Si Nanocrystals Embedded in a Silicon Oxynitride Matrix

We investigated the morphological and structural change in silicon nanostructures embedded in the silicon oxynitride matrix. The study has been carried out on thin films thermally annealed at high temperature, after deposition at 400°C by Electron Cyclotron Resonance Plasma Enhanced Chemical Vapour Deposition (ECR- PECVD), under different deposition parameters. Our study evidenced the existence of a well defined threshold for the silicon content in the film (around 47%), to get Si nano-crystallization in the silicon oxynitride matrix. Both Si nano-crystals and Si nano-columns have been observed by TEM analysis in two samples having a similar Si content but deposited under different conditions.