Sub‐10‐nm Lithography for Sn4–Oxo Clusters: Effect of Molecular Polarity on Sensitivity and Resolution

Abstract Tin‐based metal–oxo clusters have recently garnered considerable attention in high‐energy irradiation lithography because of their nanoscale patterning capabilities. However, achieving sub‐10 nm resolution remains a challenge due to uncontrolled latent image gradients after exposure. In this study, the development mechanism of the Sn4–oxo cluster is investigated using a molecular polarity index model. Resolutions of 8 and 17 nm are successfully achieved for Sn4‐TF using electron beam lithography (EBL) and extreme ultraviolet lithography (EUVL), respectively. A novel ultraviolet pre‐irradiation modification strategy is proposed to enhance sensitivity by one‐third for both EBL and EUVL. The experimental findings and theoretical analysis demonstrate that deep ultraviolet (DUV) lithography primarily degrades organic ligands and promotes Sn–O–Sn crosslinking, whereas EBL and EUVL drive both Sn–O–Sn and hydrocarbon crosslinking among Sn4–oxo clusters. This study deepens our understanding of Sn–oxo cluster photolithographic reaction mechanisms, offering critical insights for optimizing developers and enhancing resolution and sensitivity. These findings are expected to aid the realization of sub‐10 nm node technology.