Nanomanufacturing and System Integration of Multi-Functional Metallic Pyramidal Probes

光学显微镜和光谱学的分辨率限制在大约光波长的一半，通常约为200至250纳米。科学家们可以利用一个锋利的金属尖端作为天线，将光聚焦到光学近场，从而收集到其他方法无法获得的纳米级光-物质相互作用的关键信息。目前最先进的近场应用尖端是一次制造一个，易碎，表面粗糙。这些制造上的不一致限制了分辨率，并经常产生不可复制的结果。该项目的目标是制造、集成、表征和推广新一代金属探针。可重复、高性能和多功能探针的传播将使高分辨率近场光学显微镜和光谱学的普及，并使其能够在用户设施中使用，从而将这项技术从少数专家的领域推广到普遍使用。研究小组将使用一种被称为模板剥离的高通量制造技术，用于可重复的、晶圆级的纳米尖贵金属锥体尖端生产。晶体取向相关的硅湿蚀刻将用于定义一个原子光滑的模板，金或银将沉积在其中。然后用环氧树脂将金属剥离，露出超光滑的亚纳米粗糙度的背面。由此产生的超光滑金属金字塔减轻了寄生随机热点，这是其他金属化技术所特有的，并促进了光能向尖端的传递和集中。将开发稳健的包装方法，将这些探针与扫描探针显微镜系统集成。这些扫描探针固定的金属金字塔将在原子力显微镜下进行质量控制，增强来自标准样品的光谱信号，同时获得地形图像。详细的制造和包装协议将在同行评审的期刊上发表，并应要求提供给研究人员。这将使近场显微镜和光谱学从少数专家使用的困难的小众技术转变为广泛的常规表征方法，被许多研究人员采用，广泛应用于纳米技术、材料科学、化学和生物学等学科。

Optical microscopy and spectroscopy is limited in resolution to roughly half the wavelength of light, generally about 200 to 250 nanometers. Scientists can overcome this limit using a sharp metal tip as an antenna to focus light into the optical near-field, gleaning crucial information about nanoscale light-matter interactions inaccessible by other methods. Current state-of-the-art tips for near field applications are fabricated one at a time, are fragile, and have rough surfaces. These manufacturing inconsistencies limit resolution and often give irreproducible results. The objective of this project is to manufacture, integrate, characterize, and disseminate a new generation of metal probes. Dissemination of reproducible, high-performance, and multi-functional probes will democratize access to high-resolution near-field optical microscopy and spectroscopy and enable its use in user facilities, promoting this technology from the realm of a few experts to general use. The research team will use a high-throughput manufacturing technique known as template stripping for reproducible, wafer-scale production of nanometrically sharp, noble metal pyramidal tips. Crystalline-orientation-dependent wet etching of silicon will be used to define an atomically smooth template, into which gold or silver will be deposited. The metal will then be stripped off, using epoxy, exposing the ultra-smooth, sub-nanometer roughness, backside surface. The resulting ultrasmooth metal pyramids mitigate parasitic random hotspots, endemic to other metallization techniques, and promote optical energy delivery to and concentration at the tip. Robust packaging methods will be developed to integrate these probes with scanning probe microscopy systems. These scanning-probe-affixed metal pyramids will be quality controlled in an atomic force microscope, enhancing spectroscopic signals from standard samples while simultaneously acquiring topographic images. Detailed manufacturing and packaging protocols will be published in peer-reviewed journals and provided to researchers upon request. This will transform near-field microscopy and spectroscopy from a difficult niche technique used by a small number of specialists to a widespread, routine characterization method adopted by many researchers in broad range of disciplines such as nanotechnology, materials science, chemistry, and biology.