Abstract
An experimental study of laser-produced plasmas is performed by irradiating a planar tin target by laser pulses, of 4.8 ns duration, produced from a KTP-based 2-µm-wavelength master oscillator power amplifier. Comparative spectroscopic investigations are performed for plasmas driven by 1-µm- and 2-µm-wavelength pulsed lasers, over a wide range of laser intensities spanning 0.5 − 5 × 1011 W/cm 2. Similar extreme ultraviolet (EUV) spectra in the 5.5-25.5 nm wavelength range and underlying plasma ionicities are obtained when the intensity ratio is kept fixed at I1µm/I2µm = 2.4(7). Crucially, the conversion efficiency (CE) of 2-µm-laser energy into radiation within a 2% bandwidth centered at 13.5 nm relevant for industrial applications is found to be a factor of two larger, at a 60 degree observation angle, than in the case of the denser 1-µm-laser-driven plasma. Our findings regarding the scaling of the optimum laser intensity for efficient EUV generation and CE with drive laser wavelength are extended to other laser wavelengths using available literature data.
Original language | English |
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Pages (from-to) | 4475-4487 |
Number of pages | 13 |
Journal | Optics Express |
Volume | 29 |
Issue number | 3 |
Early online date | 28 Jan 2021 |
DOIs | |
Publication status | Published - 1 Feb 2021 |
Bibliographical note
Funding Information:Acknowledgements. 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), the Netherlands Organisation for Scientific Research (NWO) and the semiconductor equipment manufacturer ASML. The used transmission grating spectrometer has been developed in the Industrial Focus Group XUV Optics at University of Twente, and supported by the FOM Valorisation Prize 2011 awarded to F. Bijkerk and NanoNextNL Valorization Grant awarded to M. Bayraktar in 2015.
Funding Information:
Stichting voor de Technische Wetenschappen (15697); European Research Council (802648).
Publisher Copyright:
© 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Copyright:
Copyright 2021 Elsevier B.V., All rights reserved.
Funding
Acknowledgements. 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), the Netherlands Organisation for Scientific Research (NWO) and the semiconductor equipment manufacturer ASML. The used transmission grating spectrometer has been developed in the Industrial Focus Group XUV Optics at University of Twente, and supported by the FOM Valorisation Prize 2011 awarded to F. Bijkerk and NanoNextNL Valorization Grant awarded to M. Bayraktar in 2015. Stichting voor de Technische Wetenschappen (15697); European Research Council (802648).
Funders | Funder number |
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Horizon 2020 Framework Programme | 802648 |
European Research Council | |
Stichting voor Fundamenteel Onderzoek der Materie | |
Universiteit van Amsterdam | |
Nederlandse Organisatie voor Wetenschappelijk Onderzoek | |
Stichting voor de Technische Wetenschappen | 15697 |