Fabrication of Nanopore Array Electrodes by Focused Ion Beam Milling

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• 作者：Yvonne H. Lanyon ; Gianluca De Marzi ; Yvonne E. Watson ; Aidan J. Quinn ; James P. Gleeson ; Gareth Redmond ; Damien W. M. Arrigan
• 刊名：Analytical Chemistry
• 出版年：2007
• 出版时间：April 15, 2007
• 年：2007
• 卷：79
• 期：8
• 页码：3048 - 3055
• 全文大小：458K
• 年卷期：v.79,no.8(April 15, 2007)
• ISSN：1520-6882

文摘

Single nanopore electrodes and nanopore electrode arrayshave been fabricated using a focused ion beam (FIB)method. High aspect ratio pores (~150-400-nm diameter and 500-nm depth) were fabricated using direct-writelocal ion milling of a silicon nitride layer over a buriedplatinum electrode. This local milling results in formationof a recessed platinum electrode at the base of eachnanopore. The electrochemical properties of these nanopore metal electrodes have been characterized by voltammetry. Steady-state voltammograms were obtained fora range of array sizes as well as for single nanoporeelectrodes. High-resolution scanning electron microscopyimaging of the arrays showed that the pores had truncatedcone, rather than cylindrical, conformations. A mathematical model describing diffusion to an electrode located at the base of a truncated conical pore was developed and applied to the analysis of the electrode geometries.The results imply that diffusion to the pore mouth is thedominant mass transport process rather than diffusionto the electrode surface at the base of the truncated cone.FIB milling thus represents a simple and convenientmethod for fabrication of prototype nanopore electrodearrays, with scope for applications in sensing and fundamental electrochemical studies.