Crystallisation of amorphous germanium thin films

G. Garcia, A. F. Lopeandia, A. Bernardi, M. I. Alonso, A. R. Goni, J. Lábár, J. Rodrfguez-Viejo

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

By combining cross-sectional transmission and scanning electron microscopy with Raman scattering we have investigated the mechanism of nanocrystal formation in ultrathin amorphous Si02/Ge/Si02 trilayers grown by e-beam evaporation as a function of annealing temperature and a-Ge layer thickness. We observe that with decreasing a-Ge thickness the amorphous-to-crystalline (a-to-c) transition occurs at considerably higher temperatures, even avoiding crystallisation for very thin films below 2 nm thickness. Furthermore, we demonstrate that the formation of Ge nano-crystals by annealing at around 900 °C takes place driven by a liquid-mediated mechanism. As indicated by the observed microstructure, the metallic liquid film dewets from the surface forming droplets that upon cooling and under the influence of the Si02 capping layer, solidify into barrel-type nanocrystals.

Original languageEnglish
Pages (from-to)3013-3019
Number of pages7
JournalJournal of Nanoscience and Nanotechnology
Volume9
Issue number5
DOIs
Publication statusPublished - May 2009

Fingerprint

Germanium
Crystallization
Nanoparticles
Nanocrystals
germanium
Annealing
crystallization
Thin films
Metallic films
Scanning Transmission Electron Microscopy
Temperature
Raman Spectrum Analysis
nanocrystals
Liquid films
thin films
Raman scattering
Evaporation
annealing
liquids
Crystalline materials

Keywords

  • Crystallisation
  • Dewetting
  • Embedded films
  • Ge nanocrystals
  • Raman scattering.

ASJC Scopus subject areas

  • Condensed Matter Physics
  • Chemistry(all)
  • Materials Science(all)
  • Bioengineering
  • Biomedical Engineering

Cite this

Garcia, G., Lopeandia, A. F., Bernardi, A., Alonso, M. I., Goni, A. R., Lábár, J., & Rodrfguez-Viejo, J. (2009). Crystallisation of amorphous germanium thin films. Journal of Nanoscience and Nanotechnology, 9(5), 3013-3019. https://doi.org/10.1166/jnn.2009.225

Crystallisation of amorphous germanium thin films. / Garcia, G.; Lopeandia, A. F.; Bernardi, A.; Alonso, M. I.; Goni, A. R.; Lábár, J.; Rodrfguez-Viejo, J.

In: Journal of Nanoscience and Nanotechnology, Vol. 9, No. 5, 05.2009, p. 3013-3019.

Research output: Contribution to journalArticle

Garcia, G, Lopeandia, AF, Bernardi, A, Alonso, MI, Goni, AR, Lábár, J & Rodrfguez-Viejo, J 2009, 'Crystallisation of amorphous germanium thin films', Journal of Nanoscience and Nanotechnology, vol. 9, no. 5, pp. 3013-3019. https://doi.org/10.1166/jnn.2009.225
Garcia, G. ; Lopeandia, A. F. ; Bernardi, A. ; Alonso, M. I. ; Goni, A. R. ; Lábár, J. ; Rodrfguez-Viejo, J. / Crystallisation of amorphous germanium thin films. In: Journal of Nanoscience and Nanotechnology. 2009 ; Vol. 9, No. 5. pp. 3013-3019.
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