Directionally resolved measurements of momentum transport in sputter plumes as a critical test for simulations

Abstract

A 50×50mm2 copper target is sputtered by an ion beam at angles of incidence from 0° to 90°. The resulting sputter plumes are characterized directionally resolved using a compact and maneuverable force probe. It measures the momentum flux of particles released due to sputtering or reflection inside the sputter plume. Argon ions at energies from 320 to 1220 eV are studied. As expected, the directional distributions are sensitive to the angle of incidence. The ion energy has significant influence only on the magnitude of forces and not their directional distribution. The experimental results are compared with simulations based on the “stopping and range of ions in matter” code (SRIM). The general trends of the directional distributions of forces match reasonably with simulations. However, the simulations overestimate the forces at normal incidence and shallow angles of incidence.