Imaging resolution of AFM with probes modified with FIB

• Published in: Micron (Oxford, England : 1993) England : 1993), 2014-11, Vol.66, p.23-30
• Main Authors: Skibinski, J., Rebis, J., Wejrzanowski, T., Rozniatowski, K., Pressard, K., Kurzydlowski, K.J.
• Format: Article
• Language: English
• Subjects: AFM; FIB modification; Finite Element Method; Modal analysis; Nanomachining
• ISSN: 0968-4328; 1878-4291
• DOI: 10.1016/j.micron.2014.05.001

•Shape of the AFM probe tips was modified to check the influence of probe shape on imaging quality.•Improvement of phase image and deterioration of tapping mode image was observed with change of working frequency.•Modal analysis of modified AFM probe tips was performed to explain the observed phenomena.•Use of two different frequencies for improved imaging was proposed. This study concerns imaging of the structure of materials using AFM tapping (TM) and phase imaging (PI) mode, using probes modified with focused ion beam (FIB). Three kinds of modifications were applied – thinning of the cantilever, sharpening of the tip and combination of these two modifications. Probes shaped in that way were used for AFM investigations with Bruker AFM Nanoscope 8. As a testing material, titanium roughness standard supplied by Bruker was used. The results show that performed modifications influence the oscillation of the probes. In particular thinning of the cantilever enables one to acquire higher self-resonant frequencies, which can be advantageous for improving the quality of imaging in PI mode. It was found that sharpening the tip improves imaging resolution in tapping mode, which is consistent with existing knowledge, but lowered the quality of high frequency topography images. In this paper the Finite Element Method (FEM) was used to explain the results obtained experimentally.