{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T09:04:22Z","timestamp":1789376662931,"version":"build-2803163510"},"reference-count":49,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2026,9,12]],"date-time":"2026-09-12T00:00:00Z","timestamp":1789171200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007053","name":"Korea Institute of Energy Technology Evaluation and Planning","doi-asserted-by":"publisher","award":["RS-2024-00394769"],"award-info":[{"award-number":["RS-2024-00394769"]}],"id":[{"id":"10.13039\/501100007053","id-type":"DOI","asserted-by":"publisher"}]},{"award":["RS-2024-00394769"],"award-info":[{"award-number":["RS-2024-00394769"]}],"id":[{"id":"https:\/\/ror.org\/02zq38y32","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007053","name":"Ministry of Climate, Energy & Environment","doi-asserted-by":"publisher","award":["RS-2024-00394769"],"award-info":[{"award-number":["RS-2024-00394769"]}],"id":[{"id":"10.13039\/501100007053","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Controlling dimensional fidelity and line-edge roughness is important in chemically amplified negative-tone imaging. In this study, two three-arm random terpolymers containing different acid-labile protecting groups were synthesized via core-first reversible addition\u2013fragmentation chain-transfer (RAFT) polymerization to examine the influence of protecting-group structure within a common star-polymer framework. HTT 334 contained tert-butyl methacrylate (t-BMA), whereas HTM 334 contained 2-methyl-2-adamantyl methacrylate (MAMA). The two polymers exhibited comparable molecular weights and compositions, with narrow dispersities of 1.14 and 1.16. Thermal analysis showed that HTM 334 had a slightly higher glass-transition temperature than HTT 334 (77 and 73 \u00b0C, respectively). Fourier transform infrared (FT-IR) spectroscopy revealed spectral changes after exposure and post-exposure baking (PEB) that were consistent with acid-catalyzed deprotection and possible intermolecular reactions involving the hydroxyethyl methacrylate units. Negative-tone patterns were formed using an n-butyl acetate developer under the selected PEB conditions of 70 \u00b0C for HTT 334 and 90 \u00b0C for HTM 334. Across nominal mask dimensions of 10\u201380 \u03bcm, HTM 334 exhibited printed-to-mask critical-dimension ratios of 0.990\u20131.039, compared with 0.915\u20131.003 for HTT 334. HTM 334 also showed lower measured line-edge roughness values of 0.22\u20130.39 \u03bcm than HTT 334, which showed values of 0.52\u20131.27 \u03bcm. At the nominal 10 \u03bcm dimension, HTM 334 exhibited a line-edge roughness of 0.27 \u03bcm and an LER\/CD ratio of 2.60%. These results indicate that an acid-labile protecting-group structure can influence thermal behavior and micrometer-scale pattern fidelity within the investigated three-arm RAFT polymer platform.<\/jats:p>","DOI":"10.3390\/polym18182223","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T08:10:23Z","timestamp":1789373423000},"page":"2223","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Effect of Acid-Labile Protecting-Group Structure on the Micrometer-Scale Patterning Performance of Core-First RAFT-Synthesized Three-Arm Photoresists"],"prefix":"10.3390","volume":"18","author":[{"given":"Jinyoung","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Energy Engineering, Soonchunhyang University, 22 Soonchunhyang-ro, Asan 31538, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-2537-4631","authenticated-orcid":false,"given":"Yura","family":"Choi","sequence":"additional","affiliation":[{"name":"Department of Energy Engineering, Soonchunhyang University, 22 Soonchunhyang-ro, Asan 31538, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"data-curation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"}]},{"given":"Eunsu","family":"Park","sequence":"additional","affiliation":[{"name":"Department of Energy Engineering, Soonchunhyang University, 22 Soonchunhyang-ro, Asan 31538, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"}]},{"given":"Kyeongjin","family":"Jang","sequence":"additional","affiliation":[{"name":"Department of Energy Engineering, Soonchunhyang University, 22 Soonchunhyang-ro, Asan 31538, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Hyungjun","family":"Noh","sequence":"additional","affiliation":[{"name":"Department of Energy Engineering, Soonchunhyang University, 22 Soonchunhyang-ro, Asan 31538, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Namchul","family":"Cho","sequence":"additional","affiliation":[{"name":"Department of Energy Engineering, Soonchunhyang University, 22 Soonchunhyang-ro, Asan 31538, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"supervision","vocabulary":"credit"},{"role":"conceptualization","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"9235","DOI":"10.1038\/srep09235","article-title":"Beyond EUV lithography: A comparative study of efficient photoresists\u2019 performance","volume":"5","author":"Mojarad","year":"2015","journal-title":"Sci. Rep."