Synthesis of High Etch Contrast Poly(3-hydroxystyrene)-Based Triblock Copolymers and Self-Assembly of Sub-5 nm Features
Synthesis of High Etch Contrast Poly(3-hydroxystyrene)-Based Triblock Copolymers and Self-Assembly of Sub-5 nm Features
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DOI：
10.1021/acs.macromol.1c01611
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发表时间：
2021-10
期刊：
影响因子：
5.5
通讯作者：
Jian Sun;Changyeon Lee;C. Osuji;P. Gopalan
中科院分区：
文献类型：
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作者：
Jian Sun;Changyeon Lee;C. Osuji;P. Gopalan
采用原子转移自由基聚合（ATRP）成功合成了一系列聚（3-羟基苯乙烯）-嵌段-聚（二甲基硅氧烷）-嵌段-聚（3-羟基苯乙烯）（P3HS-b-PDMS-b-P3HS）三嵌段共聚物。由于其固有的高蚀刻对比度，蚀刻通用性和三块结构，该系统是一种有希望的个位数纳米特征图案转移的候选者。端羟基PDMS聚合物被直接官能化，引发了一个受缩醛保护的3-羟基苯乙烯单体的ATRP。所得到的三嵌段的分散度在1.10到1.26之间，并且该合成提供了对分子量和体积分数的强大控制。基团之间的大化学不相容性使得在低分子量下形成有序结构，从而产生小至9.3 nm的层状周期性。因此，该三块允许访问低于5nm的特征尺寸。相图是不对称的，相对于双块体，在P3HS块体的较低体积分数处观察到片层形态。这种不对称归因于中间块相对于末端块的分散性。
We demonstrate the successful synthesis of a series of poly(3-hydroxystyrene)-block-poly(dimethylsiloxane)-block-poly(3-hydroxystyrene) (P3HS-b-PDMS-b-P3HS) triblock copolymers by atom transfer radical polymerization (ATRP). This system is a promising candidate for pattern transfer of single-digit nanometer features, due to its intrinsic high etch contrast, etch versatility, and the triblock architecture. Hydroxy-terminated PDMS polymers were directly functionalized to initiate the ATRP of an acetal-protected 3-hydroxystyrene monomer. The resulting triblocks have dispersity ranging from 1.10 to 1.26, and the synthesis provides robust control over molecular weights and volume fractions. The large chemical incompatibility between the blocks enabled the formation of ordered structures at low molecular weights, which yielded lamellar periodicities as small as 9.3 nm. This triblock hence permits access to sub-5 nm feature sizes. The phase diagram is asymmetric, with lamellar morphologies observed at lower volume fractions of the P3HS block, relative to the diblocks. This asymmetry is ascribed to the dispersity of the middle block relative to the end blocks.