Recent advances in polymeric chemically amplified positive resists: Materials and design strategies

Chemically amplified resists (CARs) are essential for advanced photolithography but face critical challenges at extreme ultraviolet (EUV) nodes, including the resolution-line-edge roughness-sensitivity (RLS) trade-off and low photon utilization. To provide theoretical guidance for the design of next-generation CARs, this review systematically discusses the molecular design of positive CARs, focusing on photoacid generators (PAGs), polymer architectures, functional monomers, and additives. We discuss PAG evolution from classical onium salts to polymer-bound and naphthalimide-based systems with tunable structure-property relationships, alongside polymer backbone strategies including styrenic, acrylate, norbornene, and self-immolative platforms. The roles of functional monomers and additives are also discussed. Emerging strategies to sensitize resists-self-amplification, controlled polymerization, copolymerization of sensitive monomers and photosensitized CARs-are comprehensively reviewed. Finally, current challenges, along with design strategies for each component of the photoresist, are summarized. This review provides a unified framework connecting molecular design to lithographic performance, serving as a resource for researchers and a roadmap for next-generation CAR development.