Evaluation of the probing profile of scanning force microscopy tips

It is demonstrated that a high-temperature-treated (305) surface of a SrTiO3 crystal can be used to evaluate the probing profile of AFM tips routinely, to provide a means of selecting perfect tips and to evaluate possible image distortions. This is important in order to recognize typical AFM artifacts which are caused by tips with truncated or twinned peaks which occur rather often in the case of microfabricated AFM needles. By means of selected needles, it is shown that also defective tips can give apparently rather perfect atomic resolution from flat crystal surfaces. Scope and limitations of the resolution of structural defects are discussed as the criterion for real atomic resolution