Measurement of Roughness of Two Interfaces of a Dielectric Film by Scattering Ellipsometry

The polarization of light scattered by oxide films thermally grown on photolithographically generated microrough silicon surfaces was measured as functions of scattering angle. Using the predictions of first-order vector perturbation theory for scattering from interfacial roughness to interpret the results, the roughness of each interface and the correlation function between the two interfaces can be determined. The results show the spatial frequency dependence of the $\mathrm{SiO}{}_2/\mathrm{Si}$ interface smoothening.