Surface morphology and topography evolution of soda-lime silica glass after 1.0 MeV Si ion bombardment

Abstract

Surface pattern formation on soda-lime silica glass by 1 MeV Si ion irradiation impinging at an angle of 70° with respect to the surface normal has been studied. Modification of surfaces were analyzed for total ion fluences applied between up to ions/cm2. The surface morphology and topography were studied by scanning electron microscopy (SEM), and atomic force microscopy (AFM). These surface techniques enabled the determination of roughness, characteristic wavelengths, and correlation lengths. In addition, electron dispersive spectroscopy (EDS) scans were applied on the surface topography to study the variation of the Si content on the obtained surface patterns. From the measurement of these variables, linear and non-linear regimes were established. At linear regime, the surface morphology develops from an initial flat surface giving rise to ripples for fluences up to ions/cm2. As the ion bombardment continues surface evolve into wrinkles finalizing at cellular-like structures, growing under an anomalous scaling process. The EDS scans indicate the presence of shadowing effects. The morphological changes observed can be explained in terms of a combination of thermal mass diffusion and geometrical factors during ion irradiation, including shadowing and subsequent (secondary) surface erosion effects adapted to few MeV energies.