Nitroxide mediated polymerization for narrow molecular weight distribution copolymers: application to photoresist materials

为了在微电子学中刻印亚微米特征，光刻技术是用对辐照敏感的聚合物（例如光刻）蚀刻所需的图案。光阻)。曝光后，由于溶解度的变化，光刻胶通过化学处理形成图案。线宽分辨率（LWR）等决定特征尺寸的因素取决于所使用的聚合物的类型和聚合物的性质。通常，传统的自由基聚合的两个或更多的单体是用来制造所需的共聚物的光刻胶。然而，这种聚合方法不能很好地控制链结构，而链结构是低水堆的关键。可控自由基聚合（CRP）本质上是利用自由基化学，但可以非常严格地控制分子量分布和微观结构。一些CRP方法(如：RAFT， ATRP)已应用于光刻胶材料，但其主要缺点是缺乏透明度，并且需要催化剂和链转移剂去除。我们的目标是应用另一种称为NMP的CRP变体，它不会使聚合物变色，但仍然提供受控的微观结构。然而，NMP尚未应用于光刻胶。我们的项目将首先评估NMP化学作为光刻胶聚合物的途径，可能用于193纳米光刻胶，St-Jean光化学公司（SJPC）作为工业赞助商。SJPC将为微电子工业的利基材料提供聚合化学和放大设施方面的专业知识。

To imprint sub-micron features for microelectronics, photolithography is used to etch the desired pattern with polymers that are sensitive to the irradiation (eg. photoresists). After exposure, patterns are developed by chemical treatment from the photoresists due to solubility changes. Factors such as line width resolution (LWR) that determine feature size depend on the type of polymer used and the properties of the polymer. Typically, conventional free radical polymerization of two or more monomers is used to make the desired copolymer for the photoresist. However, such a polymerization method does not control chain structure well, which is critical for LWR. Controlled radical polymerization (CRP) uses essentially free radical chemistry but can control molecular weight distribution and microstructure very tightly. Some CRP methods (eg. RAFT, ATRP) have been applied for photoresist materials but the major disadvantage is their lack of transparency and they require catalyst and chain transfer agent removal. We aim to apply another variant of CRP termed NMP, which does not leave polymers discoloured but still provides controlled microstructure. NMP has however not been applied towards photoresists. Our project will first evaluate NMP chemistry as a route towards photoresist polymer potentially for 193 nm photoresists with St-Jean Photochemicals Inc. (SJPC) as the industrial sponsor. SJPC will provide their expertise in polymerization chemistry and scale-up facilities for niche materials in the microelectronics industry.