Study of H:Si(113)2×2 Structure by Scanning Tunneling Microscopy and Ab Initio Calculation

Abstract

The H:Si(113) structure has been studied by scanning tunneling microscopy and ab initio caluculation. After exposing hydrogen atoms on a clean Si(113) surface, 2×n:H (n = 2,3) structures form. High-resolution STM images reveal that these structures show three types of protrusions. Islands growing one-dimensionally are observed on the local surface area. We performed an ab initio calculation for several possible structural models of the 2×2:H structure. Comparison of observed STM images and simulated images obtained by ab initio calculation clarifies that the structural model composed of a pentamer without an interstitial atom and two three-coordinated site atoms is most favorable. Energy analysis indicates that this structural model is most stable. Based on these results, a structural model of the 2×3:H structure is also proposed. The 2×n:H structures are expected to have anisotropic surface strain. [DOI: 10.1380/ejssnt.2010.261]