Electrical conduction of Ge nanodot arrays formed on an oxidized Si surface

摘要

Carrier transport mechanism on Ge nanodot arrays formed on SiO_2 monolayer covering over the Si surface is investigated by microscopic four-point-probe measurements combined with core-level photoemission spectroscopy and scanning tunneling microscopy. Different conduction natures are found depending on whether or not the nanodots and the substrate are directly connected by subnanometer-sized voids penetrating the SiO_2 layer. In the presence of the voids, conductivity is regulated by the dot-size through quantum-size effect.