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Ito, H. (2005). Chemical amplification resists for microlithography. Microlithography Molecular Imprinting, Springer.","DOI":"10.1007\/b97574"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"030001","DOI":"10.1143\/JJAP.49.030001","article-title":"Radiation chemistry in chemically amplified resists","volume":"49","author":"Kozawa","year":"2010","journal-title":"Jpn. J. Appl. Phys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"7404","DOI":"10.1143\/JJAP.44.7404","article-title":"ArF photoresist parameter optimization for mask error enhancement factor reduction","volume":"44","author":"Lee","year":"2005","journal-title":"Jpn. J. Appl. Phys."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"84","DOI":"10.1038\/s43586-024-00361-z","article-title":"Extreme ultraviolet lithography","volume":"4","author":"Kazazis","year":"2024","journal-title":"Nat. Rev. Methods Primers"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"5444","DOI":"10.1021\/acs.chemrev.5c01043","article-title":"Advancing EUV Patterning: Innovations in Resist Platforms, Patterning Strategies, and Computational Approaches","volume":"126","author":"Biradar","year":"2026","journal-title":"Chem. Rev."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Park, J., Lee, S.-G., Vesters, Y., Severi, J., Kim, M., De Simone, D., Oh, H.-K., and Hur, S.-M. (2019). Molecular modeling of euv photoresist revealing the effect of chain conformation on line-edge roughness formation. Polymers, 11.","DOI":"10.3390\/polym11121923"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"013015","DOI":"10.1117\/1.3280258","article-title":"Single-component molecular resists containing bound photoacid generator functionality","volume":"9","author":"Lawson","year":"2010","journal-title":"J. Micro\/Nanolithography MEMS MOEMS"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"764","DOI":"10.1063\/1.109901","article-title":"Nano edge roughness in polymer resist patterns","volume":"63","author":"Yoshimura","year":"1993","journal-title":"Appl. Phys. Lett."},{"key":"ref_10","first-page":"1647","article-title":"Experimental and model-based study of the robustness of line-edge roughness metric extraction in the presence of noise","volume":"25","author":"Naulleau","year":"2007","journal-title":"J. Vac. Sci. Technol. B Microelectron. Nanometer Struct. Process. Meas. Phenom."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Lee, S., Hwang, C., Park, D.-W., Kim, I.-S., Kim, H.-C., Woo, S.-G., Cho, H.-K., and Moon, J.-T. (2004). A simple and accurate resist parameter extraction method for sub-80-nm DRAM patterns. Proceedings of the Optical Microlithography XVII, SPIE.","DOI":"10.1117\/12.536280"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"485","DOI":"10.2494\/photopolymer.28.485","article-title":"Recent progress of Negative-tone imaging Process and Materials with EUV exposure","volume":"28","author":"Fujimori","year":"2015","journal-title":"J. Photopolym. Sci. Technol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Tarutani, S., Nihashi, W., Hirano, S., Yokokawa, N., and Takizawa, H. (2013). Negative tone imaging process and materials for EUV lighography. Proceedings of the Advances in Resist Materials and Processing Technology XXX, SPIE.","DOI":"10.1117\/12.2011384"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Hirano, I., Takahashi, M., Soeda, K., Kadowaki, M., Hirahara, K., Hosono, T., Koshiyama, J., and Yazawa, T. (2023). Development of a novel cleaner for contaminant removal in equipment used in semiconductor manufacturing which reduces time and solvent waste. Proceedings of the Advances in Patterning Materials and Processes XL, SPIE.","DOI":"10.1117\/12.2656914"},{"key":"ref_15","first-page":"2998","article-title":"Negative tone molecular resists using cationic polymerization: Comparison of epoxide and oxetane functional groups","volume":"27","author":"Lawson","year":"2009","journal-title":"J. Vac. Sci. Technol. B Microelectron. Nanometer Struct. Process. Meas. Phenom."},{"key":"ref_16","unstructured":"Fujimori, T., Santillan, J., Takahashi, T., Shiobara, E., Itani, T., and Inoue, S. (2019, January 15\u201319). International symposium on extreme ultraviolet lithography. Proceedings of the International Symposium on extreme ultraviolet lithography, Monterey, CA, USA."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"741","DOI":"10.1016\/j.mee.2008.12.042","article-title":"Mesoscale simulation of molecular resists: The effect of PAG distribution homogeneity on LER","volume":"86","author":"Lawson","year":"2009","journal-title":"Microelectron. Eng."