SILICON CLUSTERS IN SILICON MONOXIDE FILMS

In this paper, results of ellipsometric, XRD and TEM studies on evaporated and thermally annealed thin SiOx films are presented. The thickness of the films was determined from the ellipsometric measurements and checked by TEM pictures taken in cross-section mode. The composition of the SiOx films was estimated by applying different models to simulate the ellipsometric data. It has been shown that annealing at 700 oC leads to appearance of amorphous Si clusters. The Si nanoclusters in crystalline phase were found only after annealing at 1000 oC. By X-ray scattering measurements, only one crystalline peak is detected, mirroring the (100) orientation of the Si substrate, which suggests that the size of Si nanocrystallites is too small to be observed with XRD, or their volume fraction is too low. The TEM images have proven the presence of crystallized Si clusters in the oxide matrix being randomly distributed and sized between 1- 4 nm. The ellipsometric modeling results are in good agreement with the XRD and TEM observations, as they detect crystalline Si inclusions at 1000 oC with a volume fraction less than 12 %