AVS 51st International Symposium
    Nanometer-scale Science and Technology Monday Sessions
       Session NS-MoM

Paper NS-MoM9
Environmental Effects on Double Wall Carbon Nanotube Field Effect Transistors

Monday, November 15, 2004, 11:00 am, Room 213D

Session: Carbon Nanotubes-Electrical Properties
Presenter: D. Kang, Samsung Advanced Institute of Technology, Korea
Authors: D. Kang, Samsung Advanced Institute of Technology, Korea
W. Park, Samsung Advanced Institute of Technology, Korea
J.R. Kim, Chonbuk National University, Korea
C.J. Lee, Hanyang University, Korea
J.J. Kim, Chonbuk National University, Korea
Correspondent: Click to Email
With the rise of nanotechnology, there are many new interesting properties induced by their dimensions and geometries. One of the these is large surface area due to their unique geometric shapes such as nanotube and nanowires. For device applications harnessing these materials, large surface area effects on electrical properties should be investigated for a better understanding of nano devices. Double Wall Carbon Nanotube(DWCNT)s could be the best material to investigate the effects because their small band gap should enhance the response to their environments. In this letter, we fabricate DW-CNTFETs in a back-gated structure and investigate environment effects on the electrical properties of DW-CNTFETs in comparison to SW-CNTFETs. Purified double wall CNTs (DWCNT) were suspended in a solvent and spin coated on SiO2 grown on a heavily doped Si substrate. Scanning Probe Microscopy (SPM) located the position of the wires on the substrate. After the pattern for metals contacts were generated by electron beam lithography, metal electrodes were defined by lift-off process after 100nm Pd metal evaporation. We find that DW-CNTFET shows conversion from unipolar to bipolar in vacuum. However, the SW-CNTFET does not show the conversion in the measurement conditions we used in this study. In ambient air, both CNTFETs shows large hysteresis by electron trapping at slow states. We believe that water adsorption on the tube plays an important role for ambipolar conversion.