### Session U27: Focus Session: Carbon Nanotubes: Growth

8:00 AM–11:00 AM, Thursday, March 24, 2005
LACC Room: 501C

Chair: Vera Sazanova, Cornell University

Abstract ID: BAPS.2005.MAR.U27.1

### Abstract: U27.00001 : Critical silicon dioxide thickness for CVD growth of single-walled carbon nanotubes

8:00 AM–8:12 AM

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#### Authors:

J. M. Simmons
Matthew S. Marcus
O. M. Castellini
(Department of Physics, University of Wisconsin - Madison)

R. J. Hamers
(Department of Chemistry, University of Wisconsin - Madison)

M. A. Eriksson
(Department of Physics, University of Wisconsin - Madison)

Chemical vapor deposition (CVD) has shown remarkable control over the efficient and directed assembly of single-walled carbon nanotubes, making CVD a primary growth method for device applications. Due to the high temperatures involved in CVD, the chemical compatibility between the substrate, feedstock, and catalyst must be understood. Using x-ray photoelectron spectroscopy (XPS), we have studied the evolution of the chemical state of an iron nitrate catalyst during the initial temperature ramp of a standard CVD process. Heating the catalyst on clean silicon or on silicon with a native oxide leads to the formation of a silicide at 800~$^{o}$C, inhibiting single-walled nanotube growth. By 900~$^{o}$C, a typical growth temperature, all of the iron catalyst has been incorporated into the silicide. Thicker silicon oxide layers, on the order of 10~nm, effectively prevent silicide formation, enabling high yield growth.

To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2005.MAR.U27.1