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arXiv · 2605.21430

Holographic EUV Lithography at 40 nm Resolution

Ziqi Li·Iason Giannopoulos·Lisong Dong·Dimitrios Kazazis·Xu Ma·Zongqiang Yu·Zhiyuan Niu·Yasin Ekinci·Yayi Wei·Iacopo Mochi
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Abstract

Extreme ultraviolet (EUV) lithography is the cornerstone of the fabrication of advanced integrated circuits at the 7-nm node and beyond, but its reliance on multi-element reflective projection optics makes it inaccessible for small-scale research and prototyping. EUV interference lithography (EUV-IL) provides a lensless alternative but is intrinsically restricted to periodic structures. Here we demonstrate EUV holographic lithography (EUV-HL) as a lensless route to arbitrary, non-periodic, curvilinear patterning at the EUV wavelength of 13.5 nm. We introduce an inverse-design framework for computer-generated holograms that captures the dominant physical effects of EUV mask diffraction within a shift-invariant convolution model that is tractable for full mask layouts. Using this framework, we design and fabricate transmissive holographic masks by direct-write electron-beam lithography in hydrogen silsesquioxane, expose them with synchrotron-generated EUV radiation, and print target layouts with critical dimensions down to 40 nm, nearly an order of magnitude finer than the previous state of the art in EUV-HL. The demonstrated combination of sub-50 nm resolution, curvilinear design freedom, and a lensless optical setup establishes EUV-HL as a uniquely flexible tool for nanostructure prototyping at EUV wavelengths, and provides a natural pathway to non-periodic pattern prototyping at beyond-EUV (BEUV) wavelengths, which is currently inaccessible to interference-based methods.

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Ziqi Li, Iason Giannopoulos, Lisong Dong, Dimitrios Kazazis, Xu Ma, Zongqiang Yu, Zhiyuan Niu, Yasin Ekinci, Yayi Wei, Iacopo Mochi. 2026-05-20. Holographic EUV Lithography at 40 nm Resolution. https://arxiv.org/abs/2605.21430

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