Block copolymer micelle nanolithography
Block copolymer micelle nanolithography
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DOI：
10.1088/0957-4484/14/10/314
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发表时间：
2003-10-01
期刊：
影响因子：
3.5
通讯作者：
Spatz, JP
中科院分区：
文献类型：
--
作者：
Glass, R;Möller, M;Spatz, JP
直径在2 - 8纳米之间的金纳米团簇以不同的图案几何形状沉积在固体衬底上。这种方法的基础是聚苯乙烯-b-聚[2-乙烯基吡啶（HAuCl4）]二嵌段共聚物胶束在固体载体（如硅片或玻璃盖卡）上自组装成均匀的单束薄膜。作为金属前驱体的HAuCl4或由于前驱体还原而形成的单个固体金纳米颗粒嵌套在二嵌段共聚物胶束中心。随后对干膜进行氢、氧或氩气等离子体处理，通过完全去除聚合物，导致金纳米粒子沉积在衬底上。金点图案类似于等离子体处理前的胶束图案。点之间的分离距离由二嵌段共聚物的分子量控制。通过将双嵌段共聚物胶束的自组装与光刻或电子束光刻形成的预结构相结合，克服了单个点之间的分离距离或图案几何形状的限制。由于溶剂在预先结构的衬底上蒸发而产生的收缩液膜的毛细力将胶束推到这些确定的地形的角落。采用单束薄膜作为负电子束阻胶剂，证明了一种更直接的工艺。被电子照射的胶束被化学修饰，几乎不能从衬底上溶解，而未暴露的胶束可以被合适的溶剂剥离。如果在电子束处理之前，在单束薄膜上再涂上一层5nm厚的导电碳层，该工艺也适用于电子隔离基板，如玻璃盖板卡瓦。圆柱形嵌段共聚物胶束的应用也允许形成4纳米宽的线，可以是1-50微米长，也可以组织在定义的非周期结构中。
Au-nanoclusters between 2 and 8 nm in diameter were deposited onto solid substrates in different pattern geometries. The basis of this approach is the self-assembly of polystyrene-b-poly[2-vinylpyridine (HAuCl4)] diblock copolymer micelles into uniform monomicellar films on solid supports such as Si-wafers or glass cover slips. HAuCl4 as metallic precursor or a single solid Au-nanoparticle caused by reduction of the precursor are embedded in the centre of diblock copolymer micelles. Subsequent hydrogen, oxygen or argon gas plasma treatment of the dry film causes deposition of Au-nanoparticles onto the substrate by entire removal of the polymer. The Au-dot patterns resemble the micellar patterns before the plasma treatment. Separation distances between the dots is controlled by the molecular weight of the diblock copolymers. The limitation of the separation distance between individual dots or the pattern geometry is overcome by combining self-assembly of diblock copolymer micelles with pre-structures formed by photo or e-beam lithography. Capillary forces of a retracting liquid film due to solvent evaporation on the pre-structured substrate push micelles in the corners of these defined topographies. A more direct process is demonstrated by applying monomicellar films as negative e-beam resist. Micelles that are irradiated by electrons are chemically modified and can hardly be dissolved from the substrate while non-exposed micelles can be lifted-off by suitable solvents. This process is also feasible on electrical isolating substrates such as glass cover slips if the monomicellar film is coated in addition with a 5 nm thick conductive layer of carbon before e-beam treatment. The application of cylindrical block copolymer micelles also allows for the formation of 4 nm wide lines which can be 1-50 mum long and also be organized in defined aperiodic structures.