ION SPUTTERING NANOSTRUCTURING CRYSTALLINE MgF2 SURFACE AND ITS ENERGY-DEPENDENT SURFACE ROUGHNESS

Abstract

The topography of crystalline MgF 2 surfaces eroded by low energy Ar + beam has been investigated by atomic force microscopy (AFM). Applying the optimal experimental parameters, regular nanoripples of 83 nm wavelength have been fabricated on the surface and the ripples direction is parallel to the ion beam. It is also found that both the surface roughness and the ripple direction are of obvious energy dependence, which we attribute to competing balance between kinetic roughening and ion-induced surface diffusion. We also explain why the roughness value of produced ripples reaches maximum at a rather medium energy point, instead of increasing with the ion energy.