Self-organized silver nanoparticles on SiO2 surface nanopatterns induced by MeV ion implantation

Investigations on MeV ion-induced pattern formation are scarce, even though this energy regime is ideal for testing the classical continuum models in this field, formulated for low and medium ion energies ( ≤ 200 keV). In this work, we study the surface morphological evolution and pattern formation in SiO 2 implanted with 1.2 MeV Ag + ions at an incidence angle of 60°. The ion implantation was performed at room temperature with ion fluences from 0.4 × 10 17 cm −2 to 2.0 × 10 17 cm −2 . Surface characterization was performed by SEM, AFM, and energy dispersive spectroscopy (EDS). At the lowest fluences, localized crest-like protrusions on a flat background were observed, a feature not predicted by continuum models. Their origin is attributed to pre-existing manufacturing defects, consistent with recent theoretical models. For intermediate fluences, a background ripple pattern emerges and surrounds these protrusions until, at the highest fluences, the ripples dominate the surface. Notably, silver nanoparticles formed preferentially on the crests of both protrusions and ripples due to a geometrical shadowing effect. The optical absorption of the samples shows a localized surface plasmon resonance (LSPR) at 405–412 nm, characteristic of silver nanoparticles. These results position MeV ion implantation as a single-step technique for SiO 2 surface functionalization in plasmonics.