ATOMIC-STRUCTURE OF SB SI(111)-5-ROOT-3X5-ROOT-3 SURFACE/

We investigated 5 root 3x5 root 3 atomic structure of an Sb-passivated Si(lll) surface using low energy electron diffraction (LEED) and scan ning tunneling Microscope (STM). This interesting structure with large unit cell has been analyzed with high resolution STM images in detail . The proper structural model is suggested in order to describe the ST M image and other experimental results. They are understood within the frame of Si(111)-5x5 DAS (dimer adatom stacking fault) structure havi ng the site-selective replacement of Si atoms with Sb atoms.