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Otte MA, Solis-Tinoco V, Prieto P, Borrisé X, Lechuga LM, González MU, Sepulveda B. Tailored Height Gradients in Vertical Nanowire Arrays via Mechanical and Electronic Modulation of Metal-Assisted Chemical Etching. Small 2015; 11:4201-4208. [PMID: 26033973 DOI: 10.1002/smll.201500175] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 04/26/2015] [Indexed: 06/04/2023]
Abstract
In current top-down nanofabrication methodologies the design freedom is generally constrained to the two lateral dimensions, and is only limited by the resolution of the employed nanolithographic technique. However, nanostructure height, which relies on certain mask-dependent material deposition or etching techniques, is usually uniform, and on-chip variation of this parameter is difficult and generally limited to very simple patterns. Herein, a novel nanofabrication methodology is presented, which enables the generation of high aspect-ratio nanostructure arrays with height gradients in arbitrary directions by a single and fast etching process. Based on metal-assisted chemical etching using a catalytic gold layer perforated with nanoholes, it is demonstrated how nanostructure arrays with directional height gradients can be accurately tailored by: (i) the control of the mass transport through the nanohole array, (ii) the mechanical properties of the perforated metal layer, and (iii) the conductive coupling to the surrounding gold film to accelerate the local electrochemical etching process. The proposed technique, enabling 20-fold on-chip variation of nanostructure height in a spatial range of a few micrometers, offers a new tool for the creation of novel types of nano-assemblies and metamaterials with interesting technological applications in fields such as nanophotonics, nanophononics, microfluidics or biomechanics.
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Affiliation(s)
- M A Otte
- NanoBiosensors and Bioanalytical Applications Group, Institut Catala de Nanociencia i Nanotecnologia (ICN2), Consejo Superior de Investigaciones Científicas (CSIC) & CIBER-BBN, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - V Solis-Tinoco
- NanoBiosensors and Bioanalytical Applications Group, Institut Catala de Nanociencia i Nanotecnologia (ICN2), Consejo Superior de Investigaciones Científicas (CSIC) & CIBER-BBN, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - P Prieto
- IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, 28760, Tres Cantos, Madrid, Spain
| | - X Borrisé
- Nanolithography Laboratory, Institut Catala de Nanociencia i Nanotecnologia (ICN2) & CNM-IMB (CSIC), Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - L M Lechuga
- NanoBiosensors and Bioanalytical Applications Group, Institut Catala de Nanociencia i Nanotecnologia (ICN2), Consejo Superior de Investigaciones Científicas (CSIC) & CIBER-BBN, Campus UAB, Bellaterra, 08193, Barcelona, Spain
| | - M U González
- IMM-Instituto de Microelectrónica de Madrid (CNM-CSIC), Isaac Newton 8, PTM, 28760, Tres Cantos, Madrid, Spain
| | - B Sepulveda
- Magnetic Nanostructures Group, Institut Catala de Nanociencia i Nanotecnologia (ICN2), Consejo Superior de Investigaciones Científicas (CSIC), Campus UAB, Bellaterra, 08193, Barcelona, Spain
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