2026-08-25 理化学研究所,宇都宮大学
マルチレーザー照射法の概念図
＜関連情報＞
- https://www.riken.jp/press/2026/20260825_1/index.html
- https://opg.optica.org/ol/abstract.cfm?uri=ol-51-17-4892
同時二光束2μmレーザー照射により極端紫外線変換効率が40%向上 40% boost in extreme ultraviolet conversion efficiency via simultaneous dual-beam 2-μm laser irradiation
Naoki Nagahama, Kaito Nishimiya, Shunya Yamamoto, Hayato Yazawa, Yuta Takai, Chisato Tanaka, Kazuyuki Sakaue, Atsushi Sunahara, Gerry O’Sullivan, Shinichi Namba, Takeshi Higashiguchi, and Eiji J. Takahashi
Optics Letters Published: August 24, 2026
DOI:https://doi.org/10.1364/OL.607856
Abstract
The upscaling of extreme ultraviolet (EUV) source power for next-generation lithography demands higher conversion efficiency (CE) at reduced per-pulse energies. We demonstrate a 40% EUV CE enhancement by simultaneous dual-beam irradiation of a planar Sn target with a 2090-nm, 20-ns Ho:YAG laser. Single-beam irradiation at 40 mJ yielded an EUV CE of 2.6%; splitting the same total energy equally into two beams of 20 mJ each, at identical peak intensity, raised the EUV CE to 3.6%, which is the highest, to the best of our knowledge, reported for 2-μm-driven laser-produced plasma sources by the Sn planar target. The EUV source size (60–70 μm) was nearly identical across both configurations. Because the scheme requires only passive beam splitting and scales readily to three or more beams, it offers a practical route toward multi-kW-class, energy-efficient EUV sources for high-NA and hyper-NA lithography.
