The project will engage with many participants, key stakeholders, and leading experts in order to develop a database with tailored optical materials and improved semiconductor manufacturing processes. Furthermore, extensive datasets from the planned three case studies will be provided.

•    The first case study will deal with onset of quantum effects and anisotropies for decreasing layer thicknesses.
•    The second case study will examine the influence of the measurement accuracy of optical constants on the reconstruction results of nanostructures.
•    The third case study will explore the dependence of optical constants for ultra-thin single layers and layer systems.

The database for optical constants and the provision of datasets from the case studies will enable end users to access reliable optical constants with their uncertainties, which are necessary for the development of modern functional optical materials.
The guideline on traceable reflectometry, Mueller ellipsometry and scatterometry, as reliable and traceable thin-film metrology technique, that would be developed in the project, would also help the end-users to improve their standard measurement techniques even further, and even pave the way for innovative optical coatings, such as in lithography masks.
Impact on the metrology and scientific committees
Measurement uncertainty, reliability and traceability are core issues in metrology. Indirect methods which require advanced modelling to solve an inverse problem are not yet standardised, which is a prominent issue for the determination of optical constants. The project will meet this challenge by establishing reliable uncertainties and traceability for reflectometry, Mueller ellipsometry and scatterometry. For this purpose, a complete uncertainty budget for the measurement methods will be set up and specific error models will be developed to deal with errors in modelling. Modern statistical methods such as Bayesian optimisation will be utilised thus extending the usability of the results beyond optical metrology.

Measurement uncertainty, reliability and traceability are core issues in metrology. Indirect methods which require advanced modelling to solve an inverse problem are not yet standardised, which is a prominent issue for the determination of optical constants. The project will meet this challenge by establishing reliable uncertainties and traceability for reflectometry, Mueller ellipsometry and scatterometry. For this purpose, a complete uncertainty budget for the measurement methods will be set up and specific error models will be developed to deal with errors in modelling. Modern statistical methods such as Bayesian optimisation will be utilised thus extending the usability of the results beyond optical metrology.