Triblock Terpolymers for Self-assembled Nanolithography

自组装提供了创建具有电子或化学功能的良好控制的纳米结构的能力，并且使得能够合成各种有用的器件。二嵌段共聚物自组装成特征尺寸通常为10-50 nm的微区的周期性阵列，并且已被用作自组装的“抗蚀剂”以限定可用于制造广泛的器件（例如硅电容器和晶体管、光子晶体和图案化磁介质）的周期性图案。然而，二嵌段共聚物中的层状、圆柱形或球形微区通常形成具有六方对称性的光栅图案或紧密堆积结构。图案几何形状的这种限制限制了它们的器件应用，使得期望产生具有更宽范围的几何形状和应用的自组装图案。这一建议的智力价值是三嵌段三元共聚物的发展，形成具有各种几何形状的薄膜。工作包括设计三嵌段三元共聚物，以形成具有特定几何形状的膜，例如宽或密间隔的线，具有特定边缘调制的线，结或弯曲，或非紧密堆积排列的圆柱体或球体阵列;合成具有适当嵌段化学，相互作用和体积分数的聚合物;理解加工效应，包括衬底处理和退火过程;模拟自组装;以及在一个嵌段内产生磁性纳米颗粒以直接形成功能性纳米结构。这项工作的核心是三嵌段三元共聚物的模板使用基板化学和地形的调查，使自组装可以引导到纳米级精度。这项工作是英国布里斯托的一个小组与麻省理工学院的一个小组之间的合作，前者在三嵌段三元共聚物的合成化学方面具有经验，后者在麻省理工学院的剑桥具有嵌段共聚物光刻和模板方面的经验。

Self-assembly provides the ability to create well-controlled nanostructures with electronic or chemical functionality and enables the synthesis of a wide range of useful devices. Diblock copolymers self-assemble into periodic arrays of microdomains with feature sizes of typically 10-50 nm, and have been used as self-assembled 'resists' to define periodic patterns useful in making a wide range of devices such as silicon capacitors and transistors, photonic crystals, and patterned magnetic media. However, the lamellar, cylindrical or spherical microdomains in diblock copolymers generally form grating patterns, or close packed structures with hexagonal symmetry. This limitation in pattern geometries restricts their device applications, making it desirable to create self-assembled patterns with a wider range of geometries and applications. The intellectual merit of this proposal is the development of triblock terpolymers which form thin films with a diverse range of geometries. The work includes design of triblock terpolymers to form films with specific geometries such as widely or closely-spaced lines, lines with specific edge modulations, junctions, or bends, or arrays of cylinders or spheres in non-close-packed arrangements; synthesis of polymers with appropriate block chemistry, interactions and volume fractions; understanding processing effects including substrate treatment and annealing processes; modeling the self-assembly; and generation of magnetic nanoparticles within one block to form functional nanostructures directly. Central to this work is an investigation of templating of triblock terpolymers using substrate chemistry and topography, so that the self-assembly can be guided to nanoscale precision. The work is a collaboration between a group in Bristol, UK, with experience in the synthetic chemistry of triblock terpolymers, and a group in MIT, Cambridge MA, with experience in block copolymer lithography and templating.