MONATOMIC STEP STRUCTURE ON THE SI(001) SURFACE

The atomic structure of the monatomic steps on the Si(001) surface is investigated by scanning tunneling microscopy. The kink at the interse ction of the SA and Sg steps induces a strong buckling along the rebon ded dimer row in the lower terrace. On the upper terrace of the Sg ste p, the kink induces a local p(2x2) structure directed toward the cente r of the step. The strains of second-layer atoms supporting the dimers are responsible for the reconstruction near the monatomic steps on th e Si(001) surface.