Determination of the optical constants of the SiSiO2 system by the method of the angular modulation of reflectance

The sensitivity of the method of the angular modulation of reflectance, recently developed by the authors, in the determination of the optical constants of the SiSiO₂ system is analyzed. This system, which can be approximated to a TFAS system in the visible region, is considered in the limit of small relative thicknesses $\text{d}{}_{\mathrm{<mtext>ox</mtext>}}\text{λ}$. The method proved sufficiently accurate to give the refractive index of the substrate n_s as well as the parameters of the oxide n_ox and d_ox with an accuracy of 2 % down to $\text{d}{}_{\mathrm{<mtext>ox</mtext>}}\text{= 200}\text{A}\text{?}$. The overall accuracy increases at larger oxide thicknesses.