Multilayered EUV pellicle: enhanced mechanical strength and thermal stability

Extreme-ultraviolet (EUV) lithography is a critical technology for producing the finest patterns in semiconductor manufacturing, and the development of reliable EUV pellicle is crucial to prevent mask contamination and ensuring pattern quality. However, achieving stability over 5000 wafer exposures with more than 90% EUV transmittance in thin film is challenging. Although research on porous pellicles using carbon nanotubes (CNTs) is being ongoing, these materials still face difficulties with durability in hydrogen radical environments. To address these issues, we present a multilayer structure that enhances EUV transmittance while also improving thermo-mechanical stability. Our findings demonstrate that stacking layers of MoSi2/Si pellicle can improve the ultimate tensile strength (UTS), achieving 2.1 GPa compared to the single layered MoSi₂ pellicle targeting the same EUVT of 90%. Meanwhile, although the MoSi₂/Si multilayer structure consists of thinner emission layers, minimal loss of emissivity was confirmed due to the cumulative contribution of emission from each stacked layer.