Structural Properties of Si Nanoclusters Produced by Thermal Annealing of SiOx Films

The structural properties of Si nanoclusters embedded in SiO2, produced by high temperature annealing of SiOx films, have been investigated by energy filtered transmission electron microscopy. The presence of amorphous nanostructures, not detectable by using dark field transmission electron microscopy, has been demonstrated. By taking into account also this contribution, a quantitative description of the evolution of the samples upon thermal annealing has been accomplished. In particular, the nanocluster mean radius and the density of amorphous and crystalline clusters have been determined as a function of the annealing temperature.