A Simple and Effective Method of Evaluating Atomic Force Microscopy Tip Performance

The morphology of a surface imaged by dynamic force mode atomic force microscopy is obtained through an interaction between the probe tip and surface features. When the tip is contaminated and the size of the contaminant is comparable to the size of the features on the sample surface, artifacts attributable to the contaminant are observed to dominate the image. To reduce the possibility of effects from such artifacts, the tip performance should be checked by scanning a reference sample of known surface morphology. We demonstrate a simple and effective method of evaluating tip performance by the imaging of a commercially available biaxially oriented polypropylene (BOPP) film, which contains nanometer-scale-sized fibers. This sample is appropriate for use as a reference because a contaminated tip will not detect the fiberlike network structure. In addition, BOPP has a soft, highly hydrophobic surface of low surface energy, thus ensuring that the tip will not be damaged or contaminated during the evaluation ...