reinvestigated this problem with much higher precision. We find that only the total yields are sensitive to the ion–atom potential, and these appear to depend on the strength of the ion–atom potential at a separation radius of approximately 0.7 A rather than the larger separation radius range of 0.8–1.1 A suggested by Harrison. The total sputtering yields also were found to correlate well with the stopping power computed for each of the ion–atom potentials that were tested. 2003 Elsevier B.V. All rights reserved. PACS: 79.20.)m; 79.20.Ap; 79.20.Rf