Simple Finite Element Model of the Topografiner

H. Cabrera[1], D. A. Zanin[1], L. G. De Pietro[1], A. Vindigni[1], U. Ramsperger[1], D. Pescia[1]
[1]Laboratory for Solid State Physics, ETH Zürich, Zürich, Switzerland
Published in 2014

In our recent experiments we are revisiting the topografiner technology for the imaging of surface topography with a resolution of a few nanometers. In these new technique called Near-Field Emission Scanning Electron Microscopy (NFESEM), low-energy electrons are emitted from a polycrystalline tungsten tip via electric-field assisted tunneling. In order to characterize and improve the capabilities of our microscopes, in particular the vertical and lateral resolutions, we simulate the tunnel junction consisting of a metallic tip placed at distance d from a planar electrode and consider current versus voltage (I-V) and voltage versus distance (V-d) measurements.