Full energy partitioning in 2 μm wavelength laser driven extreme ultraviolet sources

State-of-the-art nanolithography uses extreme ultraviolet (EUV) radiation at 13.5 nm emitted from tin laser-produced plasma (LPP), driven by a 10.6 µm wavelength CO2-gas laser, to create the smallest features on semiconductor devices. Advances in solid-state laser technologies have led to the alternative concept of a 2-µm-wavelength-driven LPP as a promising candidate for a more efficient and more powerful EUV source. We present the complete energy partitioning for a 2 µm wavelength-driven LPP, reconstructing the full input laser energy. With ∼70 %, most of the energy goes into photons, the largest part of which is emitted in the 5–80 nm wavelength range. Plasma ions contribute ∼30 % of the energy, and we find that this fraction decreases as a function of the laser intensity, a key insight in finding pathways to optimize plasma for industrial application. Our results offer insight into the energy partitioning of EUV-emitting plasmas for research and industrial nanolithography alike, and provide a benchmark for plasma light source development. Extreme ultraviolet sources for nanolithography use radiation generated from laser-produced tin plasma, where plasmas driven by 2 μm solid-state lasers have emerged as a possible concept for next-generation sources. The authors characterize the full power partitioning in a 2 μm laser-driven plasma, identifying the major contributions of radiative (~70 %) and ionic emissions (~30 %) and providing key insights for plasma light source development.