Spectroscopic ellipsometer is widely used for thin film analysis and measurements. Holmarc’s spectroscopic ellipsometer incorporates Rotating Analyzer Ellipsometry technology to characterize thin film samples. It uses a high speed CCD array detection to collect the entire spectrum. It measures films from nanometer thickness up to tens of microns and the optical properties from transparent to absorbing materials. It accurately measures optical constants like refractive index, film thickness and extinction coefficient.
Our standard system comes with Quartz-Halogen lamp from visible to IR range. Our spectroscopic ellipsometer software allows the user to measure and analyze multilayer thin films and complex thin film structures. An autocollimator, Z stage and tilt platforms are provided for sample alignment. XY motorized stage and motorized rotation stages are provided as an optional feature for mapping thin film uniformity.
Ellipsometry is a highly sensitive technique for thin film analysis. The principle relies on the changes in the polarization state of light when reflecting from a surface. To characterize the polarization state, corresponding to the direction of the electric filed of the electromagnetic wave; two directions are chosen as reference, p-direction (parallel) and sdirection (perpendicular). The reflected light has phase changes that are different for p-direction and s-direction. Ellipsometry measure this state of polarization;
p = rp / rs = tan ΨeiΔ
Where Ψ and Δ are the amplitude ratio and phase shift of the p and s components respectively. Since ellipsometry measures ratio of two values, it is very accurate and repeatable.