Batch fabrication of gold-gold nanogaps by E-beam lithography and electrochemical deposition.

We report on the successful development of a well-controlled two-step batch nano-fabrication process to achieve nanometer-size gaps at the wafer scale. The technique is based on an optimized electron-beam lithography process, which enables the fabrication of nanogaps in the range (15 ± 4) nm. Following this first step, the feedback-controlled electrochemical deposition of gold from an aqueous HAuCl4-based electrolyte is applied to further reduce the size of the gap down to about 0.