Fabrication of nanogaps by a progressive electromigration technique using wires of various thicknesses
(a) I–V plot of the onset of electromigration, which is indicated by a flat region in the current. The inset shows a SEM image of a gold wire with a width of 30 nm. (b) I–V curve of the completed electromigration process for a gold wire with width of 70 nm. The wire failed at 0.5 V. The inset shows the SEM image of the nanogap resulting from this electromigration. The scale bar in the SEM images is 100 nm.
SEM image of (a) 30 nm (b) 45 nm, and (c) 60 nm width wires with gaps of 2–3 nm.
(Color online) Histogram showing the number of samples tested and the size of the gap formed. The inset shows a histogram of 2–3 nm gaps as a function of wire thicknesses. (Note: The average wire widths resulting from e-beam lithography were in the range 40–65 nm.)
(Color online) I–V curve obtained immediately after formation of a nanogap. The dashed line is the experimental curve and the solid line is the Simmons’ fit. The parameters from the fit are 1 nm gap size, 0.18 eV barrier height and 8.49 × 10−17 m2 junction area.
(Color online) I–V curve before (dashed line) and after (solid line) deposition of Au nanoparticles in the gap.
(Color online) I–V (solid line) and dI/dV (dotted line) for a nanogap formed by electromigration. The measurement was performed in vacuum and at room temperature.
Summary of the control experiments performed at a ramp rate of 1 mV/s.
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