Comparative study of direct and indirect image‐based profilometry in characterization of surface roughness

Abstract

In this study, we have investigated and compared two different approaches to the characterization of surface structure and roughness. The results of the stylus profilometric method are compared with the results obtained using a relatively novel, indirect, image‐based profilometry. The aim was to evaluate the performance and practical usefulness of the indirect method in the characterization of a surface topography. The indirect approach involved the use of Gwyddion software for analysis of scanning electron microscope (SEM) images and calculation of standard profilometric parameters. It is well known that SEM micrographs provide an excellent tool for visualization and qualitative description of surface topography, including the estimation of corresponding fractal dimensions. The results of this study demonstrate that it is also possible to obtain profilometric parameters from analysis of SEM micrographs with appropriately calibrated gray scale intensity distributions, and that the values of the parameters are comparable to those obtained by classical (stylus) profilometry. Better agreement with results of the direct profilometric method was achieved for parameters related to the distribution of heights than those related to the distribution of depths. Regarding these differences, we have provided arguments indicating that the values of these depths – related parameters obtained by indirect profilometry – are closer to the “true” values than those inferred from the direct profilometry. Generally, the results of this comparative study indicate that indirect image‐based profilometry is a valuable and efficient tool in the characterization of various surface's topographies. Copyright © 2012 John Wiley & Sons, Ltd.