Abstract
Generally single wall carbon nanotubes (SWNTs) grow in the vertical direction on the catalytic metal plane. Therefore we deposited an Al layer of 10 nm on the catalytic layer by sputtering. The Al layer plays the role of a barrier to prevent vertical growth of the SWNTs effectively. In addition, the size of the gap between the pads and the sharp of the pads are the key parameters for determining the chemical vapor deposition (CVD) growth duration for successfully bridging the pads by individual SWNT. To determine the electric properties of the SWNTs contacts, detailed current-voltage (I-V) measurements were performed on sample with the different SWNT connections. Some I-V curves are linear, suggesting metallic behavior; others exhibit nonlinear and a low conductance region develops around V=0. By combining the advantages of in-situ carbon nanotube growth technology and the lithography technology, we have realized the top-gate single wall nanotubes field effect transistors (SWNT-FETs) with individual device operation. We have succeeded in observing ambipolar and generalized p-type transistor operation in variable band gap semiconducting SWNT channels. In summary, the results indicates that the top-gate structure can be operated and demonstrate the potential of SWNT for the future complementary electronic.