Synthesis of regular nano-pitched carbon nanotube array by using nanosphere lithography for interconnect applications

In this paper, we report a method based on nanosphere lithography technology for the synthesis of nano-pitched vertically aligned multi-walled carbon nanotube array. A monolayer of polystyrene nanospheres with diameter of 650 nm was coated on silicon oxide layer to create hexagonally arranged patterns. A metal layer, which acted as a catalyst for carbon nanotube growth, was deposited on the patterns by e-beam evaporation method. Nano-sized metallic patterns were formed by removing the polystyrene nanospheres. Uniform CNT arrays with pitch of 800 nm were successfully synthesized from the metallic patterns by plasma enhanced chemical vapor deposition. Using nanosphere lithography, the pitch of the single CNT array can be well-controlled. Therefore, the as-grown CNTs have potential applications in advanced interconnects technology and other nano applications.