Crystallisation of amorphous germanium thin films

G. Garcia, A. F. Lopeandia, A. Bernardi, M. I. Alonso, A. R. Goni, J. L. Labar, 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 1 2009

Keywords

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

ASJC Scopus subject areas

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

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  • Cite this

    Garcia, G., Lopeandia, A. F., Bernardi, A., Alonso, M. I., Goni, A. R., Labar, J. L., & 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