Leniart Arkadiusz A, Pula Przemyslaw, Sitkiewicz Andrzej, Majewski Pawel W
Department of Chemistry, University of Warsaw, Warsaw, 02089, Poland.
ACS Nano. 2020 Apr 28;14(4):4805-4815. doi: 10.1021/acsnano.0c00696. Epub 2020 Mar 17.
Laser annealing is a competitive alternative to conventional oven annealing of block copolymer (BCP) thin films enabling rapid acceleration and precise spatial control of the self-assembly process. Localized heating by a moving laser beam (zone annealing), taking advantage of steep temperature gradients, can additionally yield aligned morphologies. In its original implementation it was limited to specialized germanium-coated glass substrates, which absorb visible light and exhibit low-enough thermal conductivity to facilitate heating at relatively low irradiation power density. Here, we demonstrate a recent advance in laser zone annealing, which utilizes a powerful fiber-coupled near-IR laser source allowing rapid BCP annealing over a large area on conventional silicon wafers. The annealing coupled with photothermal shearing yields macroscopically aligned BCP films, which are used as templates for patterning metallic nanowires. We also report a facile method of transferring laser-annealed BCP films onto arbitrary surfaces. The transfer process allows patterning substrates with a highly corrugated surface and single-step rapid fabrication of multilayered nanomaterials with complex morphologies.
激光退火是一种用于嵌段共聚物（BCP）薄膜的传统烘箱退火的竞争性替代方法，能够实现自组装过程的快速加速和精确空间控制。利用陡峭的温度梯度，通过移动激光束进行局部加热（区域退火），还可以产生取向形态。在其最初的应用中，它仅限于特殊的涂锗玻璃基板，这种基板吸收可见光并具有足够低的热导率，以便在相对较低的辐照功率密度下促进加热。在这里，我们展示了激光区域退火的最新进展，它利用强大的光纤耦合近红外激光源，能够在传统硅晶片上大面积快速进行BCP退火。退火与光热剪切相结合，可产生宏观取向的BCP薄膜，这些薄膜用作图案化金属纳米线的模板。我们还报告了一种将激光退火的BCP薄膜转移到任意表面的简便方法。转移过程允许对具有高度波纹表面的基板进行图案化，并单步快速制造具有复杂形态的多层纳米材料。
