We investigated the physical sputtering of silicon dioxide NOD surface with a-quartz structure due to Ar ion bombardments using molecular dynamics simulation. The potential energy function (PEF) developed by Feuston and Garofalini was used to describe surface atoms' interaction, which consisted of pairwise and tripletwise interactions. The interaction of Ar ion with Si and 0 atoms of surface was modeled by Moliere PEF. The ion incident energies, E-i, were 50, 100 and 200 eV. We varied the ion incident angles from 0degrees to 85degrees. The surface of the substrate was allowed to successively evolve during ion bombardment. We obtained the characteristics of ion implantation into the substrate and sputtering of surface atoms from these calculations. (C) 2002 Published by Elsevier Science B.V.