An investigation into improving the tip fabrication technique for Atomic Force Microcopy (AFM) tips has been undertaken. The problems addressed here relate to the artifacts that are produced from imaging high aspect ratio (depth/width) features with standard AFM pyramidal tips. Standard tips, while having a regular geometry present a problem: the pyramid's base is 3-5 microns square and the walls are angled at 55°. This tip shape can cause a great deal of “smoothing” to high aspect ratio topological features, whether they are a few nm or a few μm in height. The use of electron beam grown microtips eliminates many of the tip artifacts found when using standard pyramidal tips. Actual growth of tips is quite easy. Once the SEM is set up properly (focused and stigmated) the scan generator for the beam is turned off, placing the microscope in the spot mode. The beam spot is placed at the point where a tip is desired and left for several minutes.
Probing local electronic property of two-dimensional materials by atomicforce microscopy