Effect of hydrogenation on B/Si(0 0 1)-(1 × 2)


ÇAKMAK M., Mete E., Ellialtıoğlu S. Ş.

Surface Science, vol.601, no.18, pp.3711-3716, 2007 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 601 Issue: 18
  • Publication Date: 2007
  • Doi Number: 10.1016/j.susc.2007.04.009
  • Journal Name: Surface Science
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.3711-3716
  • Keywords: density functional calculations, surface electronic phenomena, adsorption, boron, TOTAL-ENERGY CALCULATIONS, AUGMENTED-WAVE METHOD, MOLECULAR-DYNAMICS, BASIS-SET, SI(100), SURFACE, METALS
  • TED University Affiliated: No

Abstract

Ab initio calculations, based on pseudopotentials and density functional theory, have been performed to investigate the effect of hydrogenation on the atomic geometries and the energetics of substitutional boron on the generic Si(0 0 1)-(1 × 2) surface. For a single B atom substitution corresponding to 0.5 ML coverage, we have considered two different sites: (i) the mixed Si-B dimer structure and (ii) boron substituting for the second-layer Si to form Si-B back-bond structure, which is energetically more favorable than the mixed Si-B dimer by 0.1 eV/dimer. However, when both of these cases are passivated by hydrogen atoms, the situation is reversed and the Si-B back-bond case becomes 0.1 eV/dimer higher in energy than the mixed Si-B dimer case. For the B incorporation corresponding to 1 ML coverage, among the substitutional cases, 100% interdiffusion into the third layer of Si and 50% interdiffusion into the second layer of Si are energetically similar and more favorable than the other cases that are considered. However, when the surface is passivated with hydrogen, the B atoms energetically prefer to stay at the third layer of the Si substrate. © 2007 Elsevier B.V. All rights reserved.