Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe, Germany ; Institute of Applied Physics and Center for Functional Nanostructures (CFN), Karlsruhe Institute of Technology (KIT), 76128 Karlsruhe, Germany ; Joint Research Laboratory Nanomaterials Karlsruhe Institute of Technology (KIT)/Darmstadt University of Technology, 64287 Darmstadt, Germany.
Beilstein J Nanotechnol. 2012;3:620-8. doi: 10.3762/bjnano.3.71. Epub 2012 Sep 4.
A rapid and cost-effective lithographic method, polymer blend lithography (PBL), is reported to produce patterned self-assembled monolayers (SAM) on solid substrates featuring two or three different chemical functionalities. For the pattern generation we use the phase separation of two immiscible polymers in a blend solution during a spin-coating process. By controlling the spin-coating parameters and conditions, including the ambient atmosphere (humidity), the molar mass of the polystyrene (PS) and poly(methyl methacrylate) (PMMA), and the mass ratio between the two polymers in the blend solution, the formation of a purely lateral morphology (PS islands standing on the substrate while isolated in the PMMA matrix) can be reproducibly induced. Either of the formed phases (PS or PMMA) can be selectively dissolved afterwards, and the remaining phase can be used as a lift-off mask for the formation of a nanopatterned functional silane monolayer. This "monolayer copy" of the polymer phase morphology has a topographic contrast of about 1.3 nm. A demonstration of tuning of the PS island diameter is given by changing the molar mass of PS. Moreover, polymer blend lithography can provide the possibility of fabricating a surface with three different chemical components: This is demonstrated by inducing breath figures (evaporated condensed entity) at higher humidity during the spin-coating process. Here we demonstrate the formation of a lateral pattern consisting of regions covered with 1H,1H,2H,2H-perfluorodecyltrichlorosilane (FDTS) and (3-aminopropyl)triethoxysilane (APTES), and at the same time featuring regions of bare SiO(x). The patterning process could be applied even on meter-sized substrates with various functional SAM molecules, making this process suitable for the rapid preparation of quasi two-dimensional nanopatterned functional substrates, e.g., for the template-controlled growth of ZnO nanostructures [1].
一种快速且经济高效的光刻方法，聚合物混合光刻（PBL），被报道可在固体基底上产生具有两种或三种不同化学功能的图案自组装单层（SAM）。对于图案生成，我们在旋涂过程中使用两种不混溶聚合物在共混溶液中的相分离。通过控制旋涂参数和条件，包括环境气氛（湿度）、聚苯乙烯（PS）和聚甲基丙烯酸甲酯（PMMA）的摩尔质量以及共混溶液中两种聚合物的质量比，可以重复诱导形成纯横向形貌（PS 岛站立在基底上，同时在 PMMA 基质中隔离）。随后可以选择性地溶解形成的任一相（PS 或 PMMA），并且剩余相可以用作纳米图案化功能硅烷单层的剥离掩模。该聚合物相形态的“单层副本”具有约 1.3nm 的形貌对比度。通过改变 PS 的摩尔质量来演示 PS 岛直径的调整。此外，聚合物混合光刻法可以提供制造具有三种不同化学组分的表面的可能性：这通过在旋涂过程中在较高湿度下诱导呼吸图案（蒸发凝聚实体）来证明。在这里，我们演示了由具有 1H、1H、2H、2H-全氟癸基三氯硅烷（FDTS）和（3-氨丙基）三乙氧基硅烷（APTES）覆盖的区域以及同时具有裸露 SiO(x)区域的横向图案的形成。即使在具有各种功能 SAM 分子的米级基底上也可以应用这种图案化工艺，使得该工艺适合快速制备准二维纳米图案化功能基底，例如用于 ZnO 纳米结构的模板控制生长[1]。
