COMPARATIVE SCANNING-TUNNELING-MICROSCOPY INVESTIGATIONS OF NANOSTRUCTURES PREPARED BY DIFFERENT TECHNIQUES

Conducting nanoscale structures (dots, particles and wires) are fabric ated by means of four different techniques on chemically cleaned, H-te rminated Si substrates and investigated using a scanning tunnelling mi croscope (STM) operated under high-vacuum conditions. We distinguish b etween STM tip-independent or 'global' techniques (formation of colloi ds by wet chemical methods: condensation of particles from the vapour phase in a low-pressure background noble gas) and tip-assisted or 'loc al' techniques (field-induced transfer of tip material; electron-stimu lated decomposition of organometallic compounds). These fabrication te chniques are compared and evaluated, e.g., with respect to the particl e stability on the substrate surface at room temperature and the capab ility of manipulating individual particles? in order to address the is sue of designing prototype hybrid structures by the controlled assembl ing of nanoparticles and electrically connecting these structures to t he 'outside world' by means of an STM.