Toward a Quantitative Understanding of the Effect of Tip Shape on Measurements of Surface Roughness by AFM Based on Computer Simulations

Abstract

Measurements of surface roughness by atomic force microscope (AFM) may contain an important error from the finite size of AFM tips. The error is rarely evaluated in experiments due to the lack of a quantitative mathematical description of the effect of tip shape on measurements of the roughness of three-dimensional (3D) surfaces. By introducing a parameter called the normalized tip width, we determined approximate generalized formulas that describe the dependencies of three main types of AFM roughness measurements on the parameters of a tip–surface system for Gaussian rough surfaces based on simulations. General models or a practical database may be extracted after establishment of formulas for more types of surfaces.