Si(111)53×53-Sb: a surface phase with a variable composition

Using scanning tunneling microscopy, the changes in the morphology and atomic structure of the Si(111)53×53-Sb surface during Sb desorption have been studied. It has been found that the Si(111)53×53-Sb surface phase does not have a definite composition. In attempting to explain the 53×53 long-range order stability in a wide Si and Sb coverage range it has been suggested that Sb atoms partially substitute for the boundary Si dimers in the basic 5×5 dimer–adatom–stacking-fault structure. A possible model of the Si(111)53×53-Sb reconstruction satisfying this requirement has been proposed.