Surface nanopatterns on Si(100) by normal-incidence ion sputtering with simultaneous metal incorporation

Normally, self-organized surface nanopatterns produced by ion beam sputtering (IBS) result in nanodot or nanoripplemorphologies depending on geometrical considerations. However, recent studies show that additional contributions should be considered when multielemental targets are involved due to the eventual development of a modulation between the surface composition and its morphology. This fact can be extended to targets irradiated with the presence of intentional or accidental impurities (mainly metals) on the surface that, for example, may be responsible for triggering the pattern formation at (near) normal ion incidence onmonoelemental semiconductors such as silicon. In this chapter, we deepen in the role of simultaneous metal incorporation in pattern formation on Si(100) surfaces by normal-incidence IBS with 1 keV Ar⁺. We show that the level of metal incorporation can additionally be used to tune the pattern morphology and, in particular, selectively produce unconventional nanohole patterns for metal levels higher than those present in the standard nanodot pattern counterpart. We examine the parameter window for the production of different morphologies to verify the morphological and compositional correlation. Finally, we highlight relevant mechanisms that could drive to such pattern selectivity.