A Novel Fabrication Method for Pristine Suspended Carbon Nanotube Devices

ORAL

Abstract

A simple and scalable method has been developed to fabricate suspended carbon nanotube (CNT) field effect transistors using as-grown CNTs without subsequent chemical processing.\footnote{\textit{V. K. Sangwan} et al, APL \textbf{93}, 113112 (2008)} A printing process is used to transfer CVD-grown CNTs onto specially configured electrode (Au) sets fabricated on SiO$_{2}$. The versatility of the technique is demonstrated by controlling the number of suspended CNTs per device, and by re-using the same electrode set multiple times to produce the desired device characteristics. The quality of suspended CNTs is characterized by electrical transport as well as 1/f noise measurements. Standard resist-processed CNTs on SiO$_{2}$ substrates show p-type behavior and strong hysteresis associated with doping by the SiO$_{2}$ surface and charge trapping in the SiO$_{2}$, respectively. In contrast, suspended CNTs show ambipolar behavior with negligible hysteresis. Low frequency noise measurements on suspended CNT show 1$/f$ behavior with Hooge's constant 2.6 x 10$^{-3}$, around 20 times less than that of CNTs lying on SiO$_{2}$, consistent with reduced effect of the SiO$_{2}$ charge traps, responsible for the bulk of the noise in CNTs on SiO$_{2}$.

*Work supported by the Laboratory for Physics Sciences. The SEFs of the UMD NSF-MRSEC were used in this work.

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Authors

  • Vinod Sangwan

    • Laboratory of Physical Sciences (LPS), CNAM,, and DOP, UM
    • University of Maryland

  • Vincent Ballarotto

    • University of Maryland

  • Michael Fuhrer

    • CNAM and the DOP, UM

  • Ellen Williams

    • University of Maryland, College Park
    • Department of Physics and University of Maryland Materials Research Science and Engineering Center, University of Maryland, College Park, MD 20742
    • University of Maryland
    • LPS, CNAM, and the DOP, UM
    • Physics Department, University of Maryland, College Park, MD 20742
    • Materials Research Science and Engineering Center, Center for Nanophysics and Advanced Materials, Dept of Physics, Univ. of Maryland, College Park, MD
    • University of Maryland College Park
    • Dept. of Physics, U. of Maryland - College Park
    • Department of Physics and Center for Nanophysics and Advanced Materials, University of Maryland, College Park, MD 20742-4111, USA