Optical characterization using ellipsometry of Si nanocrystal thin layers embedded in silicon oxide

E. Agocs, P. Petrik, M. Fried, A. G. Nassiopoulou

Research output: Conference contribution

3 Citations (Scopus)

Abstract

We have developed optical models for the characterization of grain size in nanocrystal thin films embedded in SiO 2 and fabricated using low pressure chemical vapor deposition of Si from silane on a quartz substrate, followed by thermal oxidation. The as-grown nanocrystals thin film on quartz was composed of a two-dimensional array of Si nanocrystals (Si-NC) showing columnar structure in the z-direction and touching each other in the x-y plane. The nanocrystal size in the z-direction was equal to the Si nanocrystal film thickness, changing by the deposition time, while their x-y size was almost equal in all the samples, with small size dispersion. After high temperature thermal oxidation, a thin silicon oxide film was formed on top of the nanocrystals layer. The aim of this work was to measure the grain size and the nanocrystallinity of the Si nanocrystal thin films, a quantity related to the change of the dielectric function. We used a definition for the nanorcystallinity that is related to the effective medium analysis (EMA) of the material. The optical technique used for the investigations was spectroscopic ellipsometry. To measure the above sample properties the thickness and composition of several layers on a quartz substrate had to be determined by proper modeling of this complex system. We found that the nanocrystallinity (defined as the ratio of nc-Si/(c-Si+nc-Si) decreases systematically with increasing the Si-NC layer thickness. Using this approach we are sensitive to the lifetime broadening of electrons caused by the scattering on the grain boundaries, and not to the shift of the direct interband transition energies due to quantum confinement.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium Proceedings
Pages367-372
Number of pages6
Volume1321
DOIs
Publication statusPublished - 2012
Event2011 MRS Spring Meeting - San Francisco, CA, United States
Duration: ápr. 25 2011ápr. 29 2011

Other

Other2011 MRS Spring Meeting
CountryUnited States
CitySan Francisco, CA
Period4/25/114/29/11

Fingerprint

Silicon oxides
Ellipsometry
silicon oxides
Nanocrystals
ellipsometry
nanocrystals
Quartz
quartz
Thin films
thin films
grain size
Silanes
Low pressure chemical vapor deposition
Oxidation
oxidation
Quantum confinement
Spectroscopic ellipsometry
Substrates
complex systems
silanes

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

Cite this

Agocs, E., Petrik, P., Fried, M., & Nassiopoulou, A. G. (2012). Optical characterization using ellipsometry of Si nanocrystal thin layers embedded in silicon oxide. In Materials Research Society Symposium Proceedings (Vol. 1321, pp. 367-372) https://doi.org/10.1557/opl.2011.949

Optical characterization using ellipsometry of Si nanocrystal thin layers embedded in silicon oxide. / Agocs, E.; Petrik, P.; Fried, M.; Nassiopoulou, A. G.

Materials Research Society Symposium Proceedings. Vol. 1321 2012. p. 367-372.

Research output: Conference contribution

Agocs, E, Petrik, P, Fried, M & Nassiopoulou, AG 2012, Optical characterization using ellipsometry of Si nanocrystal thin layers embedded in silicon oxide. in Materials Research Society Symposium Proceedings. vol. 1321, pp. 367-372, 2011 MRS Spring Meeting, San Francisco, CA, United States, 4/25/11. https://doi.org/10.1557/opl.2011.949
Agocs E, Petrik P, Fried M, Nassiopoulou AG. Optical characterization using ellipsometry of Si nanocrystal thin layers embedded in silicon oxide. In Materials Research Society Symposium Proceedings. Vol. 1321. 2012. p. 367-372 https://doi.org/10.1557/opl.2011.949
Agocs, E. ; Petrik, P. ; Fried, M. ; Nassiopoulou, A. G. / Optical characterization using ellipsometry of Si nanocrystal thin layers embedded in silicon oxide. Materials Research Society Symposium Proceedings. Vol. 1321 2012. pp. 367-372
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