Au-induced reconstructions of the Si(111) surface

Abstract

Au-adsorbed structures (∼1 ML) on the Si(111) surface are studied using a scanning tunneling microscope. In the initial stage of deposition, locally Au atoms are adsorbed onto the Si(111) surface with a 5×5 periodicity. At lower coverage, images showing a 5×2 periodicity are recorded, in which there are a dark line and two atomic rows running in the [1̄01] direction in a five times period. In each atomic row, atoms are arranged in a two times period along the row. At higher coverage, images showing a (3)1/2×(3)1/2 structure are also recorded. In these images, in addition to the (3)1/2 ×(3)1/2 periodicity, there is an undulation which is explained as a phase shift of the (3)1/2 ×(3)1/2 structure.