An ab initio study of the Te surfactant on Ge/Si(0 0 1)

ÇAKMAK M., Srivastava G., Ellialtıoğlu S. Ş.

Surface Science, vol.566-568, no.1-3 PART 2, pp.719-722, 2004 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 566-568 Issue: 1-3 PART 2
  • Publication Date: 2004
  • Doi Number: 10.1016/j.susc.2004.06.005
  • Journal Name: Surface Science
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.719-722
  • Keywords: density functional calculations, chalcogens, germanium, silicon, growth, chemisorption, ELECTRONIC-STRUCTURE, ADSORPTION, SI(001), DESORPTION, STATE, SE
  • TED University Affiliated: No

Abstract

We present ab initio density functional calculations for the surfactant effect of Te on the Ge/Si(001) surface. Direct deposition of a Ge layer on top of the Si substrate is found to be energetically favorable by 0.50 eV than the Ge-interdiffused case. We do not find any significant energy difference when we used 1 monolayer (ML) Te as surfactant within (1×1). For Te adsorption within the (2×2) surface reconstruction, we have considered two models for each of 1 ML Ge and 2 ML Ge case: (i) bridge model (Te atom is at the top of Ge-Ge dimer) and (ii) anti-bridge model (two Te atoms saturate the four dangling bonds at two neighboring Ge-Ge dimers in a row). For the 1 ML Ge case we have found that the anti-bridge model is energetically favorable by 0.70 eV than the bridge-model. However, when we have considered the same models for the 2 ML Ge case, this energy difference increases to 0.90 eV. © 2004 Elsevier B.V. All rights reserved.