Silicon nanocrystals precipitation in a SiO2 matrix elaborated from the decomposition of LPCVD SiOx

In this paper, we present results of a study which aims to obtain silicon nanocrystals (Si_nc) embedded in a thin SiO₂ matrix, using high temperature annealing, from the thermal decomposition of SiO_x. So, thin SiO_x films (4-10 nm) are grown from a N₂O/SiH₄ mixture in an industrial LPCVD reactor with different process parameters. Spectroscopic ellipsometry and Fourier transform infrared spectroscopy are used both to determine the stoichiometry of the SO_x and the decomposition state of the film after high temperature annealing. X-ray photoelectron spectroscopy confirms the completion of the reaction after annealing at 1000°C for 15 minutes and transmission electron microscopy shows that the crystallinity of the silicon dots is dependent both on the stoichiometry of the SiO_x film and on the annealing temperature. Finally, some electrical results are presented and they show charge trapping in the SiO_x LPCVD layer.