Accelerating Next-Generation EUV Lithography (ANGEL) through a co-design of laser-produced plasma sources and multilayer mirrors

Microelectronic manufacturing heavily relies on advancements in photolithography to create smaller features on semiconductor wafers. Currently, extreme ultraviolet lithography (EUVL) leads this innovation drive. At the heart of EUVL is the laser-produced plasma (LPP) source, which generates 13.5 nm photons by targeting a tin droplet with a laser, while multilayer mirrors (MLMs) direct these photons onto the wafer. A significant challenge for EUVL is to achieve throughput suitable for high-volume production, necessitating enhancements in LPP efficiency and mitigating MLM degradation under extreme conditions of Sn iron irradiation and secondary hydrogen plasma. The research ongoing in ANGEL funded by the department of energy microelectronic science research center, aims to understand EUV photon generation and optimize their transport in an LPP source, as well as explore and control MLM degradation due to EUV debris and hydrogen plasma. Accomplishing these goals will help develop high-power EUV sources with improved efficiency and durable EUV optical components. Our objectives include understanding Sn ion kinetics, radiative transfer, quantifying MLM degradation influences, and guiding MLM material improvements. We are employing state-of-the-art operando plasma diagnostics, coupled with collisional radiative plasma modeling, to understand parameters vital for EUV radiation transport. Machine-learning-driven experimental design will enhance LPP source efficiency. Integrating these findings with multiscale analysis and material degradation modeling will foster the design of robust EUV LPP sources and MLMs. The ANGEL project aims to offer deeper insights into LPP radiation transport and behavior during EUV generation and establish mechanisms for interaction between plasma species, the hydrogen process gas, and MLMs. Ultimately, successful research outcomes will support the demonstration of next-generation EUV sources, reducing EUVL system production costs, enhancing U.S. microelectronics manufacturing competitiveness.