STM studies: spatial resolution limits to fit observations in nanotechnology

Atomically resolved Scanning Tunneling Microscopy (STM) images are nowadays currently obtained on flat surfaces without any special STM tip preparatio n. On the contrary, imaging of three-dimensional nanometer-scale objects ex hibiting very much inclined facets, requires the use of STM tips with an ap propriate geometry. The tip shape has to be controlled over the whole lengt h that corresponds to the height of the object to be imaged. The cone angle of the tip has to be smaller than the tilt angle of the imaged facets. The se criteria are also required when STM tips are used for patterning of nano meter-scale dots. In this paper, we will present the spatial resolution lim its determined for these tips on different calibration gratings as well as first results obtained on nanometer scale patterning. (C) 2000 Elsevier Sci ence B.V. All rights reserved.