Supercomputer modeling of the ion beam sputtering process: full-atomistic level

摘要

A new method for supercomputer atomistic modeling of the ion beam sputtering process is presented allowing atomistic modeling of the systems consisting of 10~6 - 10~8 atoms. Deposition process is organized as a sequence of molecular dynamic cycles in which deposited atoms interact with the substrate with earlier deposited atoms and form new chemical bonds. The method is applied to the modeling of SiO_2 thin optical films. For interatomic potential energy calculation the original DESIL force field with high computational efficiency has been developed. Atomistic modeling of the deposition processes with different Si atom energies is performed for the films with thicknesses up to 30 nm (about one million deposited atoms). Dependence of thin film density on film thickness is investigated. It is found that film densities depend on the energy of sputtered atoms and exceed the density of fused silica substrate by 0.1-0.2 g/cm~3. In all experiments interface layers with the thicknesses of about 1-2 nm between thin film and substrate are observed.