Scanning tunneling microscopy observation of self-affine fractal roughness in ion-bombarded film surfaces

Abstract

We describe a straightforward method for obtaining a precise value for the fractal dimension (self-affine scaling exponent) of a surface, via scanning tunneling microscopy. It is applied to investigate ion-beam erosion of an iron film surface, provoding strong support for the applicability of scaling theory to submicron erosion processes. A self-affine surface with scaling exponent H=0.53\ifmmode\pm\else\textpm\fi{}0.02 is observed to develop.