Using scanning tunneling microscopy, x-ray photoelectron spectroscopy,
and low-energy electron diffraction, we have studied clean and
Ni-containing Si(1 0 0) surfaces and shown that the Ni contamination can
easily appear at the Si(1 0 0) during its annealing at high temperature
(1230 °C) because of migration of this impurity from heated parts of
the sample holder, even though they are nominally Ni-free. The
difference of dimer-vacancy (DV) defects, which are common features of
Si(1 0 0), and their patterns on both surfaces is examined. It is also
found that the density of DV defects on the Ni-contaminated surface is
proportional to the number of Ni atoms. The analysis indicates that the
fully saturated DV structure, i.e., Ni-induced Si(1 0 0)(2 × n)
phase contains one metal atom per defect. The findings are valuable for
constructing atomic models of defects on the Si(1 0 0) as well as
preparation of clean Si(1 0 0) substrate and monitoring the Ni
segregation on its surface. In addition, the results can be useful for
Ni silicide metal-contact formation in metal-oxide-semiconductor
field-effect transistor technology.”