Spatial distribution of Ar on the Ar-ion-induced rippled surface of Si

We have measured spatial distribution of Ar atoms on the rippled surface generated on Si undergoing 60 keV Ar bombardment at a 60 degrees angle of ion incidence. Elemental mapping and line scans using energy dispersive x-ray spectrometry attached in a scanning electron microscope confirmed that subsequent to the interpeak shadowing of incident ion flux, most of the argon atoms are incorporated around the middle part of the front slope of ripple facing the ion beam as compared to the rear slope. The spatial extension of the argon rich phase amounts about half of the ripple wavelength. The experimentally observed compositional heterogeneity between the two faces of the ripples agrees reasonably good to the well-known Monte Carlo ion simulator TRIM based theoretical calculations.