Statistical treatment on the formation of Si(100) 2×n surface

Abstract

Si(100) 2×n structure observed recently by scanning tunneling microscopy (STM) is analyzed by a statistical method. It is shown that the defect formation energy should be positive and the stability of the structure is induced by configurational entropy term in the free energy not only by the internal energy term. The formation energy is estimated as to be 0.14 eV per one missing-dimer defect. It is emphasized that the real space image such as that of STM provides the dynamical quantity associated with the reconstruction of the surface.