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Title: Structural tuning of nanogaps using electromigration induced by field emission current with bipolar biasing

We report a new method for fabrication of Ni nanogaps based on electromigration induced by a field emission current. This method is called “activation” and is demonstrated here using a current source with alternately reversing polarities. The activation procedure with alternating current bias, in which the current source polarity alternates between positive and negative bias conditions, is performed with planar Ni nanogaps defined on SiO{sub 2}/Si substrates at room temperature. During negative biasing, a Fowler-Nordheim field emission current flows from the source (cathode) to the drain (anode) electrode. The Ni atoms at the tip of the drain electrode are thus activated and then migrate across the gap from the drain to the source electrode. In contrast, in the positive bias case, the field emission current moves the activated atoms from the source to the drain electrode. These two procedures are repeated until the tunnel resistance of the nanogaps is successively reduced from 100 TΩ to 48 kΩ. Scanning electron microscopy and atomic force microscopy studies showed that the gap separation narrowed from approximately 95 nm to less than 10 nm because of the Ni atoms that accumulated at the tips of both the source and drain electrodes. These results show that the alternatelymore » biased activation process, which is a newly proposed atom transfer technique, can successfully control the tunnel resistance of the Ni nanogaps and is a suitable method for formation of ultrasmall nanogap structures.« less
Authors:
; ;  [1]
  1. Department of Electrical and Electronic Engineering, Tokyo University of Agriculture and Technology, Koganei, Tokyo 184-8588 (Japan)
Publication Date:
OSTI Identifier:
22490759
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 1; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ALTERNATING CURRENT; ANODES; APPROXIMATIONS; ATOMIC FORCE MICROSCOPY; ATOMS; CATHODES; CONTROL; ELECTROPHORESIS; FABRICATION; FIELD EMISSION; SCANNING ELECTRON MICROSCOPY; SILICON OXIDES; SUBSTRATES; TEMPERATURE RANGE 0273-0400 K