Directed assembly of highly-organized carbon nanotube architectures

Abstract

A method of controllably aligning carbon nanotubes to a template structure to fabricate a variety of carbon nanotube containing structures and devices having desired characteristics is provided. The method allows simultaneous, selective growth of both vertically and horizontally controllably aligned nanotubes on the template structure but not on a substrate in a single process step.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS [0001] The present application is a Divisional of U.S. application Ser. No. 10 / 361,640, filed Feb. 11, 2003, which claims benefit under 35 U.S.C. § 119(e) of U.S. provisional application 60 / 356,069, filed Feb. 11, 2002 and 60 / 385,393, filed Jun. 3, 2002, both of which are incorporated herein by reference in their entirety.STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT [0002] The U.S. Government may have certain rights in this invention pursuant to grant number N00014-00-1-2050 from the Office of Naval Research.BACKGROUND OF THE INVENTION [0003] The present invention relates generally to carbon nanotubes and more particularly to selective growth of carbon nanotubes on template materials. [0004] It is likely that future devices containing organized structures of various functional materials with new properties will be built from nanoscale building blocks. These nanoscale building blocks can be produced by a variety of syn...

AI Technical Summary

Problems solved by technology

However, the present techniques used to controllably build organized architectures of nanotubes with predetermined orientations have several deficiencies.

However, this technique requires deposition and patterning, usually in separate processing steps, of catalyst material, typically in nanoparticle assemblies or thin film forms, which complicates the nanotube fabrication method.

This also does not allow growth of nanotubes in more than one preselected orientation at different locations in a controllable fashion.

While growth of vertically aligned nanotubes on planar substrates by CVD has been reported extensively, obtaining nanotubes that are exclusively oriented parallel to the substrate in predetermined orientations has been more difficult.

However, these approaches require pre-deposition and pre-patterning of nanoscale catalyst particle assemblies.

Also, the probability of nanotubes bridging across different catalyst islands is difficult to predict and control.

However, these methods are also complicated, and are difficult to scale (e.g., create them reproducibly on an 8 inch Si wafer) and to control, for developing devices for applications.

Moreover, in these cases the nanotubes are not rooted to the substrate (i.e. they are just lying on them, and hence not very robust).

However, as can be seen in FIG. 4 of the Z. J. Zhang et al. article, while roughly vertical and horizontal nanotubes were simultaneously grown on the template structures, it was not possible to controllably align nanotubes during growth in a direction perpendicular to the silica template structure surfaces.

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