Decrease the OFF state current of carbon nanotube field effect transistors via continuous repeated gate sweeping

Continuous repeated gate sweeping incorporated with substrate etching step is utilized to decrease the OFF state current in carbon nanotube field effect transistor (CNT-FET) devices with bundled carbon nanotubes. In particular, the effects of continuous repeated gate sweeping on transfer characteristics of CNT-FETs are examined. The etching step creates suspension in CNT-FETs at the contacts with metal electrodes as well as makes metallic CNTs dramatically burnt off by electrical current. By repeating sweeping, source-drain current gets lower and lower. This will eventually lead to the OFF state current less than 2 nA. Defects in the lattice of CNTs introduced by multiple gate sweeping could be the reason for this phenomenon. Contribution from possible force of electric field is also considered.