Multilayered Composite Membranes Based on Layer‐by‐Layer Stacked Graphene Films for Ultraviolet Pellicle Applications

Abstract Graphene is a promising material for next‐generation extreme ultraviolet (EUV) pellicles due to its excellent optical transparency, mechanical, and thermal stability under intense EUV radiation. However, challenges remain in precisely controlling its thickness at large scales and preventing hydrogen radical‐induced degradation. In this study, a multilayer graphene composite with protective capping layers, enabling nanometer‐scale thickness control is devloped. A 10‐layer, 5 nm thick graphene film achieves ≈92% transparency and an effective Young's modulus of 220 GPa. When integrated into a free‐standing molybdenum (Mo)/graphene/silicon nitride (SiN) composite, the Young's modulus increases by 29%, and the fracture load improves by 840% compared to a single‐layer SiN membrane. Molecular dynamics simulations confirm that the enhanced mechanical strength mainly results from graphene's intrinsic properties. Additionally, a full‐size pellicle with five graphene layers and a 100 nm SiN layer are fabricated, which maintains over 90% EUV transparency on a 7 nm SiN substrate. These results suggest that multilayer graphene membranes can overcome current EUV pellicle limitations and support the broader commercialization of EUV lithography in the near future.