ATOMIC-SCALE FLATTENING AND CHARACTERIZATION OF A YBCO FILM SURFACE

Surface flattening of YBCO films with Ar ion beam exposure was studied . Atomic force microscopy (AFM) observation revealed that the surface roughness decreases with increasing ion beam exposure time. The mechan ism of flattening was explained by the angular-dependent etching chara cteristics. A flattening effect on an atomic scale with a mean roughne ss of 0.8 nm was observed. Electrical measurements and Raman spectrosc opy indicated that superconductivity and crystallinity of the films ex posed to the ion beam were damaged due to the ion bombardment.