The Materials and Surface Science for EUV Lithography group focuses on understanding the elementary physical and chemical processes occurring at surfaces relevant to nanolithography. Using near-ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS) in environments close to application conditions, we strive to identify the critical processes limiting the long-term performance and surface stability of essential components for EUV lithography, such as reflective multilayer structures for EUV mirrors. The identification of degradation pathways will allow us to explore new compounds and materials concepts for future components designed to withstand the challenging conditions of EUV lithography.