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.

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.

A design for a metallic thermal protection system (TPS) panel made of SS304 stainless steel was developed to withstand a simulated aerodynamic heating rate of [Formula: see text]. The TPS panel, which comprised an outer sandwich structure, thermal insulation material, stand-off brackets, and an interior base frame, faced challenges from its thermomechanical and impact properties. These challenges were addressed through a combined analytical and numerical approach, optimizing the design parameters, namely, deflection, low-velocity impact peak load, and weight balance, to enhance the performance of the sandwich structure. The results indicated consistency between the analytical and numerical models, effectively predicting deflection and initial peak load for the TPS design. The proposed TPS design was then manufactured and evaluated through both experimental and numerical analysis to assess its thermomechanical behavior. The underlying structure of the TPS panel remained within specified temperature limits, and the exterior sandwich structure demonstrated acceptable levels of impact energy. The experiment confirmed the feasibility of the TPS panel design, with no significant damage observed after 10 simulated flight missions. This study not only validates the proposed analytical method for initial TPS development stages but also confirms the viability of a SS304 stainless-steel TPS panel design for high thermal-stress environments, marking a significant step in advancing thermal protection technology.

During the high-speed flight of a vehicle in the atmosphere, surface friction with the air generates aerodynamic heating. The aerodynamic heating phenomenon can create extremely high temperatures near the surface. These high temperatures impact material properties and the structure of the aircraft, so thermal deformation measurement is essential in aerospace engineering. This paper revisits high-temperature deformation measurement using the digital image correlation (DIC) technique under high-intensity blackbody radiation with a precise speckle pattern fabrication and a heat haze reduction method. The effect of speckle pattern on the DIC measurement has been thoroughly studied at room temperature, but high-temperature measurement studies have not reported such effects so far. We found that the commonly used methods to reduce the heat haze effect could produce incorrect results. Hence, we propose a new method to mitigate heat haze effects. An infrared radiation heater was employed to make an experimental setup that could heat a specimen up to 950 ℃. First, we mitigated image saturation using a short-wavelength bandpass filter with blue light illumination, a standard procedure for high-temperature DIC deformation measurement. Second, we studied how to determine the proper size of the speckle pattern under a high-temperature environment. Third, we devised a reduction method for the heat haze effect. As proof of the effectiveness of our developed experimental method, we successfully measured the deformation of stainless steel 304 specimens from 25 ℃ to 800 ℃. The results confirmed that this method can be applied to the research and development of thermal protection systems in the aerospace field.

During the high-speed flight of a vehicle in the atmosphere, surface friction with the air generates aerodynamic heating. The aerodynamic heating phenomenon can create extremely high temperatures near the surface. These high temperatures impact material properties and the structure of the aircraft, so thermal deformation measurement is essential in aerospace engineering. This paper revisits high-temperature deformation measurement using the digital image correlation (DIC) technique under high-intensity blackbody radiation with a precise speckle pattern fabrication and a heat haze reduction method. The effects of the speckle pattern on the DIC measurement have been thoroughly studied at room temperature, but high-temperature measurement studies have not reported such effects so far. We found that the commonly used methods to reduce the heat haze effect could produce incorrect results. Hence, we propose a new method to mitigate heat haze effects. An infrared radiation heater was employed to make an experimental setup that could heat a specimen up to 950 °C. First, we mitigated image saturation using a short-wavelength bandpass filter with blue light illumination, a standard procedure for high-temperature DIC deformation measurement. Second, we studied how to determine the proper size of the speckle pattern in a high-temperature environment. Third, we devised a reduction method for the heat haze effect. As proof of the effectiveness of our developed experimental method, we successfully measured the deformation of stainless steel 304 specimens from 25 °C to 800 °C. The results confirmed that this method can be applied to the research and development of thermal protection systems in the aerospace field.