氟硅嵌段共聚物自组装创制亚5 nm特征微域

Self-assembly of fluorosilicone block copolymers for fabricating of sub-5 nm feature-sized microdomains

摘要:

通过阴离子聚合（LAP）与端基修饰合成聚三氟丙基甲基硅氧烷链转移剂PMTFPS-CTA，结合可逆加成-断裂链转移（RAFT）分别与侧链含苯基（BzMA）、萘基（1NpMMA）和蒽基（AnMMA）的甲基丙烯酸酯单体聚合，得到无机/有机杂化嵌段共聚物PMTFPS-b-PBzMA、PMTFPS-b-P1NpMMA和PMTFPS-b-PAnMMA。1HNMR和FTIR表征确定了所制备的嵌段共聚物结构。GPC结果表明，所得的嵌段共聚物具有较窄的分子量分布（?<1.5）。DSC和TGA分析表明，嵌段共聚物的玻璃化转变温度（50、79、154 ℃）与热分解温度（275、255、253 ℃）均适配热退火工艺条件。SAXS结果表明， PMTFPS-b-PBzMA系列材料在80~110 ℃退火后即可形成层状相，最小特征尺寸为4.9 nm，且标度关系满足d∝N0.62，证实了该嵌段共聚物具有强微相分离特性。此外，PMTFPS的高硅含量赋予材料内在刻蚀对比度，为导向自组装光刻提供兼具分辨率与刻蚀性能的新材料。

Abstract:

Poly(trifluoropropylmethylsiloxane) chain transfer agent (PMTFPS-CTA) was synthesized via living anionic polymerization (LAP) followed by end-group modification. Subsequently, reversible addition-fragmentation chain transfer (RAFT) polymerization was employed to copolymerize PMTFPS-CTA with methacrylate monomers bearing phenyl (BzMA), naphthyl (1NpMMA), and anthryl (AnMMA) side chains, yielding the block copolymers PMTFPS-b-PBzMA, PMTFPS-b-P1NpMMA, and PMTFPS-b-PAnMMA.The structures of the block copolymers were confirmed by 1HNMR and FTIR. GPC indicated narrow molecular weight distributions (?<1.5). DSC and TGA analyses revealed glass transition temperatures (50, 79, 154 ℃) and thermal decomposition temperatures (275, 255, 253 ℃), compatible with thermal annealing conditions. SAXS results demonstrated that PMTFPS-b-PBzMA formed lamellar phases after annealing at 80~110 ℃, achieving a minimum feature size of 4.9 nm. The scaling relationship (d∝N0.62) confirmed strong microphase separation of the block copolymer. Additionally, the high silicon content of PMTFPS provides intrinsic etching contrast to the material, offering a novel material for directed self-assembly lithography with combined resolution and etching performance.