Dielectric functions of SiO2 film embedded with silicon nanocrystals

In this work, we report a non-destructive approach, which is based on the spectroscopic ellipsometry (SE) and a multi-layer model, to calculate the depth profiling of the dielectric functions of SiO2 films containing Si nanocrystals (nc-Si) synthesized by ion beam technique. Each sub-layer of SiO2 film containing nc-Si is represented by Maxwell-Garnett effective medium approximation (EMA). Then the nc-Si dielectric functions are extracted from the best fittings of SE results. Finally, the dielectric functions of each sub-layer of SiO2 containing nc-Si are calculated with Maxwell-Garnett EMA using the previously extracted information of nc-Si, and thus the depth profile of dielectric functions for the SiO2 thin film containing the nc-Si is obtained.