NEW FEATURES OF C-TYPE DEFECTS ON THE SI(100) SURFACE OBSERVED BY SCANNING-TUNNELING-MICROSCOPY

New features of the C-type defects on the Si(100) surface have been fo und by a scanning tunnelling microscope. The depressions of these defe cts appear to be surface vacancies. Two protrusions of most C-type def ects are actually not equal and the smaller one can be transferred to the adjacent site in the depression to form a new defect. During biase d tip scanning new C- or Cl-type defects can emerge on the surface. Th e dimer buckling induced by the defects appears not only in filled-sta te images but also in empty-state images, and apparent buckling direct ions of both are opposite.