A fully automatized method for the unambiguous wavelength-by-wavelength determination of the thickness and optical property of a very thin film with a transparent range

Spectroscopic ellipsometry is a powerful method with high surface sensitivity that can be used to monitor the growth of even sub-monolayer films. However, analysis ultrathin films complicated by correlation between dielectric constant and thickness. This problem usually resolved fixing one or other value, limiting information extracted. Here, we propose determine unambiguously refractive index, extinction coefficient, thickness film when transparent range available in energy investigated. We decompose three steps. First, determined from film. Then, knowing layer, an initial estimation index coefficient made based on first-order Taylor expansion ellipsometric ratio. Finally, using this estimation, numerical iteration done ensure convergence fit toward solution. A theoretical example given for two different thicknesses TiO2 applied experimental data measured during atomic layer deposition thin Hf0.5Zr0.5O2 grown Si. The thickness, are retrieved precision (respectively, 0.01 0.002) 3.5–6.5 eV. detailed presented accuracy values their dependency random systematic errors ranges.