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"20367","DOI":"10.1021\/jp2027548","article-title":"Understanding acid reaction and diffusion in chemically amplified photoresists: An approach at the molecular level","volume":"115","author":"Nickel","year":"2011","journal-title":"J. Phys. Chem. C"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"1021","DOI":"10.1002\/pol.1980.170180321","article-title":"Photoinitiated cationic polymerization by dialkyl-4-hydroxyphenylsulfonium salts","volume":"18","author":"Crivello","year":"1980","journal-title":"J. Polym. Sci. Polym. Chem. Ed."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Yu, H., Liu, S., Fu, H., Cui, Z., Zhang, L., and Tian, J. (2024). POSS and PAG Dual-Containing Chemically Amplified Photoresists by RAFT Polymerization for Enhanced Thermal Performance and Acid Diffusion Inhibition. Appl. Sci., 14.","DOI":"10.3390\/app14177722"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"2420962","DOI":"10.1002\/adfm.202420962","article-title":"Key Challenges and Opportunities for Advanced Extreme Ultraviolet Lithography Photoresist Materials","volume":"35","author":"Li","year":"2025","journal-title":"Adv. Funct. Mater."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1808","DOI":"10.1021\/acs.chemmater.5c02736","article-title":"Rational Design of Degradable Multiarm Polymers Applicable for Photoimaging Materials","volume":"38","author":"Lee","year":"2026","journal-title":"Chem. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"6790","DOI":"10.1021\/acs.iecr.7b05335","article-title":"Novel Star Polymers as Chemically Amplified Positive-Tone Photoresists for KrF Lithography Applications","volume":"57","author":"Zheng","year":"2018","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"114449","DOI":"10.1016\/j.eurpolymj.2025.114449","article-title":"Synthesis of ArF photoresist polymers via continuous-flow RAFT polymerization with an efficient strategy for their thiocarbonylthio end group removal","volume":"242","author":"Xie","year":"2025","journal-title":"Eur. Polym. J."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"9766","DOI":"10.1021\/acs.macromol.4c01856","article-title":"Orthogonal atom transfer radical polymerization and reversible addition\u2013fragmentation chain transfer polymerization for controlled polymer architectures","volume":"57","author":"Niu","year":"2024","journal-title":"Macromolecules"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1016\/j.polymer.2017.06.007","article-title":"Using block copolymer architecture to achieve sub-10 nm periods","volume":"121","author":"Sun","year":"2017","journal-title":"Polymer"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"722","DOI":"10.1007\/s13233-011-0705-3","article-title":"Synthesis of ArF photoresist polymer composed of three methacrylate monomers via reversible addition-fragmentation chain transfer (RAFT) polymerization","volume":"19","author":"Sohn","year":"2011","journal-title":"Macromol. Res."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"3035","DOI":"10.1039\/D1CS00069A","article-title":"Photocontrolled RAFT polymerization: Past, present, and future","volume":"52","author":"Lee","year":"2023","journal-title":"Chem. Soc. Rev."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2100514","DOI":"10.1002\/marc.202100514","article-title":"Photo-Iniferter RAFT Polymerization","volume":"43","author":"Hartlieb","year":"2022","journal-title":"Macromol. Rapid Commun."},{"key":"ref_30","first-page":"3357","article-title":"High performance acrylic polymers for chemically amplified photoresist applications","volume":"9","author":"Allen","year":"1991","journal-title":"J. Vac. Sci. Technol. B Microelectron. Nanometer Struct. Process. Meas. Phenom."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"E307","DOI":"10.1002\/app.36973","article-title":"Synthesis of poly (vinyl ether) optical plastics by cationic copolymerization of tricyclodecane vinyl ether with functionalized vinyl ethers","volume":"126","author":"Namikoshi","year":"2012","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"2899","DOI":"10.1002\/pola.27322","article-title":"Synthesis and thermal, optical, and mechanical properties of sequence-controlled poly (1-adamantyl acrylate)-block-poly (n-butyl acrylate) containing polar side group","volume":"52","author":"Nakano","year":"2014","journal-title":"J. Polym. Sci. Part A Polym. Chem."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"4017","DOI":"10.1021\/ma00014a008","article-title":"Synthesis and characterization of poly (1-adamantyl methacrylate): Effects of the adamantyl group on radical polymerization kinetics and thermal properties of the polymer","volume":"24","author":"Matsumoto","year":"1991","journal-title":"Macromolecules"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1166\/mex.2016.1298","article-title":"Synthesis of adamantane-containing methacrylate polymers: Characterization of thermal, mechanical, dielectric and optical properties","volume":"6","author":"Tsai","year":"2016","journal-title":"Mater. Express"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Lee, C.