Etude par ellipsométrie spectroscopique des effets de taille sur les propriétés optiques de couches composites à matrice diélectrique et du silicium nanostructuré

Abstract : Thin composite films containing Si nanocrystals within a dielectric matrix may have several potential applications such as in nanoelectronics for the design of memory devices or in optoelectronics in view of the implementation of high-efficiency solar cells or the development of a silicon-based laser. Initially, we used spectroscopic ellipsometry in order to describe the optical properties of silicon-rich silicon nitride films (SRSN), mainly produced by chemical vapor deposition and thereafter subjected to rapid thermal annealing (RTA). We showed that the presence of Si nanoparticles (Si-NPs), that are observable by transmission electron microscopy, can be predicted by using a purely optical criterion. The RTA annealing leads to the formation of high densities of Si nanoparticles in the composite films. The optical properties of the Si-NPs have been calculated by three different methods: wavelength-by-wavelength numerical inversion (without any fitting parameters). The evolution of the parameters of this latter formula reveals the presence of confined amorphous Si-NPs in the investigated samples. We also highlighted the role of the flows ratio of the precursor gases RQ (=QNH3/QSiH4) and the annealing temperature TR on the optical properties of both the films and the Si-NPs they contain. Indeed a slight increase in RQ induced a significant variation in the spectrum of the dielectric function of the Si-NPs. On the other hand, the influence of the annealing temperature is noticeable beyond 950°C, and results in an increase of the amplitude and a reduction of the broadening of the...
Complete list of metadatas

Cited literature [186 references]  Display  Hide  Download

https://hal.univ-lorraine.fr/tel-01749218
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 12:09:50 PM
Last modification on : Monday, April 16, 2018 - 10:43:11 AM
Long-term archiving on: Friday, September 14, 2018 - 9:50:16 AM

File

DDOC_T_2012_0051_KEITA.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : tel-01749218, version 1

Collections

Citation

Al-Saleh Keita. Etude par ellipsométrie spectroscopique des effets de taille sur les propriétés optiques de couches composites à matrice diélectrique et du silicium nanostructuré. Autre [cond-mat.other]. Université de Lorraine, 2012. Français. ⟨NNT : 2012LORR0051⟩. ⟨tel-01749218⟩

Share

Metrics

Record views

50

Files downloads

403