Triblock Terpolymers for Self-assembled Nanolithography

自组装提供了创造良好控制的具有电子或化学功能的纳米结构的能力，并使广泛的有用设备的合成成为可能。两嵌段共聚物自组装成特征尺寸通常为10-50 nm的周期性微区阵列，并已被用作自组装“抗蚀剂”，以定义在制造各种器件(如硅电容器和晶体管、光子晶体和图案化磁性介质)中有用的周期性图案。然而，两嵌段共聚物中的层状、圆柱状或球状微区通常形成格栅图案，或具有六方对称性的紧密堆积结构。图案几何形状的这种限制限制了它们的设备应用，使得创建具有更广泛的几何形状和应用范围的自组装图案变得合乎需要。这一提议的智力价值在于开发了三嵌段三元聚合物，这种聚合物可以形成具有不同几何形状的薄膜。这项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薄膜，如宽或近距离的直线、具有特定边缘调制、结或弯曲的直线、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；了解包括衬底处理和热处理工艺在内的加工效应；对自组装进行建模；以及在一个嵌段内生成磁性纳米颗粒，以直接形成功能性纳米结构。这项工作的中心是利用衬底化学和拓扑学研究三嵌段三元聚合物的模板，以便自组装可以被引导到纳米级的精度。这项工作是由英国布里斯托尔的一个在三嵌段三元聚合物的合成化学方面有经验的团队和马萨诸塞州剑桥麻省理工学院的一个在嵌段共聚物光刻和模板方面有经验的团队合作完成的。

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.