Evolution of ripple morphology on Si(1Â 0Â 0) by 60-keV argon ions

► This paper deals with 60 keV argon ion induced evolution of ripple morphology on silicon surface at room temperature. ► A large angular window (0-75°), in terms of ion incident angle, was chosen for this study. ► Ripple formation in the angular window of 45°-75°. Ripple wavelength decreases with increasing incident angle. ► The results are attributed to the viscous flow mechanism.