Coordinating Photoacid Generators Enable Site-Defined Metal–Oxo Cluster Lithography

Lithographic patterning, which employs the solubility switch of photoresists to convert optical signals into nanostructures on the substrate, constitutes the primary top-down approach for high-precision nanomanufacturing. However, the stochastic defects arising from inhomogeneous reaction sites in photoresists pose a formidable challenge to reconciling the precision of sub-10 nm lithography. In this study, we present a coordinating photoacid generator (cPAG)-driven lithography strategy that has achieved a performance breakthrough through precise spatial control of acid sites. The resulting zirconium-oxo cluster photoresists, operating via cPAG-triggered precoordination and cluster cross-linking, demonstrate a two-orders-of-magnitude decrease in UV exposure dose. Furthermore, electron beam lithography has been demonstrated to achieve a sub-10 nm line width, underscoring its suitability for high-resolution and high-sensitivity applications. This strategy is versatile across cPAGs with diverse structures and is also applicable to other metal oxide photoresist systems, including titanium-oxo and zinc-oxo clusters. This work introduces a cPAG design tailored for cluster-based photoresists and validates their ability to overcome the intrinsic trade-off in resolution, line edge roughness, and sensitivity, providing a framework for developing next-generation photoresists.