Process investigation of the electrochemical fabrication of Au tunnel junction with atomic-scale

A stable Au tunnel junction Was fabricated electrochemically with the thin gold wire and the process was investigated in details. It is found that Au tunnel junction is not easy to be obtained by direct electrochemical etching of Au wire due to the mechanical stress. However, it's easy to control the process of electrochemical deposition on a preformed Au electrode pair as well as its reverse process-etching with addition of chloiroauric acid in solution. The existence of An ions may cause somewhat instability of the junction, while in hydrochloric acid solution, the process is under control and the Au tunnel junction is stable.