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Abstract A new type of a positive tone chemically amplified photoresist based on well‐defined, sequence‐controlled polypeptoids with ten repeat‐units are synthesized and their potential for extreme‐UV lithography (EUVL) is demonstrated, resulting in line‐space patterns of 70 nm pitch. The synthesized samples contain 4‐(ethyl) phenol (Eph) and propyne (Ppy) side chains, while their change in solubility upon exposure is induced by the deprotection of 4‐(ethyl) phenol side groups. The resist performance is evaluated using deep UV and extreme‐UV lithography. While all samples are developable in isopropyl alcohol, the content, and the sequence of hydrophobic alkyne side chains lead to a detectable change in solubility, dissolution rate, and resist performance. 

Abstract Poly(styrene‐co‐N‐maleimide) copolymers bearingtert‐butoxycarbonyl (t‐BOC)‐protected amine groups attached to side chains of varying lengths are synthesized via activators regenerated by electron transfer atom transfer radical polymerization (ARGET‐ATRP) and investigated from the perspective of photoresist applications. The length of the alkyl substituents enables control of thermal properties as well as hydrophobicity, which are critically important for resist processing. Removal of the acid labilet‐BOC group during deep‐UV (DUV)exposure shifts solubility in the exposed areas and well‐defined line space patterns of 1 µm are obtained for the selected copolymers. The correlation between glass transition temperature (T_g) and solubility contrast determines the lithographic performance where the copolymers with shorter alkyl chains exhibit promising results. 

Abstract Hairy nanoparticles (HNPs) constitute a class of hybrid nanocomposites that are resistant to aggregation and agglomeration, although the green, large‐scale synthesis of HNPs remains a challenge. In this work, 25 nm‐diameter silica‐core HNPs with a poly(methyl methacrylate) (PMMA) shell were synthesized using a graft‐from approach in aqueous miniemulsion, employing atom transfer radical polymerization with activators regenerated by electron transfer (ARGET‐ATRP). In particular, this work used tetrabutylammonium bromide (TBAB)‐assisted phase transfer of monomer, markedly improving upon earlier methods by showing that phase transfer could take place in the absence of organic solvents. Furthermore, syntheses with selected monomer addition rates produced HNP graft densities ranging from 0.011 to 0.017 chains/nm²and shell thicknesses ranging from 2.5 to 11 nm. Finally, analysis of reaction kinetics revealed that shell growth reached completion in as little as 2 hr, confirmed by the synthesis of >1 g of PMMA‐shell HNPs in a reduced timeframe.