Morphological evolution of Ge/Si nano-strips driven by Rayleigh-like instability

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Marco Salvalaglio - , Dresden University of Technology, Innovations for High Performance Microelectronics (Author)
  • Peter Zaumseil - , Innovations for High Performance Microelectronics (Author)
  • Yuji Yamamoto - , Innovations for High Performance Microelectronics (Author)
  • Oliver Skibitzki - , Innovations for High Performance Microelectronics (Author)
  • Roberto Bergamaschini - , University of Milan - Bicocca (Author)
  • Thomas Schroeder - , Innovations for High Performance Microelectronics (Author)
  • Axel Voigt - , Dresden University of Technology (Author)
  • Giovanni Capellini - , Roma Tre University (Author)

Abstract

We present the morphological evolution obtained during the annealing of Ge strips grown on Si ridges as a prototypical process for 3D device architectures and nanophotonic applications. In particular, the morphological transition occurring from Ge/Si nanostrips to nanoislands is illustrated. The combined effect of performing annealing at different temperatures and varying the lateral size of the Si ridge underlying the Ge strips is addressed by means of a synergistic experimental and theoretical analysis. Indeed, three-dimensional phase-field simulations of surface diffusion, including the contributions of both surface and elastic energy, are exploited to understand the outcomes of annealing experiments. The breakup of Ge/Si strips, due to the activation of surface diffusion at high temperature, is found to be mainly driven by surface-energy reduction, thus pointing to a Rayleigh-like instability. The residual strain is found to play a minor role, only inducing local effects at the borders of the islands and an enhancement of the instability. Published by AIP Publishing.

Details

Original languageEnglish
Article number022101
Number of pages5
JournalApplied physics letters
Volume112
Issue number2
Publication statusPublished - 8 Jan 2018
Peer-reviewedYes
Externally publishedYes

External IDs

Scopus 85040460434
ORCID /0000-0002-4217-0951/work/142237387

Keywords

Keywords

  • SURFACE-DIFFUSION, CAPILLARY INSTABILITIES, THIN-FILMS, NANOSTRUCTURES, STABILITY, MODEL, GE, SI