基于羧酸肟酯光敏基团的非化学放大型聚合物光刻胶  

Nonchemically-amplified Resists Based on Photosensitive Oxime Ester Functionalized Polystyrene

作　　者：安惠雯 廉鹏 陈金平[1,2] 于天君 曾毅[1,2] 李嫕[1,2] Hui-wen An;Peng Lian;Jin-ping Chen;Tian-jun Yu;Yi Zeng;Yi Li(Key Laboratory of Photochemical Conversion and Optoelectronic Materials,Technical Institute of Physics and Chemistry,Chinese Academy of Sciences,Beijing 100190;University of Chinese Academy of Sciences,Beijing 100049)

机构地区：[1]中国科学院理化技术研究所光化学转换与功能材料重点实验室,北京100190 [2]中国科学院大学,北京100049

出　　处：《高分子学报》2024年第10期1313-1324,共12页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号22090012)资助项目.

摘　　要：合成了2种羧酸肟酯光敏基团修饰的苯乙烯类单体2,2,2-三氟-1-(4'-乙烯基-[1,1'-联苯]-4-基)乙-1-酮-O-(3-甲基苯甲酰基)肟(OXE-P)和2,2,2-三氟-1-(4'-乙烯基-[1,1'-联苯]-4-基)乙烷-1-酮-O-噻吩-2-甲酰肟(OXE-S)通过核磁共振氢谱(1H-NMR)、高分辨率质谱(HRMS)表征了单体分子结构.采用可逆加成-断裂链转移(RAFT)聚合方法制备得了2种新型聚合物POXE-P和POXE-S,使用凝胶渗透色谱(GPC)表征了聚合物分子量大小及其分布.结果表明,聚合物具有良好的溶解性、热稳定性和成膜性,满足作为光刻胶材料的要求.将聚合物分别溶于光刻胶溶剂,形成非化学放大型光刻胶.通过电子束光刻测试了POXE-P非化学放大型光刻胶的光刻性能,结果表明,POXE-P光刻胶可获得50 nm HP(half-pitch)的光刻图案.红外光谱(FTIR)和原位产物分析研究POXE-P光刻胶的曝光机理,表明肟酯结构在曝光后发生分解,形成了羰基化合物、二氧化碳等分子.聚合物侧链的结构变化以及聚合物链间可能存在的自由基交联反应使得聚合物在曝光前后发生了溶解度转变,显影后形成负性光刻图案.Two styrene derivatives 2,2,2-trifluoro-1-(4'-vinyl-[1,1'-biphenyl]-4-yl)ethan-1-one-O-(3-methylbenzoyl)oxime(OXE-P)and 2,2,2-trifluoro-1-(4'-vinyl-[1,1'-biphenyl]-4-yl)ethan-1-one-O-thiophene-2-carbonyl oxime,OXE-S)modified by photosensitive oxime ester group were synthesized.They were characterized by 1H nuclear magnetic resonance(^(1)H-NMR)spectroscopy and high-resolution mass spectrometry(HRMS).New polymers(POXE-P and POXE-S)were prepared by the reversible addition-fragmentation transfer(RAFT)polymerization,and were further characterized by gel permeation chromatography(GPC),giving molecular weights(M_(w))of 8.3 kDa and 7.2 kDa,and polydispersites(D)of 1.1.Both polymers possess good solubility,thermal stability and film-forming capability,which meet the requirements of resist materials.The polymers were dissolved separately in the propylene glycol methyl ether acetate(PGMEA)to form nonchemically-amplified resists(n-CARs).The lithographic performance of the POXE-P resist was examined by e-beam lithography,giving a 50 nm HP(halfpitch)lithographic pattern.The mechanism of POXE-P resist during exposure was investigated by Fourier transform infrared spectrometer(FTIR)and in situ outgassing analysis.It showed that the oxime ester group decomposed during exposure to form carbonyl compounds,CO_(2),and other small molecules.The cleavage of side chains and the possible crosslinking led to the solubility switch of the polymer,resulting in negative lithographic patterns.

关 键 词：非化学放大型光刻胶 可逆加成-断裂链转移(RAFT)聚合 羧酸肟酯 电子束光刻 机理 

分 类 号：TN405[电子电信—微电子学与固体电子学] TQ317[化学工程—高聚物工业]