Reduced contact resistance between an individual single-walled carbon nanotube and a metal electrode by a local point annealing

The achievement of low-resistance contact is a key requirement for carbon-electrode electronics. In this study, we have obtained contacts with very low resistance between an individual single-walled carbon nanotube (SWNT) and palladium (Pd) electrodes using electric-current-induced Joule heating without destroying the field effect transistor device that these form. The SWNT is deposited onto Pd electrodes prepatterned on a SiO2/Si substrate, through which an electrical pulse is applied for a microsecond duration. As a result, the source-drain current through the SWNT is greatly increased owing to the elimination of tunnelling barriers between the SWNT and the electrodes. In the case of semiconducting SWNTs, the Schottky barrier is estimated to increase slightly after pulse annealing in some cases, resulting in a relatively high resistance and asymmetrical current-voltage characteristics.