Ellipsometric study of crystallization of amorphous Ge thin films embedded in SiO2

M. I. Alonso, M. Garriga, A. Bernardi, A. R. Goñi, A. F. Lopeandia, G. Garcia, J. Rodríguez-Viejo, J. L. Lábár

Research output: Article

10 Citations (Scopus)

Abstract

We use spectroscopic ellipsometry to investigate crystallization of amorphous Ge thin films by thermal annealing of SiO2/a-Ge/SiO2 trilayer structures. We study the influence of both film thickness and annealing temperature on the effective dielectric functions of the Ge films, which are related to the film micro- and nanostructures. For annealing temperatures below 900 °C, all films remain continuous and consist of mixtures of amorphous and nanocrystallized Ge. The crystallite sizes can be estimated from the observed energy blueshift of the E1 interband transition. Samples annealed at 900 °C display dielectric function spectra which differ from a bulk-like behavior. This suggests a variation in optical properties which is correlated to formation of discontinuous films of Ge nanocrystals.

Original languageEnglish
Pages (from-to)4277-4281
Number of pages5
JournalThin Solid Films
Volume516
Issue number12
DOIs
Publication statusPublished - ápr. 30 2008

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Surfaces and Interfaces
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Materials Chemistry

Cite this

Alonso, M. I., Garriga, M., Bernardi, A., Goñi, A. R., Lopeandia, A. F., Garcia, G., Rodríguez-Viejo, J., & Lábár, J. L. (2008). Ellipsometric study of crystallization of amorphous Ge thin films embedded in SiO2. Thin Solid Films, 516(12), 4277-4281. https://doi.org/10.1016/j.tsf.2008.01.003