AVS 53rd International Symposium
    Plasma Science and Technology Tuesday Sessions
       Session PS3-TuP

Paper PS3-TuP3
Controlling the Fluxes of Carbon Supply for Carbon Nanotube Growth in CH@sub 4@/H@sub 2@ Plasma

Tuesday, November 14, 2006, 6:00 pm, Room 3rd Floor Lobby

Session: Advanced Plasma Deposition Poster Session
Presenter: A. Okita, Hokkaido University, Japan
Authors: A. Okita, Hokkaido University, Japan
Y. Suda, Hokkaido University, Japan
A. Ozeki, Hokkaido University, Japan
A. Oda, Nagoya Institute of Technology, Japan
J. Nakamura, Tsukuba University, Japan
K. Bhattacharyya, Hokkaido University, Japan
H. Sugawara, Hokkaido University, Japan
Y. Sakai, Hokkaido University, Japan
Correspondent: Click to Email
Carbon nanotubes (CNTs) exhibit unique properties such as high chemical stability and current density. We are interested in LSI applications of CNTs utilizing their electronic properties. However, LSI technology demands the precisely control of CNTs growth with regard to placement, length, diameter and number density. We have focused on the growth speed of CNTs in order to fulfill the above demands. The purpose of this paper is to investigate the growth speed of CNTs by controlling the fluxes of carbon source. We have used plasma-enhanced chemical vapor deposition (PECVD) for CNT growth.@footnote 1@ PECVD can effectively decompose gas molecules and produce the precursors for CNTs such as ions and radicals. In this experiment, Al@sub 2@O@sub 3@/Fe/Al@sub 2@O@sub 3@ (1/1/1 nm) thin films were used as catalyst (Fe)/support (Al@sub 2@O@sub 3@) materials, and vertically-aligned CNTs were obtained using CH@sub 4@/H@sub 2@ plasma. The degree of catalyst activities and oxidation states were observed by X-ray photoelectron spectroscopy (XPS), and CNTs obtained were evaluated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM).@footnote 1,2@ In addition, CH@sub 4@/H@sub 2@ plasma was simulated by one-dimensional fluid model to analyze the correlation with the CNTs growth and plasma gas phase.@footnote 1@ This simulation results correlating to experimental condition enable us to predict the fluxes of carbon-containing species onto the substrate. As the results, average length of CNTs became shorter by applying positive DC bias to the substrate. We will discuss the effect of bias voltage on CNT growth speed and compare the simulation results in terms of the difference of fluxes of carbon-containing species. @FootnoteText@@footnote 1@A. Okita, et al., J. Appl. Phys. 99 (2006) 014302, @footnote 2@A. Okita, et al., Jpn. J. Appl. Phys., (accepted).