Revisiting the 7 × 7 reconstruction of Si(111)

Scanning Tunneling Microscopy (STM) on boron-doped, p-type Si(111) confirmed the main structural features of the 7 × 7 reconstruction of nearly intrinsic n-type material, in particular the three-fold rotational symmetry. In the p-doped material, one distinct maximum is absent in about every fifth cell. This is attributed to a surface-boron dopant, implying an appreciable surface segregation of boron. © 1985.