Coulomb blockade and staircases in self-organized Ag nanoclusters on Sb-terminated Si(100) surfaces

Nanometer sized Ag clusters with uniform size distribution were self-organized on an Sb-terminated Si(100) surface. Tunneling spectroscopy showed that the conduction properties of the Ag nanoclusters gradually changed from semiconducting to metallic with the increase of Ag coverage owing to the onset of surface conduction channels between adjacent Ag nanoclusters. In the local tunneling current-voltage measurements, Coulomb blockade and staircases were clearly observed at room temperature. These phenomena are well described by the lateral tunneling between the Ag nanoclusters.