Fabrication of carbon nanotube tips for scanning tunneling microscopy by direct growth using the microwave plasma-enhanced chemical vapor deposition

Abstract

Carbon nanotube (CNT) tip for scanning tunneling microscopy (STM) is fabricated directly on a tungsten tip by microwave plasma-enhanced chemical vapor deposition (MPECVD). The reduction of the density of plasma ions directed to the apex of the tungsten tip suppresses the sputtering effect, and makes a successful fabrication of CNT tip. The length of grown CNTs can be well controlled below 1 μm by growth time. The grown CNTs have bamboo-like structure with a catalyst attached on the top, as confirmed by transmission electron microscopy (TEM). Demonstrative observation of graphite surface on an atomistic scale is performed by the fabricated CNT tips. © 2006 The Surface Science Society of Japan.