X-ray structural analysis of an epitaxially grown Ag film/Si(111)-B substrate interface

Abstract

We investigated the structure of the Si(111)-B surface and epitaxially grown Ag(111) film/Si(111)-B substrate interface using surface X-ray diffraction. An analysis of their crystal truncation rod and fractional order rod scatterings revealed a good agreement between the structure of the Si(111)-B surface and previous theoretical studies when taking into account structural inhomogeneity caused by subsurface defects. At the Ag film/Si(111)-B substrate interface, the Si(111)-B surface reconstruction was maintained intact. The experimentally determined positions of Ag atoms were displaced from the ideal Ag(111) bulk sites, and a 3 × 3 periodicity was introduced to the bottom layer of the Ag film at the interface. The 3 × 3 periodic corrugation was transferred, albeit damped, to the upper layer. This transfer was considered to be the origin of the 3 × 3 periodic pattern at the Ag film surface on the Si(111)-B substrate, a pattern observed in our previous scanning tunneling microscope study.