A simple and effective method of evaluating atomic force microscopy tip performance

The morphology of a surface imaged by dynamic force mode atomic force micro scopy is obtained through an interaction between the probe tip and surface features. When the tip is contaminated and the size of the contaminant is c omparable to the size of the features on the sample surface, artifacts attr ibutable to the contaminant are observed to dominate the image. To reduce t he possibility of effects from such artifacts, the tip performance should b e checked by scanning a reference sample of known surface morphology. We de monstrate a simple and effective method of evaluating tip performance by th e imaging of a commercially available biaxially oriented polypropylene (BOP P) film, which contains nanometer-scale-sized fibers. This sample is approp riate for use as a reference because a contaminated tip will not detect the fiberlike network structure. In addition, BOPP has a soft, highly hydropho bic surface of low surface energy, thus ensuring that the tip will not be d amaged or contaminated during the evaluation process.