AVS 51st International Symposium
    Nanometer-scale Science and Technology Tuesday Sessions
       Session NS-TuM

Paper NS-TuM2
Growth of Arrays of mm Long, Straight Single-Walled Carbon Nanotubes

Tuesday, November 16, 2004, 8:40 am, Room 213D

Session: Nanotube Processing and Composite Materials
Presenter: Z. Yu, UC Irvine
Authors: Z. Yu, UC Irvine
S. Li, UC Irvine
P. Burke, UC Irvine
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In this work, we demonstrate the growth of arrays of 1.5 mm long, straight single walled nanotubes fabricated using a single furnace with methane and H2 as the feedstock. Recently Huang et al[1] have fabricated 3.7 mm long single walled carbon nanotubes using a two-furnace, dual temperature growth system with CO and H2 as the feedstock. Our work shows arrays of long, straight nanotubes can be grown in a single furnace system. Using a home-built CVD system based on a 3 inch Lindberg furnace, we have synthesized long, straight nanotubes using CVD. The catalysts were prepared as follows: First, a lithographically patterned Ti(50 nm)/Au(200 nm) metallization layer is deposited and patterned using e-beam evaporation onto a Si wafer. Next, an aqueous solution containing nanoparticle catalyst is deposited and lifted off onto only the patterned Au. The growth procedure was as follows: First, the sample was heated to 900 C in Ar. Next, H2 was flowed for 10 minutes. Next, methane/H2 mixture was flowed for 15 minutes to activate the growth.Post-growth characterization was carried out with SEM. AFM growth from nanotubes grown under similar conditions in our lab yielded diameters of 1.5 nm. The growth results indicate an aligned array of nanotubes (6) with pitch of 50 microns and length of at least 200 microns. 3 of the 6 nanotubes were 1.5 mm in length. The growth of the longer nanotubes was terminated only by the presence of a neighboring catalyst site. With properly designed catalyst geometries with room to grow, cm long single walled nanotube growth should be possible. In the future it should be possible to grow 2d arrays by rotating the wafer and carrying out a second growth run. By engineering the nanotube pitch, ultra-dense electrical circuitry could be fabricated. @FootnoteText@ [1] S. Huang, B. Maynor, X. Cai, J. Liu, â?oUltralong Well-Aligned Single-Walled Carbon Nanotube Architectures on Surfacesâ?, Advanced Materials, vol. 15, pp. 1651-1655, 2003.