Energy-dependent wavelength of the ion-induced nanoscale ripple

Abstract

The wavelength variation of an ion-beam-induced nanoscale ripple structure has received much attention recently due to its possible application in nanotechnology. Here we present results of Ar⁺-bombarded Si in the energy range 50-140 keV to demonstrate that with beam scanning the ripple wavelength increases with ion energy and decreases with energy for irradiation without ion beam scanning. An expression for the energy dependence of the ripple wavelength is proposed, simultaneously taking into account the effect of thermally activated surface diffusion and ion-induced effective surface diffusion.