Fundamentals of Block Copolymer Directed Assembly

技术概述：提出了一个实验计划，旨在发现新的定向组装方法及其在嵌段共聚物域的2D阵列中实现良好的平移和取向顺序的局限性，这些方法最终可能导致可以转移到底层衬底的纳米粒子。 定向自组装技术提出的调查，即由光学和电子束光刻定义的区域的边缘用于注册和模板的顺序。 重点将放在理解的有序和无序过程中的熔体的单层和多层膜的球形域嵌段共聚物和它们的共混物与均聚物在这些地区。 国家的最先进的扫描力显微镜和掠入射小角度X射线衍射将用于在一个互补的方式，以精确地定义在这些层的顺序。 定向自组装也是感兴趣的圆柱形域嵌段共聚物膜的圆柱体平行于膜表面。 在这里，控制位错的平衡浓度和使用附近的通道边缘的热解离的组件的向错是主要的挑战。 这些实验将补充与Glenn Fredrickson在UCSB合作的2D嵌段共聚物排序的场论数值模拟。 非技术概要：10纳米尺度上的规则特征图案化可以实现诸如高密度磁存储、超规则纳米多孔过滤膜和量子点阵列等应用。 这种图案化远远超出了直接使用光（光学光刻）的可能性，但该项目旨在探索使用光学光刻来创建更大规模特征的可能性，这些特征可以指导更小嵌段共聚物域的高度完美阵列的组装，以创建所需的图案。 主要目标是了解此类阵列中缺陷的原因以及该方法的总体限制。 本科生将在学年和夏季参与研究。 该研究小组将继续接待来自外国的访问研究生，为期一年，以提高国际意识。 主要重点将放在发展研究生的沟通和演讲技巧，特别是在国家甚至国际会议的背景下。 将与有兴趣利用这项研究成果的各种工业关注的纳米技术小组开展互动。

TECHNICAL SUMMARY:An experimental program is proposed aimed at discovering both new directed assembly methods and their limitations for achieving good translational and orientational order in 2D arrays of block copolymer domains, methods that could ultimately lead to nanopatterns that could be transferred to underlying substrates. Directed self-assembly techniques are proposed for investigation whereby the edges of regions defined by optical and electron beam lithography serve to register and template the order. Emphasis will be placed on understanding the ordering and disordering processes in melts of both single layer and multilayer films of spherical domain block copolymers and their blends with homopolymers in such regions. State-of-the art scanning force microscopy and grazing incidence small angle X-ray diffraction will be used in a complementary fashion to precisely define the order in these layers. Directed self-assembly is also of interest for cylindrical domain block copolymer films with cylinders parallel to the film surface. Here controlling the equilibrium concentration of dislocations and the thermal unbinding of their component disclinations using nearby channel edges is the primary challenge. These experiments will be supplemented with field theoretic numerical simulations of 2D block copolymer ordering in collaboration with Glenn Fredrickson at UCSB. NON-TECHNICAL SUMMARY:Patterning of regular features on the scale of 10 nanometers can enable applications such as ultrahigh density magnetic storage, ultraregular nanoporous filtration membranes and quantum dot arrays. Such patterning is well beyond what is possible directly using light (optical lithography) but this project aims to explore the possibilities of using optical lithography to create larger scale features that can direct the assembly of highly perfect arrays of much smaller block copolymer domains to create the desired patterns. Understanding the causes of imperfections in such arrays and the overall limits of the method are major goals. Undergraduates will be involved in the research both during the academic year and the summer. The research group will continue to host visiting graduate students from foreign countries for periods up to one year to promote international awareness. Major emphasis will be placed on developing graduate student communication and presentation skills, especially in the context of national and even international meetings. Interactions will be developed with nanotechnology groups at various industrial concerns interested in utilizing the results of this research.