-J., Kim, J., Lee, G.-H., Hyeon, J., Choi, Y., and Cho, N. (2024). Swelling Behavior of Acrylate-Based Photoresist Polymers Containing Cycloaliphatic Groups of Various Sizes. Materials, 17.","DOI":"10.3390\/ma17225465"},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Kim, J., Lee, C.-J., Lee, D.-G., Lee, G.-H., Hyeon, J., Choi, Y., and Cho, N. (2025). Controlling the Dissolution Behavior of (Meth) acrylate-Based Photoresist Polymers in Tetramethylammonium Hydroxide by Introducing Adamantyl Groups. Materials, 18.","DOI":"10.3390\/ma18020381"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"399","DOI":"10.2494\/photopolymer.18.399","article-title":"Tailored glass transition of ArF resists for resolution enhancement at sub-50 nm node","volume":"18","author":"Takemoto","year":"2005","journal-title":"J. Photopolym. Sci. Technol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/S0167-9317(03)00363-0","article-title":"A new nanocomposite resist for low and high voltage electron beam lithography","volume":"70","author":"Ali","year":"2003","journal-title":"Microelectron. Eng."},{"key":"ref_39","first-page":"21","article-title":"Controlled synthesis of block copolymers containing N-isopropylacrylamide by reversible addition-fragmentation chain-transfer (RAFT) polymerization","volume":"55","year":"2011","journal-title":"J. Mex. Chem. Soc."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"102","DOI":"10.1007\/s10965-016-0996-3","article-title":"Synthesis of chemically amplified photoresist polymer containing four (Meth) acrylate monomers via RAFT polymerization and its application for KrF lithography","volume":"23","author":"Li","year":"2016","journal-title":"J. Polym. Res."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1824","DOI":"10.1002\/app.20151","article-title":"Homopolymerization and copolymerization of tert-butyl methacrylate and norbornene with nickel-based methylaluminoxane catalysts","volume":"92","author":"Huang","year":"2004","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"7388","DOI":"10.1021\/acsapm.6c00500","article-title":"Synthesis of Polyhydroxyimides for Negative-Tone Photosensitive Polyimides with Enhanced Patterning Stability","volume":"8","author":"Lee","year":"2026","journal-title":"ACS Appl. Polym. Mater."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1858","DOI":"10.1002\/pola.10252","article-title":"Negative-working photoresist of methacrylate polymers based on the transesterification of the 2-hydroxyethyl group in the presence of an acid","volume":"40","author":"Lee","year":"2002","journal-title":"J. Polym. Sci. Part A Polym. Chem."},{"key":"ref_44","first-page":"773","article-title":"Design and Chemistry of Advanced Deep-UV Photoresists","volume":"12","author":"Noppakunddilograt","year":"1999","journal-title":"J. Photopolym. Sci. Technol."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"719","DOI":"10.2494\/photopolymer.13.719","article-title":"Visible Light-Sensitive Positive-Working Photopolymer Based on Poly(p-hydroxystyrene) and Vinyl Ether Crosslinker","volume":"13","author":"Noppakunddilograt","year":"2000","journal-title":"J. Photopolym. Sci. Technol."},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Umeda, T., Yamanaka, T., Iguchi, N., and Tsuzuki, S. (2015). Microbridge reduction in negative-tone imaging at photoresist point-of-use filtration. Proceedings of the Advances in Patterning Materials and Processes XXXII, SPIE.","DOI":"10.1117\/12.2085710"},{"key":"ref_47","doi-asserted-by":"crossref","unstructured":"Tsubaki, H. (2025). Negative-tone imaging (NTI) process and material technology for ArF immersion and EUV lithography. Proceedings of the Ninth International Workshop on Advanced Patterning Solutions (IWAPS 2025), SPIE.","DOI":"10.1117\/12.3092030"},{"key":"ref_48","first-page":"2265","article-title":"Improvement in linewidth roughness by postprocessing","volume":"26","author":"Chandhok","year":"2008","journal-title":"J. Vac. Sci. Technol. B Microelectron. Nanometer Struct. Process. Meas. Phenom."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Plat, M.V., Spence, C.A., Lyons, C.F., and Wilkison, A. (2001). Resolution capability and the mask error enhancement function (MEEF) for ArF and KrF lithography. Proceedings of the Optical Microlithography XIV, SPIE.","DOI":"10.1117\/12.435785"}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/18\/18\/2223\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T08:15:51Z","timestamp":1789373751000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/18\/18\/2223"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,12]]},"references-count":49,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2026,9]]}},"alternative-id":["polym18182223"],"URL":"https:\/\/doi.org\/10.3390\/polym18182223","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,12]]}}}