Scanning-tunneling-microscopy images of Ge adsorbed on an As-covered Si(001) surface

GROWTH OF Si ATOMIC WIRES ON Pb-MEDIATED Si(111)7 × 7 SUBSTRATE

The growth of the self-assembled Si atomic wires on Pb -covered Si (111) 7 × 7 substrate has been studied using homemade scanning tunneling microscope (STM) at room temperature (RT). These surfactant-mediated epitaxially grown Si atomic wires ( SiAWs ) are quite stable at RT. It is interesting that they always appear in pairs having a distance of ~9 Å in between them. They have only three special growth directions, parallel to the three possible crystal directions of the Si (111) substrate underneath. The SiAW can be imaged down to few mV bias voltages, and the voltage current characteristic investigated with scanning tunneling spectroscopy reveals metallic electronic structure of this special kind of SiAW .