The mechanisms associated with Si/SiO2 interface annealing and thermal oxidation conditions were studied by spectroscopic immersion ellipsometry. Essentially, this surface sensitive ellipsometry technique uses liquids that match the refractive index of the films, thereby optically removing the films.
With the use of an optical model, it is shown that at high annealing temperatures viscous relaxation dominates, while at low annealing temperatures the suboxide reduction is apparent. It is also shown that with the thickening SiO2 overlayer, the thickness of the suboxide layer at the interface increases and the average radius of the crystalline silicon protrusions decreases for the three different orientation studied. These results are consistent with the commonly accepted Si oxidation model.