Full field EUV lithography turning into a reality at IMEC

A research program on EUV lithography has been started at IMEC, based on ASMLs EUV full field scanner, the Alpha Demo Tool (ADT). It contains three main projects: EUV resists, EUV reticles and assessment of the ADT performance. The intent of this program is to help improve and establish the necessary mask and resist infrastructure, and achieve learning to prepare for the use of EUV lithography in future production of integrated circuits. Good progress in resist performance, as assessed by interference lithography, is illustrated by the ability of some materials to resolve 25nm HP. In its initial phase, the reticle project has concentrated on working with the mask and blank suppliers to assure timely availability of reticles for the ADT. An overview is given of the other reticle related activities, as well as first results of a defect printability assessment by simulation and a study of blank reflectivity control. Guidance is given to the EUV mask infrastructure to assure timely availability of reticles, first for the alpha demo tool (ADT), but also in preparation for future use of EUV lithography in production. In the ADT assessment project, simulation studies are reported aimed at the development of optical correction for flare and reticle shadowing effects. The impact of flare and shadowing effects are well understood Strategies for flare mitigation and shadowing effect correction are proposed.

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