Prominent radiative contributions from multiply-excited states in laser-produced tin plasma for nanolithography

F. Torretti, J. Sheil, R. Schupp, M. M. Basko, M. Bayraktar, R. A. Meijer, S. Witte, W. Ubachs, R. Hoekstra, O. O. Versolato*, A. J. Neukirch, J. Colgan

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review


Extreme ultraviolet (EUV) lithography is currently entering high-volume manufacturing to enable the continued miniaturization of semiconductor devices. The required EUV light, at 13.5 nm wavelength, is produced in a hot and dense laser-driven tin plasma. The atomic origins of this light are demonstrably poorly understood. Here we calculate detailed tin opacity spectra using the Los Alamos atomic physics suite ATOMIC and validate these calculations with experimental comparisons. Our key finding is that EUV light largely originates from transitions between multiply-excited states, and not from the singly-excited states decaying to the ground state as is the current paradigm. Moreover, we find that transitions between these multiply-excited states also contribute in the same narrow window around 13.5 nm as those originating from singly-excited states, and this striking property holds over a wide range of charge states. We thus reveal the doubly magic behavior of tin and the origins of the EUV light.

Original languageEnglish
Article number2334
Pages (from-to)1-8
Number of pages8
JournalNature Communications
Issue number1
Early online date11 May 2020
Publication statusPublished - 1 Dec 2020


We thank J. Abdallah, C.J. Fontes, H.A. Scott, Y.R. Frank and J.W.M. Frenken for useful discussions. This project has received funding from European Research Council (ERC) Starting Grant number 802648 and is part of the VIDI research programme with project number 15697, which is financed by the Netherlands Organization for Scientific Research (NWO). Part of this work has been carried out at the Advanced Research Center for Nanolithography (ARCNL), a public-private partnership of the University of Amsterdam (UvA), the Vrije Universiteit Amsterdam (VU), NWO and the semiconductor equipment manufacturer ASML. Part of this work was supported by the Physics & Engineering Materials (PEM) program of the US Department of Energy through the Los Alamos National Laboratory. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of U.S. Department of Energy (Contract No. 89233218NCA000001). The spectrometer has been supported by the FOM Valorisation Prize 2011 awarded to F. Bijkerk and NanoNextNL Valorization Grant awarded to M. Bayraktar in 2015.

FundersFunder number
Netherlands Organization for Scientific Research
US Department of Energy
U.S. Department of Energy89233218NCA000001
National Nuclear Security Administration
Los Alamos National Laboratory
Horizon 2020 Framework Programme802648
European Research Council15697
Nederlandse Organisatie voor Wetenschappelijk Onderzoek
Foundation for Fundamental Research on Matter


    Dive into the research topics of 'Prominent radiative contributions from multiply-excited states in laser-produced tin plasma for nanolithography'. Together they form a unique fingerprint.

    Cite this