Self-assembled metal/molecule/semiconductor nanostructures for electronic device and contact applications

We report a fabrication approach in which we combine self-assembled metal/molecule nanostructures with chemically stable semiconductor surface layers. The resulting structures have well controlled dimensions and geometries (similar to 4 nm Au nanoclusters) provided by the chemical self-assembly and have stable, low-resistance interfaces realized by the chemically stable semiconductor cap layer (low-temperature grown GaAs passivated by the organic tether molecules). Scanning tunneling microscope imaging and current-voltage spectroscopy of nanocontacts to n-GaAs fabricated using this approach indicate high quality, ohmic nanocontacts having a specific contact resistance of similar to 1 x 10(-7) Omega . cm(2) and a maximum current density of similar to 1 x 10(7) A/cm(2), both comparable to those observed in large area contacts. Uniform 2-D arrays of these nanocontact structures have been fabricated and characterized as potential cells for nanoelectronic device applications.