File(s) under embargo

Reason: Publisher requirement

149

days

5

hours

until file(s) become available

Molecular dynamics simulations of the growth of Ge on Si

journal contribution
posted on 25.02.2020 by Ying Zhou, Adam Lloyd, Roger Smith, Kirill A. Lozovoy, Alexander V. Voitsekhovskii, Andrey P. Kokhanenko
The initial stages of the growth of germanium on the dimer reconstructed Si(100) surface is modelled using molecular dynamics (MD). Pyramidal island structures are observed to form despite MD being carried out at a deposition rate faster than experiment. By an examination of transitions that can occur from intermediate structures that form in the MD simulations, growth mechanisms can be identified. The initial wetting occurs as a result of Ge atoms diffusing into the trenches between the dimer rows. This results in Ge-Ge or Ge-Si dimer chains growing in rows perpendicular to the original Si-Si dimer rows on the surface. It is shown how strained Ge pyramids with square bases can form by diffusing atoms joining together adjacent dimer rows. From these initial square-based structures, complex concerted motions are observed in which atoms in lower layers ‘climb up’ to higher layers. Similar structures grown in the pure Si case exhibit much higher energy barriers for the ‘climbing up’ process indicating that the effect of strain is to reduce the energy barriers for pyramid formation. In addition to the investigation of atomistic growth processes, surface energy effects are also examined, which show that a germanium-covered Si(100) surface containing shallow-angled pyramids is energetically more favourable than that grown as a flat monolayer.

Funding

Royal Society of London

History

School

  • Science

Department

  • Mathematical Sciences

Published in

Surface Science

Volume

696

Publisher

Elsevier

Version

AM (Accepted Manuscript)

Rights holder

© Elsevier

Publisher statement

This paper was accepted for publication in the journal Surface Science and the definitive published version is available at https://doi.org/10.1016/j.susc.2020.121594.

Acceptance date

21/02/2020

Publication date

2020-02-27

Copyright date

2020

ISSN

0039-6028

Language

en

Depositor

Prof Roger Smith. Deposit date: 21 February 2020

Article number

121594

Exports

Logo branding

Exports