What is ISO 23131 about?
ISO 23131 is about the principles of ellipsometry.
ISO 23131 specifies a method for determining optical and dielectric constants in the UV-VIS-NIR spectral range as well as layer thicknesses in the field of at-line production control, quality assurance, and material development through accredited test laboratories.
Ellipsometry is an indirect measuring method, the analysis of which is based on model optimization. The measurands, which differ according to the procedural principle, are converted into the ellipsometric factors Ψ (Psi, amplitude information) and Δ (Delta, phase information), based on which the physical target figures of interest (optical or dielectric constants, layer thicknesses) will then be determined by means of a parameterized fit.
Who is ISO 23131 for?
ISO 23131 on the principles of ellipsometry is beneficial for:
- Physicists
- People working for electromagnetic fields
- People who work for dielectric properties
- Researchers in disciplines such as biology and medicine
- Chemical engineers
Why should you use ISO 23131?
The ellipsometry measuring method is a phase-sensitive reflection technique using polarized light in the optical far-field. Over a long time, ellipsometry has been established as a non-invasive measuring method in the field of semiconductor technology — especially within the integrated production — in the first instance as a single-wavelength, then as a multiple-wavelength, and later as a spectroscopic measuring method. By means of ellipsometry, optical or dielectric constants of any material, as well as the layer thicknesses of at least semi-transparent layers or layer systems, can be determined.
ISO 23131 is beneficial for the user as ellipsometry shows a high precision regarding the ellipsometric transfer quantities Ψ and Δ, which can be equivalent to a layer thickness sensitivity of 0,1 nm for the ideal layer substrate systems. As a result, the measuring method can verify even the slightest discrepancies in the surface characteristics. ISO 23131 gives the absolute accuracy, e.g., of layer thickness values, substantially depending on the quality of the chosen model for describing the material surface. ISO 23131 is applicable to stand-alone measuring systems.
Overall, ISO 23131 is helpful as it provides details about ellipsometry and its principles which can be beneficial for the business of the user. Ellipsometry is a powerful procedure, which either enables material fingerprints (without modelling) or which allows a model-based determination of optical and dielectric constants (to the nearest 0,001) or of layer thicknesses (to the nearest 0,1 nm) within a broad layer thickness range of approximately 0,1 nm up to approximately 10 μm (in special cases exceeding 100 μm).