AVS 53rd International Symposium
    Nanometer-scale Science and Technology Wednesday Sessions
       Session NS+NM-WeA

Paper NS+NM-WeA1
Direct Deposition of Ordered Polymer Nanostructures in UHV via thermal Dip-Pen Nanolithography

Wednesday, November 15, 2006, 2:00 pm, Room 2016

Session: Nanolithography and Patterning
Presenter: P.E. Sheehan, Naval Research Laboratory
Authors: P.E. Sheehan, Naval Research Laboratory
M. Yang, Naval Research Laboratory
A.R. Laracuent, Naval Research Laboratory
B.A. Nelson, Georgia Tech
W.P. King, Georgia Tech
L.J. Whitman, Naval Research Laboratory
Correspondent: Click to Email
In thermal Dip Pen Nanolithography (tDPN) a heated atomic force microscope cantilever controls the deposition of a solid ink, acting like a nanoscale soldering iron. tDPN has several advantages over conventional DPN. Control over writing is greatly improved deposition may be turned on or off and the deposition rate easily changed without breaking contact with the surface. In addition, imaging with a cool tip does not appear to contaminate the surface, thereby allowing in situ confirmation of the deposited pattern. Finally, tDPN can deposit a range of materials that are immobile at room temperature from semiconductors to insulators to metals. Thermal DPN is particularly suited to the deposition of polymers. To date, mylar, MEH-PPV, and poly(3-dodecylthiophene) [PDDT] have all been successfully deposited. PDDT is of particular interest as a conducting polymer with great potential for use in organic electronic devices. Using tDPN, well-ordered PDDT nanostructures have been deposited on silicon oxide and gold surfaces with layer-by-layer thickness control. By adjusting the tip heating power and the writing speed, we can vary the polymer thickness from a single monolayer (~2.6 nm) to tens of monolayers with lateral dimensions below 100 nm. Moreover, the morphology of the nanostructure suggests that the polymer strands are aligned along the path of the AFM tip. Unlike conventional DPN inks, the low vapor pressure of solvent-free polymers allows deposition in Ultra High Vacuum (UHV). We have deposited in UHV single monolayers of highly-ordered PDDT nanostructures on clean Si(001)-(2x1). The electronic and crystallographic properties of these structures will be discussed.