Modular Synthesis of Phthalaldehyde Derivatives Enabling Access to Photoacid Generator-Bound Self-Immolative Polymer Resists with Next-Generation Photolithographic Properties

Abstract

The resolution, line edge roughness, and sensitivity (RLS) trade-off has fundamentally limited the lithographic performance of chemically amplified resists. Production of next-generation transistors using extreme ultraviolet (EUV) lithography depends on a solution to this problem. A resist that simultaneously increases the effective reaction radius of its photogenerated acids while limiting their diffusion radius should provide an elegant solution to the RLS barrier. Here, we describe a generalized synthetic approach to phthalaldehyde derivatives using sulfur­(VI) fluoride exchange click chemistry that dramatically expands usable chemical space by enabling virtually any non-ionic photoacid generator (PAG) to be tethered to phthalaldehyde. The resulting polymers represent the first ever PAG-tethered self-immolative resists in an architecture that simultaneously displays high contrast, extraordinary sensitivity, and low roughness under EUV exposure. We believe this class of resists will ultimately enable researchers to overcome the RLS trade-off.

Emerging Trends in the Chemistry of End-to-End Depolymerization

“…155 Moreover, high-efficiency and facile methodologies to incorporate functional moieties including responsive end-caps into depolymerizable backbones without compromising depolymerization capability requires more efforts. 156 On the other hand, other depolymerizable systems that are not discussed here, including polycarbonates, 43 polyamides, 92 polyurethanes, 157 and polysaccharides, 158 also show widely attainable properties and depolymerizations. Second, the creation of depolymerizable materials with different architectures is driven by topology-dependent properties, such as stability, thermal properties, and depolymerizability.…”

“…Moreover, any undesirable degradation imparted by hydrolysis, acid, base, light irradiation, or oxidation for real applications would possibly result in alterations from the as-designed depolymerization pathways . Moreover, high-efficiency and facile methodologies to incorporate functional moieties including responsive end-caps into depolymerizable backbones without compromising depolymerization capability requires more efforts . On the other hand, other depolymerizable systems that are not discussed here, including polycarbonates, polyamides, polyurethanes, and polysaccharides, also show widely attainable properties and depolymerizations.…”

Rapid and Selective Photo‐degradation of Polymers: Design of an Alternating Copolymer with an o‐Nitrobenzyl Ether Pendant

“…There have been several examples of the use of photo‐stimulus for the degradation and/or recycling of polymers such as polystyrene, [19–22] poly(methyl methacrylate), [23] and poly(propylene oxide), [24] albeit that in most cases, chemical reactants or catalysts are necessary in addition to light irradiation. Quite recently, some attempts to degrade polymers for recycling or upcycling using just light irradiation have also been reported [25–28] …”

Rapid and Selective Photo‐degradation of Polymers: Design of an Alternating Copolymer with an o‐Nitrobenzyl Ether Pendant

“…There have been several examples of the use of photo‐stimulus for the degradation and/or recycling of polymers such as polystyrene, [19–22] poly(methyl methacrylate), [23] and poly(propylene oxide), [24] albeit that in most cases, chemical reactants or catalysts are necessary in addition to light irradiation. Quite recently, some attempts to degrade polymers for recycling or upcycling using just light irradiation have also been reported [25–28] …”