Molybdenum assisted self-organized pattern formation by low energy ion beam sputtering

The mechanism of formation of self-organized patterns on Si substrate with simultaneous co-sputtering of molybdenum by low-energy ion beam sputtering has been investigated. The experiment was carried out using a 1 keV Ar ion beam at normal incidence with different ion fluence (10¹⁶–10¹⁸ ions.cm⁻²). To explore the mechanism of pattern evolution in the presence of impurities (Mo atom), the morphological details of the samples with different ion fluence, as well as with respect to the distance from the Mo target were examined by atomic force microscopy (AFM). The evolution of the surface pattern depends on the ion fluence and a pattern transition from ripple to ripple + dot, and dot was observed with distance from the Mo target. RBS, XPS and XRR measurements were also carried out to understand the mechanism of the surface evolution process.