| Since the appearance of the first scanning tunneling microscope (STM) in 1981, surface science and technology has experienced a rapid growth because of the powerful tool in the area. As a surface characterization tool, STM has been used not only in physics and chemistry to disclose the surface packing information for fundamental study, but also in material science, biology and semi-conductor industry for characterizing new materials and molecules. As a surface manipulation tool, STM has been used for repositioning surface atoms/molecules and fabrication nano-patterns on different surface materials that demonstrated the fact that STM might become potential tool for building nano-electronic devices for next generation. These studies show that, with STM, a “visual” observation can be realized through all the surface procedures of adsorption, desorption, diffusion, reposition, deposition, dissociation, and finally, possible bond formation. These suggest that the underlying reaction processes could be studied at the atomic level for understanding the intimate fundamental details of reaction mechanisms. In this thesis, a variety of efforts in techniques and operation skills in extracting more surface information with STM, as well as two research topics, have been reported. The experimental effort in STM high temperature imaging led out the first topic study on annealing decanethiol self-assembled monolayers, which disclosed several new surface structures at molecular level. The experimental investigation of optimized bias voltage and tunneling current for obtaining high quality image lead out our second research topic—nano-fabrication. The fabrication studies were performed with a new high current method on the surfaces of Au(111), SAMs/Au(111), and Si(111), from which a surface melting/evaporation model was suggested. These studies enforced the understanding of the instrument and formed the basis of future STM induced chemistry study. |
PDF Full Text Request