Synergistic Tripartite Molecular Design of Halogen‐Engineered Organotin Clusters Enabling 10 mJ cm ⁻² EUV Lithography

Organotin clusters are promising candidates for extreme ultraviolet (EUV) lithography but often suffer from insufficient sensitivity. To address this challenge, we report the first systematic library of halogen‐engineered isostructural dinuclear organotin clusters (Sn2‐4X, X = F, Cl, Br, I), designed to enhance EUV absorption via halogen incorporation. Our strategy features a synergistic tripartite molecular design integrating: (1) radiation‐labile Sn─C bonds for efficient ionization and cleavage; (2) halogenated aromatic ligands to boost absorption cross‐sections and etch resistance; and (3) triethanolamine (TEA) ligands to facilitate intermolecular cross‐linking via hydrogen atom transfer (HAT). This rational engineering significantly amplifies lithographic performance. Notably, Sn2‐4F achieves a record sensitivity of 10 mJ cm −2 alongside ultrahigh resolution (10 nm), establishing a new benchmark for metal–organic clusters (MOCs). Mechanistically, we reveal a fundamental dichotomy where inner‐shell ionization of heavy atoms governs EUV sensitivity, whereas “kinetic overkill” dominates electron beam lithography (EBL). Furthermore, a halogen‐dependent dissociative electron attachment (DEA) pathway is elucidated, which reinforces the lithographic network through Sn─X coordination. This work bridges the gap between molecular design, radiation physics, and chemistry, offering a robust roadmap for next‐generation high‐sensitivity EUV photoresists.