Directed assembly of carbon nanotube electronic circuits

We report on a method for directed assembly of integrated carbon nanotube circuits using selective area chemical vapor deposition on prepatterned catalyst electrodes. The circuits consist of a multiwall carbon nanotube bridging a pair of electrodes, forming a metal/carbon nanotube/metal structure. Electron-beam lithography was used to define electrode sets separated by a desired distance on a SiO₂/Si substrate. Following metal evaporation and lift-off, molecular jet chemical vapor deposition was used for selective growth of carbon nanotubes on the catalyst electrodes. The carbon nanotubes eventually form a bridge between nearby electrodes consisting of one, or in some cases more than one multiwall nanotubes. The room temperature resistance of the carbon nanotube circuits measured at the electrode leads is typically less than 100kΩ. The carbon nanotube circuits were characterized by electronic transport measurements in the temperature range from room temperature to 2 K.