Protected nanoelectrodes of two different metals with 30nm gapwidth and access window

Top‐Down Approaches to the Fabrication of Nanopatterned Electrodes

“…Waser and coworkers [47] reported the use of two EBL steps to create nanoelectrodes with nanogaps on silicon wafers. On each chip, 30 nanoelectrodes representing 15 pairs of nanogaps were fabricated.…”

“…The nanoelectrodes were characterized by capacitance measurements in sulfuric acid, which was used to study the capacitance. Additionally, the electrodeposition of copper ions on the nanogap electrodes was demonstrated as a promising strategy to narrow the gap down to a few Angstroms for contacting small clusters and tailored molecules in metal-molecule-metal hybrid assemblies [47].…”

“…The former case reports detection levels down to 1 fM of DNA. Some reports have also been made on the electrodeposition of metals in order to narrow the gaps between the electrodes even down to atomic scale dimensions, where possible applications include the contacting of small clusters and tailored molecules in metal-molecule-metal hybrid assemblies [47], and investigation of the electrical transport properties of various nanomaterials and organic molecules [53].…”

Electrochemical characterization of nano-sized gold electrodes fabricated by nano-lithography

“…The currently most commonly used methods involve stretching a glass capillary containing a Pt wire of micrometer diameter, until a desired outer diameter is reached for the glass [6][7][8][9], or etching a wire down to an ultrafine tip and coating all but the apex of the metal with an insulating polymer [10,11]. Lithographical fabrication was introduced by preparing interdigitated arrays of electrodes [12,13] and allows the design of individual nanoelectrodes patterned on top of a silicon oxide surface [13][14][15]. While the microelectrodes based on sealed wires are being produced with very small surface areas, there is no accurate, in situ control over the actual electrode surface area during manufacture and it has to be determined after fabrication.…”

“…Moreover, the success rate of such a delicate process is quite low [1,6,7,16]. On the other hand, lithographically produced electrodes require fabrication expertise and electrochemical measurements on them have been troubled by parasitic capacitance [3,14,15].…”