Fabrication of Four-Probe Fine Electrodes Using Scanning-Probe Nanofabrication

We have fabricated four-probe Pt electrodes on a sapphire substrate by scanning-probe nanofabrication and reactive ion beam etching. Surface roughness, gap width and height of the fabricated electrodes were 0.3 nm, 150 nm and 4 to 5 nm, respectively. In order to test the quality of the fine electrodes, we evaluated the current through a multi-walled carbon nanotube (MWNT) placed on the electrodes. The measured two-probe resistance of the MWNT was 130 kΩ which included the contact resistance, while the leakage resistance was larger than 1 TΩ.