Kink-induced buckled dimers on Si(001) and Ge(001) at room temperature studied by scanning tunneling microscopy

Abstract

The structure of kinks at monatomic steps on Si(001) and Ge(001) is investigated by high-resolution scanning tunneling microscopy at room temperature. In addition to previously known asymmetric-dimers at edges of the ${\mathit{S}}_{\mathit{A}}$ and ${\mathit{S}}_{\mathit{B}}$ steps running parallel and perpendicular to dimer rows in the upper terrace, respectively, we have found that kinks at both ${\mathit{S}}_{\mathit{A}}$ and ${\mathit{S}}_{\mathit{B}}$ steps induce buckled (asymmetric-appearing) dimers locally in the connecting dimer rows in the lower terrace. Influence of the kinks on the formation of a c(4\ifmmode\times\else\texttimes\fi{}2) phase of asymmetric dimers at low temperatures is discussed. \textcopyright{} 1996 The American Physical Society.