Structural evolution of the Si(113) surface: Ab initioand tight-binding molecular dynamics calculations

The structural evolution of the Si(113) surface is investigated by ab initio calculations and by tight-binding molecular dynamics calculations using the environment-dependent tight-binding Si potential. In this study, it is found that 3×2 and 3×1 phases have interstitial structures and the transition from 3×2 to 3×1 phase results from the increasing of interstitial atoms. The existence of the interstitial structures is proved by the analysis of scanning tunneling microscopy (STM) images and the calculation of surface core level shifts using final state pseudopotential theory. The study of adsorption energy clarified that the phase transition from the 3×2 to 3×1 interstitial surface plays an important role in the behavior of the 113 facet in the selective epitaxial growth of Si(001). It is also found that the domain boundary observed frequently in the filled state STM images of Si(113) is formed by the local 3×1 interstitial structure on the 3×2 interstitial surface.