Directional protrusion effect of Ge surface induced by argon cluster oblique bombardment

Abstract

The Gas Cluster Ion Beam (GCIB) bombardment, serving as a pivotal technique for nanoripple formation on material surfaces, has attracted growing attention. In this study, molecular dynamics simulations were employed to investigate the bombardment of Ge surfaces using Ar3000 clusters with a cluster energy of 50 keV, aiming to understand the underlying mechanism of nanoripple formation. The result demonstrates that there will be a directional pit–protrusion morphology formation under the cluster oblique bombardment. Quantitative number analysis of the sputtered and migrated atoms within 0–12 ps indicates that the atom migration reaches a peak at an incident angle of 60°. In this case, a construct characterized by the higher protrusion and a shallower pit is formed. The result contributes to a better understanding of the optimal nanoripple formation on the Ge surface and other material surfaces, while also providing insights for optimizing surface processes via the GCIB technique.