Electric properties of nanoscale contacts on Si 111/surfaces

We have investigated the electric properties of nanoscale contacts on Si 111.-7=7 surfaces with a scanning tunneling microscope STM.. The contacts between a W STM tip and Si substrates exhibit Schottky-type rectification, whose properties are obviously different from the conventional plane diodes. The current variation during tip retraction from the contact region indicates the influence of Si atoms between the tip and substrates, as well as the contact size effects, which result from the Si atom removal with the present experimental technique. q1998 Elsevier Science B.V. All rights reserved