Directed Self-Assembly of Block Copolymer Thin Films into Useful Organized Patterns for Microelectronics and Nanofabrication.

这项拨款支持的研究，创造了关于制造工艺的新理解和能力，使制造极小的表面上的图案和特征-只有几十亿分之一米（几纳米）的范围。这些长度的精密制造正在推动国家重要领域的制造进步，包括微电子，光学材料，传感器，化学净化膜和量子材料。该奖项支持嵌段共聚物纳米制造的基础研究。当两种不“喜欢”彼此的不同的传统聚合物混合时，这两种聚合物就会像油和水一样分离。然而，当这两种聚合物相互结合形成嵌段共聚物时，宏观分离被抑制，而发生纳米级的分离。小于一百（100）、十（10）、甚至五(5)纳米的特征是自动生成的，否则不容易创建。这个项目的重点是在空间上指导表面上的纳米级分离，以便形成合理组织和有用的（而不是随机的）模式。一个例子是在计算机芯片的半导体表面进行纳米图形化，使它们运行得更快、更节能，并且可以更复杂。该研究整合了材料科学与工程、化学和纳米制造的先进概念。跨学科研究有助于扩大不同群体对基础研究的参与，并对科学和工程教育产生建设性影响。本研究特别解决了通过利用边界定向外延将垂直取向嵌段共聚物片层域的自组装登记和指导成合理控制的亚光刻模式的挑战。边界定向外延利用具有不同表面组成的衬底区域之间空间边界固有的突然化学对比来指导嵌段共聚物的配准、排列和自组装。它的优势是显著的：边界可以在平面和相对较大的特征之间定义，从而避免了对沟槽或高分辨率化学模式的需求。驱动自组装的机制还未被充分探索。该项目确定了边界定向外延的化学成分/优先窗口；量化边界粗糙度对装配的影响；描述缺陷是如何产生的；并了解大会如何随着时间的推移而演变。该项目研究并展示了纳米制造、材料合成和纳米光刻的边界定向外延；研究具有弯曲边界和复杂形状的模板上的组装-对于许多应用程序至关重要；并且，拓宽了模板材料库，可以利用这些模板材料来推进这种现象的普遍性。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This grant supports research that creates new understanding and capabilities regarding a manufacturing process enabling the fabrication of patterns and features on surfaces that are extremely small -- only a few billionths of a meter (a few nanometers) in extent. Precision fabrication at these lengths is driving manufacturing advances in areas of national importance including microelectronics, optical materials, sensors, chemical purification membranes, and quantum materials. This award supports fundamental research on block copolymer-based nanofabrication. When two different conventional polymers that do not “like” each other are mixed, the two polymers separate – like oil and water. However, when these two polymers are bonded to each other – to form a block copolymer – macroscopic separation is inhibited, and nanoscale segregation occurs instead. Features smaller than hundred (100), ten (10), and even five (5) nanometers are generated automatically, that cannot be easily created otherwise. This project focuses on spatially directing this nanoscale segregation on surfaces so that rationally organized and useful (as opposed to random) patterns can be formed. An example is nanopatterning the surfaces of semiconductors for computer chips so that they perform faster, are more energy efficient, and can be more complex. The research integrates advanced concepts from materials science and engineering, chemistry, and nanomanufacturing. The interdisciplinary research helps widen the involvement of diverse groups in fundamental research and constructively influences science and engineering education.This research specifically addresses the challenge of registering and directing the self-assembly of vertically oriented block copolymer lamellar domains into rationally controlled sub-lithographic patterns through the exploitation of boundary-directed epitaxy. Boundary-directed epitaxy uses the abrupt chemical contrast that is inherent at spatial boundaries between regions on a substrate with different surface composition to direct the registration, alignment, and self-assembly of block copolymers. The advantages are substantial: the boundaries can be defined between features that are planar and relatively large – circumventing the need for trenches or high-resolution chemical patterns. The mechanisms that drive self-assembly are highly unexplored. The project determines the chemical composition / preferentiality window for boundary-directed epitaxy; quantifies the impact of boundary-roughness on assembly; characterizes how defects arise; and understands how the assembly evolves over time. The project studies and demonstrates boundary-directed epitaxy for nanofabrication, materials synthesis, and nanolithography; investigates assembly on templates with curved boundaries and complex shapes – essential for many applications; and, broadens the library of template materials that can be exploited to advance the generality of the phenomenon.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.