Low energy electron diffraction and scanning tunneling microscope observation of Ba induced step arrangement of vicinal Si(111) surface

Adsorbed structures of Ba on Si(111) surfaces have been investigated by LEED (Low Energy Electron Diffraction) and STM (Scanning Tunneling Microscopy). We compared the vicinal substrate surface with the flat substrate surface of which the inclination from the (111) plane is small in order to confirm whether the step arrangement is caused by the proper miscut angle of substrate. On the vicinal Si(111) surface, one-dimensional 10 × 1 structure was observed by LEED and the step arrangement of 10-times the unit length terraces with a double-layer step height has been observed by STM after annealing at about 950°C. On the flat Si(111) surface, 3 domains of 5 × 1 have been observed in the same temperature range by LEED and STM. It was confirmed that the step arrangement was caused by a cooperation of a proper miscut angle of the substrate and the superstructure on the terrace.