Gold-induced ordering on vicinal Si(111)

A vicinal Si(111) surface covered with a sub-monolayer amount of Au has been studied by RHEED. For a sample misoriented by 8.46 degrees towards the [(1) over bar (1) over bar 2] azimuthal direction at a coverage equal to 0.20 ML of Au, the RHEED pattern showed a regular distribution of monoatomic steps with the staircase width equal to 18.88+/-0.33 Angstrom. Au-induced order was identified with a (755) facet of Si. Regularly spaced steps were stable within the investigated range of temperatures from 130 to 470 K. Upon further increase of the Au-coverage the periodicity was disturbed and al a coverage of about 0.50 ML of Au onset of (root 3 x root)R30 degrees reconstruction was visible. (C) 1997 Elsevier Science B.V.