Ellipsometers are widely used in various fields, including semiconductors and displays. Since it measures the film thickness and optical constants (refractive index and extinction coefficient) of transparent or translucent thin films (Oxide film, nitride film, resist, ITO) deposited on Si or glass substrates, it is used for resist film distribution in the lithography field of semiconductor field, and it is also used for organic film evaluation of organic EL panels in display field.
Ellipsometry (polarization analysis) is used to analyze film thickness and optical constants of thin film from changes in the polarization state of light.When light with a certain polarization state is incident on the sample surface, the phase and amplitude of the incident light change by a thin film becomes the composite light reflecting from the film surface and the substrate surface. This phase change is called delta (Δ) and the amplitude ratio is called psi (ψ).The ellipsometer measures these two to obtain film thickness and refractive index.
