Oxidation of Si nanocrystals fabricated by ultralow-energy ion implantation in thin SiO2 layers

H. Coffin (1) , Caroline Bonafos (1) , Sylvie Schamm-Chardon (1) , Nikolay Cherkashin (2) , Gérard Benassayag (1) , Alain Claverie (2) , Marc Respaud (3) , P. Dimitrakis (4) , P. Normand (4)

1 CEMES - Centre d'élaboration de matériaux et d'études structurales
2 CEMES-MEM - Matériaux et dispositifs pour l'Electronique et le Magnétisme
3 LNMO - Laboratoire de Nanophysique Magnétisme et Optoélectronique
4 NCSR - National Center for Scientific Research "Demokritos"

The effect of thermal treatments in nitrogen-diluted oxygen on the structural characteristics of two-dimensional arrays of Si nanocrystals (NCs) fabricated by ultralow-energy ion implantation (1 keV) in thin silicon dioxide layers is reported. The NC characteristics (size, density, and coverage) have been measured by spatially resolved electron-energy-loss spectroscopy by using the spectrum-imaging mode of a scanning transmission electron microscope. Their evolution has been studied as a function of thermal treatment duration at a temperature (900 °C) below the SiO2 viscoelastic point. An extended spherical Deal-Grove [J. Appl. Phys. 36, 3770 (1965)] model for self-limiting oxidation of embedded silicon NCs has been carried out. It proposes that the stress effects, due to oxide deformation, slow down the NC oxidation rate and lead to a self-limiting oxide growth. The model predictions show a good agreement with the experimental results. Soft oxidation appears to be a powerful way for manipulating the NC size distribution and surface density.

Domaines: Science des matériaux [cond-mat.mtrl-sci]; Micro et nanotechnologies/Microélectronique

H. Coffin, Caroline Bonafos, Sylvie Schamm-Chardon, Nikolay Cherkashin, Gérard Benassayag, et al.. Oxidation of Si nanocrystals fabricated by ultralow-energy ion implantation in thin SiO2 layers . Journal of Applied Physics, 2006, 99 (4), pp.044302. ⟨10.1063/1.2171785⟩. ⟨hal-01736074⟩