Structural analysis of the interface of silicon nanocrystals embedded in a Si3N4 matrix
Résumé
The structure and interface states of thin nanocomposite layers containing Si nanocrystals embedded in an amorphous nitride matrix have been analyzed by Raman spectroscopy and x-ray photoelectron spectroscopy (XPS). The Si 2p core-level spectrum of the nanocomposite layer was deconvoluted by using five Gaussian-Lorentzian contributions corresponding to the different nitride states of Si. It was shown that the Si-ncs/Si3N4 interfaces formed during annealing are composed of a high density of Si2+ subnitrides. These subnitrides are more likely to be responsible for the shoulder at 494cm-1 on the Raman spectra. Considering the proportion of Si2+ subnitrides with respect to Si0 states, an abrupt transition from the crystalline to the amorphous phase due to Si 2=N-Si bridge bonds is suggested.
Mots clés
Interfaces (materials)
Nanocomposites
Nitrides
Plasma enhanced chemical vapor deposition
Raman spectroscopy
Silicon
X ray photoelectron spectroscopy
Abrupt transition
Amorphous phase
Core-level spectra
Nano-composite layers
Nitride matrix
Pulsed Plasma Enhanced Chemical Vapor Deposition
Si nanocrystal
Silicon nanocrystals
Amorphous silicon