Layered Semiconductors as Materials for (Sub)Nanometer Scale Surface Modification with the STM

The local surface modifaction of layered dichalcogenides with the tip of an STM results in a novel class of (sub-)nanometer structures. Time-stable as well as spontaneously growing highly symmetric structures can be generated. In the case of tungsten diselenide (WSe2) the orientation of the structures is strongly related to that of the trigonal lattice of the layered compounds (coherent structures). In contrast, irregular growing structures can be observed on TaSe2. As compared to any other materials reported so far, these layered compounds allow the generation of a remarkable variety of nanometer structures both by tip indentation and by voltage pulsing techniques.