Observation of Coulomb Blockade Effects in AFM-machined Tunnel Junctions

✍ Scribed by Br�ckl, H.; Rank, R.; Vinzelberg, H.; M�nch, I.; Kretz, L.; Reiss, G.

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 280 KB
• Volume: 25
• Category: Article
• ISSN: 0142-2421
• DOI: 10.1002/(sici)1096-9918(199706)25:7/8<611::aid-sia286>3.0.co;2-2

✦ Synopsis

Narrow metal wires patterned on Si(100) wafers by conventional e-beam lithography have been subsequently mechanically modiÐed with an atomic force microscope. Using the line resistance as an indicator of the progress of the modiÐcation, narrow insulating gaps were successfully machined into the lines. The gap widths depend both on the metal the lines are made of and on the tips used for machining ; typically they were between 50 and 100 nm. Subsequently, these gaps were Ðlled by small amounts of metal, using again an in situ control by resistance measurements during the deposition of the metal. In this way, we obtained small junctions in the lines with metallic islands located in the gap area. Measurements of the current-voltage characteristics of these devices showed a pronounced coulomb blockade with a charging energy of 2 mV.

1997 by John