Atom-size gaps and contacts between electrodes fabricated with a self-terminated electrochemical method

摘要

We describe a method to fabricate atomic-scale gaps and contacts between two metal electrodes. The method uses a directional electrodeposition process and has a built-in self-termination mechanism. The final gap width and contact size are preset by an external resistor (R_(ext)) that is connected in series to one of the electrodes. If 1/R_(ext) is chosen to be much smaller than the conductance quantum (G_(0)=2e~(2)/h), a small gap with conductance determined by electron tunneling is formed. If 1/R_(ext) is comparable or greater than G_(0), a contact with conductance near a multiple of G_(0) is fabricated.