EUV reticle defectivity: next steps in the EUV scanner and beyond

Abstract

Since the introduction of EUV, ASML and its industry partners have continuously improved the reticle defectivity levels in the volume manufacturing flows. In this paper we will show the progress over the years in reticle defectivity performance and what was done to achieve this. Next, an outlook of the defectivity improvements of the next product, NXE:3800 will be given. Finally, on the longer term, it will be shown how defectivity mitigation will be developed in the future platforms. In detail, these future developments extend the defect mitigations from the current cleanliness and flow optimizations further into the electrostatic realm. An overview will be given of the improvements planned in the EUV scanner, and the necessary changes needed on the EUV reticle infrastructure to fully benefit from these improvements. With all changes implemented it will be shown that electrostatic particle control can achieve a reticle defectivity reduction by more than 50%.