An Investigation of the Si(111) 7×7 Surface Structure by RHEED

Abstract

A clean Si(111) surface showing a 7×7 superlattice structure has been investigated in detail by RHEED with changes of azimuthal angle, glancing angle, and surface temperature. For the 7×7 structure, the mean intensity distribution of the reciprocal lattice rods was estimated from the intensity analysis of various RHEED patterns. A Patterson function was calculated using the mean intensity distribution. A new structural model which satisfies the Patterson function has been obtained. This model contains some scattering matter arranged in a regular triangular form with side 2 a , a being the size of the substrate unit mesh. The intensity distributions calculated from this model agreed well with that obtained from RHEED and LEED patterns.