IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Nanotubes: Science and Applications Topical Conference Tuesday Sessions
       Session NT-TuP

Paper NT-TuP7
Characteristic of Carbon Nanotube Tip in UHV-STM

Tuesday, October 30, 2001, 5:30 pm, Room 134/135

Session: Poster Session
Presenter: K. Ojima, Toyota Technological Institute, Japan
Authors: K. Ojima, Toyota Technological Institute, Japan
M. Ishikawa, Toyota Technological Institute, Japan
M. Yoshimura, Toyota Technological Institute, Japan
K. Ueda, Toyota Technological Institute, Japan
Correspondent: Click to Email
Recently much attention is paid to carbon nanotube (CNT) because of its unique structural and electric properties. Field emitter, nano-tweezers and probe in scanning probe microscopy are expected for future application using CNTs, and have been extensively studied. In terms of the last application, most of reports are devoted to in the fields of atomic force microscopy. However, there is few study to use CNT in scanning tunneling microscopy (STM). Here we report on the application of CNT for STM probes in ultrahigh vacuum in order to investigate its capability. CNTs are attached to the tungsten tip using a new preparation method we recently proposed [unpublished]. The presence of CNT at the apex of the tip is confirmed before and after the STM experiment by scanning electron microscope. Before STM measurement, the contamination on the tip is removed by radiant heating. The Si(100)2x1 surface is used as the reference specimen, as is prepared by conventional method. STM images of Si(100)2x1 surface using CNT tip reveal individual silicon atoms in dimer units. However the image is a little bit vaguer than the case without CNT. This is probably related to the electric property of CNT. In order to image the surface structure clearly, the sample bias voltage and the tunneling current should be set at larger than 1.5V and lower than 0.1nA, respectively, which is apparently different condition from the tungsten tip without CNT. It is also noted that in the images obtained by CNT, no ghost such as double tip effect is observed. The voltage dependence of STM images will be presented in order to clarify the electric property of the CNT tip.