Ripple topography and roughness evolution on surface of polycrystalline gold and silver thin films under low energy Ar-ion beam sputtering

► Ripple topography measured on gold and silver films sputtered with Ar+ 650 eV is compared to theory. ► Ripples were always oriented parallel to the ion beam direction. ► Ripples wavelength decreased with increasing energy and ion flux. ► Three regimes for roughness evolution have been observed as function of the angle of incidence. ► The lower roughness observed around 45° on gold and 60° on silver films is promising for polishing applications.