Imaging artefacts in atomic force microscopy with carbon nanotube tips

Dynamic atomic force microscopy (dynamic AFM) with carbon nanotube tips has been suggested as an enabling tool for high precision nanometrology of critical dimension features of semiconductor surfaces. We investigate the performance of oscillating AFM microcantilevers with multi-walled carbon nanotube (multi-walled CNT) tips interacting with high aspect ratio structures while in the attractive regime of dynamic AFM. We present experimental results on SiO2 gratings and tungsten nanorods, which show two distinct imaging artefacts, namely the formation of divots and large ringing artefacts that are inherent to CNT AFM probe operation. Through meticulous adjustment of operating parameters, the connection of these artefacts to CNT bending, adhesion, and stiction is described qualitatively and explained. (Some figures in this article are in colour only in the electronic version)