Fabrication Of Carbon Nanotube–Graphene/ Copper-Nickel Hybrid Structure

Carbon nanotubes have excellent properties due to their unique geometrical structure,and have wide application prospects in microelectronic devices.However,carbon nanotubes and metal electrode contact has a relatively high schottky barrier corresponding to a high contact resistance,which seriously affects the performance and application of carbon nanotubes device.The lattice structure of graphene is similar to that of carbon nanotubes,with high mobility and zero energy bandwidth,and thus can serve as the ideal electrode for carbon nanotube devices.With graphene growth on copper/nickel double layer film,a carbon nanotube-graphene/copper-nickel hybide structure was prepared in this thesis.Thefabrication process of the hybidestructure was studied.The electricalconductivity and microstructure of the carbon nanotube-graphene/copper-nickel hybide structure were analyzed.The carbon nanotube-graphene/copper-nickel hybrid was prepared on the silicon substrate with oxide layer.First,the copper-nickel hybrid electrode was obtained by semiconductor fabrication process mainly including photolithography,sputtering,lift-off;Then dielectrophoresis(DEP)technique was used to assemble carbon nanotubes between electrodes;Last,the graphene was grown on the electrode equipped with carbon nanotubes by chemical vapor deposition and the carbon nanotubes-graphene /copper-nickel hybrid structures were obtained.The DC resistances of the Carbon nanotubes-graphene/ copper-nickel hybrid structureand carbon nanotubes /metal structurewithoutgraphene grown were measured.The results showed that the resistance between the electrodes was reduced from several mega-ohms to several tens of kilo-ohms with graphenegrowth,and the carbon nanotubes in contact with graphene/copper-nickel hybrid electrodesare stable.The microstructures of the hybridstructures were analyzed by means of SEM,energy dispersive spectrometer(EDS)and Raman spectroscopy.The results showedthatcertain copper atoms in the composite structure diffused along the carbon nanotubes.The defects of carbon nanotubes induced duringDEP in the hybridstructure were improved after graphene growth.