Atomic nature of reconstructed Si(110).

Abstract

Using scanning tunneling microscopy (STM) we have measured constant-current topographies of reconstructed Si(110). While low-energy-electron diffraction (LEED) showed a 4\ifmmode\times\else\texttimes\fi{}5 pattern with dominant 2\ifmmode\times\else\texttimes\fi{}1 contributions, in STM a 2\ifmmode\times\else\texttimes\fi{}5 periodicity of atomic building blocks is observed. These building blocks are arranged in the form of chains along [\ifmmode\bar\else\textasciimacron\fi{}110]-like directions and show a tendency to pairing, which accounts for the 4\ifmmode\times\else\texttimes\fi{}5 LEED results. The 2\ifmmode\times\else\texttimes\fi{}1 reconstruction, which was previously ascribed to a high-temperature phase of Si(110), is explained by a reduction of chain length caused by the generation of defects with increasing temperature.