Structure of Bi-Dimer Linear Chains on a Si(100) Surface: A Scanning Tunneling Microscopy Study

Abstract

The structure of bismuth-induced Si(100) surfaces has been investigated by scanning tunneling microscopy (STM). Bismuth atoms that adsorb on the surface at 480°C form long linear belts in the Si(100) topmost layer. Each belt consists of two chains of bismuth dimers, and stretches parallel to the ×2 direction of the terrace of the clean Si(100)(2 ×1) surface. From the STM images taken after hydrogen adsorption on the surface, we found that the linear chains of bismuth dimers substitute for four Si-dimer rows on the terrace. We proposed a structural model for the bismuth-dimer chains.