Controlled dewetting processes on microstructured surfaces – a new procedure for thin film microstructuring
Controlled dewetting processes on microstructured surfaces – a new procedure for thin film microstructuring
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DOI：
10.1002/(sici)1439-2054(20000301)276:1
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发表时间：
2000-03
影响因子：
3.9
通讯作者：
E. Meyer;H. Braun
中科院分区：
文献类型：
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作者：
E. Meyer;H. Braun
聚合物材料的许多高科技应用都是基于其薄膜特性。这些应用与微电子器件、光学层（包括照相材料）或基于生物芯片技术的诊断系统有关。特别是在生物分析应用中，通常需要聚合物通过化学修饰将生物功能分子结合到膜中，通过旋涂或浸涂制备的薄膜和可渗透膜的完美性强烈依赖于聚合物溶液在基底上的润湿和去润湿行为。特别是制备的薄膜（厚度a30 nm）是非常敏感的去湿行为。一个典型的情况下，出现了在均质表面上的浸涂过程中，得到的膜形态图中所示。1.这些典型的功能也可以观察到duringdewetting薄熔融聚合物film.Full论文：我们描述了一个新的实验尝试togenerate定义的微结构聚合物film.Microcontact印刷的11-十一烷酸已被用来修改裸露的金sur-faces的润湿性能，以制备不良的微结构表面域downwardto 4 lm的大小。用浸涂法从聚苯乙烯的氯仿溶液中获得了厚度小于20 nm的聚苯乙烯薄膜。孔的成核和去湿过程完全由表面的非均匀性控制。通过浸涂过程中的受控去湿，获得了具有明确孔图案的大面积区域。剩余的胶片在裸金表面上没有显示出去湿的迹象。特别是在较高的聚合物浓度Rayleigh不稳定性内coalescent rims相邻holesare示出影响膜形态。讨论了通过控制去湿设计表面膜图形的一些准则，所用的低压扫描电子显微镜（LVSEM）似乎是表征厚度小于5 nm的有机膜和有机层的一种很好的方法。
Numerous high tech applications of polymer materialsbase on their thin film properties. These applications arerelated to microelectronic devices, optics layers includingphotographic material or diagnostic systems based onbiochip technology. Especially bioanalytical applicationsvery often require polymers in order to bind biofunctionalmolecules by chemical modification within the films.The perfectness of thin and ultrathin films prepared byspin-or dip-coating is strongly dependent on the wettingand dewetting behaviour of the polymer solutions on thesubstrate. In particular the preparation of ultrathin films(thickness a30 nm) is very sensitive regarding the dewet-ting behaviour. A typical scenario that appears by dewet-ting on homogeneous surfaces during the dip-coating pro-cess and the resulting film morphologies is illustrated inFig. 1.These typical features can be also observed duringdewetting of thin molten polymer films.Full Paper: We describe a new experimental attempt togenerate defined ultrathin microstructured polymer films.Microcontact printing of 11-undecanoic acid has beenused to modify the wetting properties of bare gold sur-faces to prepare poor wettable surface domains downwardto 4 lm size. Film formation of polystyrene films thinnerthan 20 nm was achieved by dip-coatingfrom a solutionof polystyrene in chloroform. The nucleation of holes andthe dewetting process was completely controlled by theheterogenity of the surface. Large areas with well definedhole patterns were achieved by the controlled dewettingduring the dip-coating process. The remaining filmshowed no indications for dewetting on the bare gold sur-face. Especially at higher polymer concentrations Ray-leigh instabilities within coalescent rims of adjacent holesare shown to influence the film morphology. Some criteriawhich are relevant for the design of surface film patternsby controlled dewetting are discussed.Low voltage scanning electron microscopy (LVSEM)which is used appears to be an excellent method for thecharacterisation of ultrathin films and organic layersdownward to 5 nm thickness.