Periodic arrays of metal nanorings and nanocrescents fabricated by a scalable colloidal templating approach

• Published in: Journal of colloid and interface science Vol. 409; pp. 52 - 58
• Main Authors: Liu, Xuefeng, Choi, Baeck, Gozubenli, Numan, Jiang, Peng
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier Inc 01-11-2013; Elsevier
• Subjects: Arrays; Chemistry; Chromium - chemistry; Colloidal state and disperse state; Colloids; Colloids - chemistry; crystals; Exact sciences and technology; General and physical chemistry; Gold - chemistry; Metal Nanoparticles - chemistry; metals; Nanocomposites; Nanocrescents; Nanofabrication; Nanomaterials; Nanorings; Nanostructure; Particle Size; Physical and chemical studies. Granulometry. Electrokinetic phenomena; polymers; Polymers - chemistry; Self-assembly; Semiconductors; silica; Silicon dioxide; Silicon Dioxide - chemistry; Surface Properties; Template; Trenches; Nanocrescents; Self-assembly; Nanofabrication; Nanorings; Template; Self assembly; Binary compound; Microsphere; Semiconductor materials; Device; Crystals; Polymer; Etching; Silica; Substrate; Tilt angle; Technology; Microparticle; Spin-on coating; Nanoring; Spherical particle; Structure; Wafer
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2013.07.018

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•Periodic metal nanorings and nanocrescents are templated by a scalable approach.•Non-close-packed monolayer silica colloidal crystals are used as templates.•Continuous transition from concentric to eccentric nanorings to nanocrescents.•This scalable bottom-up technology is compatible with standard microfabrication.
Here, we report a scalable bottom-up approach for fabricating periodic arrays of metal nanorings and nanocrescents. Wafer-scale monolayer silica colloidal crystals with an unusual non-close-packed structure prepared by a simple and rapid spin-coating technology are used as both etching and shadowing masks to create nanoring-shaped trenches in between templated polymer posts and sacrificial nanoholes. Directional deposition of metals in the trenches followed by liftoff of the polymer posts and the sacrificial nanoholes results in forming ordered metal nanorings. The inner and outer radii of the final nanorings are determined by the sizes of the templated polymer posts and the silica microspheres which can be easily adjusted by tuning the spin-coating and templating conditions. Most importantly, by simply controlling the tilt angle of the substrate toward the directional metal beams, continuous geometric transition from concentric nanorings to eccentric nanorings to nanocrescents can be achieved. This new colloidal templating approach is compatible with standard semiconductor microfabrication, promising for mass-production and on-chip integration of periodic nanorings and nanocrescents for a wide spectrum of technological applications ranging from nanooptical devices and ultrasensitive biosensing to magnetic memories and logic circuits.