Rapid growth of nanostructure on tungsten thin film by exposure to helium plasma

A fiberform nanostructure was synthesized by exposing high-density helium plasma to a 100 nm thick tungsten thin film in the linear plasma device NAGDIS-II. After helium plasma exposure, the cross-section of samples was observed by a scanning electron microscope, transmission electron microscope, and focused ion beam scanning electron microscope. It is shown that the thickness of the nanostructured layer increases significantly for only a short irradiation time. The optical absorptivity remains high, even though it is exposed to helium plasma for a short time. The usage of the thin film can shorten the processing time for nanostructure growth, which will be beneficial for commercial production.