Aizawa Masato, Buriak Jillian M
National Institute for Nanotechnology and the Department of Chemistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G2.
J Am Chem Soc. 2006 May 3;128(17):5877-86. doi: 10.1021/ja060366x.
Patterning technologically important semiconductor interfaces with nanoscale metal films is important for applications such as metallic interconnects and sensing applications. Self-assembling block copolymer templates are utilized to pattern an aqueous metal reduction reaction, galvanic displacement, on silicon surfaces. Utilization of a triblock copolymer monolayer film, polystyrene-block-poly(2-vinylpyridine)-block-poly(ethylene oxide) (PS-b-P2VP-b-PEO), with two blocks capable of selective transport of different metal complexes to the surface (PEO and P2VP), allows for chemical discrimination and nanoscale patterning. Different regions of the self-assembled structure discriminate between metal complexes at the silicon surface, at which time they undergo the spontaneous reaction at the interface. Gold deposition from gold(III) compounds such as HAuCl4(aq) in the presence of hydrofluoric acid mirrors the parent block copolymer core structure, whereas silver deposition from Ag(I) salts such as AgNO3(aq) does the opposite, localizing exclusively under the corona. By carrying out gold deposition first and silver second, sub-100-nm gold features surrounded by silver films can be produced. The chemical selectivity was extended to other metals, including copper, palladium, and platinum. The interfaces were characterized by a variety of methods, including scanning electron microscopy, scanning Auger microscopy, X-ray photoelectron spectroscopy, and atomic force microscopy.
利用纳米级金属薄膜对技术上重要的半导体界面进行图案化，对于金属互连和传感应用等领域至关重要。自组装嵌段共聚物模板被用于在硅表面对水相金属还原反应——电置换反应进行图案化。使用一种三嵌段共聚物单层膜，即聚苯乙烯-嵌段-聚（2-乙烯基吡啶）-嵌段-聚环氧乙烷（PS-b-P2VP-b-PEO），其两个嵌段能够将不同的金属配合物选择性传输到表面（PEO和P2VP），从而实现化学区分和纳米级图案化。自组装结构的不同区域在硅表面区分金属配合物，此时它们在界面处发生自发反应。在氢氟酸存在的情况下，由金（III）化合物如HAuCl4（水溶液）进行金沉积，反映出母体嵌段共聚物的核结构，而由Ag（I）盐如AgNO3（水溶液）进行银沉积则相反，银仅沉积在冠层之下。通过先进行金沉积，然后进行银沉积，可以制备出被银膜包围的亚100纳米金特征结构。化学选择性扩展到了其他金属，包括铜、钯和铂。通过多种方法对界面进行了表征，包括扫描电子显微镜、扫描俄歇显微镜、X射线光电子能谱和原子力显微镜。
