High-NA EUV Lithography exposure tool: program progress and mask impact (Conference Presentation)

While EUV systems equipped with a 0.33 Numerical Aperture (NA) lens are readying to start high volume manufacturing, ASML and ZEISS are in parallel ramping up their activities on an EUV exposure tool with an NA of 0.55. The purpose of this high-NA scanner, targeting a resolution of 8nm, is to extend Moore’s law throughout the next decade. A novel lens design, capable of providing the required Numerical Aperture, has been identified; this lens will be paired with new, faster stages and more accurate sensors enabling the tight focus and overlay control needed for future process nodes. In this paper an update will be given on the status of the developments at ZEISS and ASML. Next to this, we will address several topics concerning the interaction of the High-NA optics and its associated different magnifications on requirements for the mask, in particular defectivity, flatness, substrate thermal properties, novel absorbers, need for assist features, pellicle and stitching.