Nanofabrication of Carbon Nanotubes Assisted with Oxygen Gas

We report the cutting technique of carbon nanotubes (CNTs) assisted with oxygen gas, the cutting procedure occurred in less than 1 minute by a low-energy electron beam inside a field emission scanning electron microscope (FE-SEM). The oxygen gas was regulated by a digital mass flow controller and was injected at 1 sccm from a glass nozzle. It is found that although the total pressure of specimen chamber reached 10^-2Pa, high speed cutting occurs only in the area close to the nozzle. We assume that CNTs are cut only under the low acceleration voltage, because the carbon molecules were easily exited and ionized by the low-energy electron beam. A logo consisting of two letters was assembled with 6 CNTs assisted with cutting process. We think that the cutting inside SEM will be widely used for fabrication, assembly of nanodevices and characterization of nanomaterials.