NANOMETER-SCALE SYNTHESIS AND ATOMIC-SCALE MODIFICATION WITH THE SCANNING TUNNELING MICROSCOPE

The structure or composition of a surface may be locally altered in ei ther of two fundamental ways using the scanning tunneling microscope ( STM). A modification of the surface may be induced resulting in the re arrangement and/or removal of surface atoms, or in the transfer of ato ms from the tip to the sample surface. In many recent experiments, the modification of surfaces has involved a single atom or an ensemble of a few atoms. Alternatively, the localized synthesis of a new material from reactants external to the STM tip and sample can be induced usin g at least three experimental strategies. A typical distance scale inv olved in such experiments is 10 nm (i.e., the smallest lateral dimensi on of the material synthesized). Progress in the areas of localized mo dification and localized syntheses with the STM (with greater emphasis on the latter) is summarized in this review.