Friday, August 31, 2007

US Patent 7262991 - Nanotube/nanocrystal non-volatile memory

Carbon nanotubes and various metal nanocrystals have both been suggested and implemented in experimental electronic designs. This patent from Intel uses both nanomaterials to achieve an improved high density flash memory. Claim 1 reads:

1. An apparatus comprising: a substrate; a dielectric over the substrate; a carbon nanotube in the dielectric to form a nanotube channel; a source electrode and drain electrode on respective sides of the nanotube channel; metal nanocrystals adjacent to the nanotube channel and between the source electrode and the drain electrode to form an array of discrete floating gates adjacent the carbon nanotube; a tunnel oxide separating the nanocrystals and the carbon nanotube; a gate electrode over the nanocrystals; and a control oxide separating the gate and the nanocrystals.

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US Patent 7262515 - Molecular perpetual motion machine

While I'm not certain whether this patent represents enabled technology or not, it certainly sounds like something that is not exactly in agreement with the second law of thermodynamics. Basically the patent teaches using impacts of molecules of a gas on nanoscopic paddles to simultaneously cool a gas formed from the molecules and convert the mechanical energy from the paddle gained by the impact into a more useful form. However, this would seem to be equivalent to transforming a random form of energy (such as heat) to a more ordered form of energy (such as stored chemical energy) which is not exactly explainable by modern thermodynamics (as far as I know). The claims were not questioned under the utility or enablement requirements of patentability during prosecution though. In any case, claim 1 reads:

1. A system immersed in a working substance having a plurality of molecules, said system comprising: a base member; a source of heat for heating said working substance; and a plurality of nanometer scale assemblies that convert energy from one form to another coupled to said base member, each of said nanometer scale assemblies comprising: a molecular impact mass that reduces the velocity of said molecules that impact said impact mass, wherein said impact mass is restrained to move within a predetermined range of distance and the movement of said impact mass in one direction is limited.


Thursday, August 30, 2007

US Patent 7262501 - Thin film semiconductor formed from p-type and n-type nanowires

Nanosys is one of three companies leading the way in alternative approaches to electronics (the others being Nantero and Hewlett Packard). The approach of Nanosys is to premanufacture semiconductor nanowires which are predoped to be n-type or p-type and then align the nanowires on a substrate to form electronic devices. The advantage of this approach is that it opens the door to many different substrates other than silicon (such as flexible and/or biocompatible material) from which to form sensors, photovoltaics, electronics, etc. In addition, lower cost fabrication can be achieved using printing technologies rather than the high temperature/low pressure conditions of modern fabs. This patent is directed to methods of making such nanowire electronics. Claim 1 reads:

1. A method of making a thin film for use in one or more semiconductor devices, comprising: (A) forming a first plurality of nanowires that are p-type; (B) forming a second plurality of nanowires that are n-type, wherein said forming comprises doping said second plurality of nanowires with an n-type dopant; (C) depositing the first plurality of nanowires on a first region of a substrate and second plurality of nanowires onto a second separate, non-overlapping region of the substrate to form a thin film of nanowires that includes n-type and p-type nanowires; and (D) allowing the mixture of n-type and p-type nanowires to become immobilized on the substrate, whereby the thin film of nanowires exhibits characteristics of both n-type and p-type nanowires.


US Patent 7262266 - SWCNT block co-polymers

Block copolymers have an interesting property of self assembly used to form periodic structures on the nanoscale. This patent from Rice University teaches using single walled carbon nanotubes as a functional component of block co-polymers. Claim 1 reads:

1. A block copolymer comprising: a) a first block material comprising short single-wall carbon nanotubes (SWNTs); and b) a second block material comprising a rigid rod aromatic polymer.

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Wednesday, August 29, 2007

US Patent 7261941 - Carbon nanohorn with directed tip

Carbon nanotubes aggregates having conical tips are referred to as carbon nanohorns. This patent from NEC teaches a carbon nanohorn with a acute angle directed tip for improved uses in applications such as carbon based electron emission. Sumio Iijima, who is credited as having first recognized carbon nanotubes in 1991, is noted as a co-inventor. Claim 1 reads:

1. An acute closed tip, multi-wall carbon nanotube radial aggregate, which includes a plurality of acute tip, multi-wall carbon nanotubes which each have one sharp, acute angled-end and are radially aggregated with the acute tip portion thereof being disposed outward.

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US Patent 7261940 - Core/shell nanoparticle with magnetic/optical properties

There have been numerous applications exploiting both the magnetic properties and optical properties of nanostructures such as ultrahigh density magnetic storage using nanomagnets and bio-tagging using quantum dots. This patent form Los Alamos National Labs teaches the formation of a hybrid core/shell nanoparticle exploiting both magnetic and optical effects of nanomaterials useful for such applications as magnetically controlled optical emission. Claim 1 reads:

1. A composite nanoparticle comprising: a core of a material selected from the group consisting of a magnetic material and an inorganic semiconductor; and, a shell of a material selected from the group consisting of an inorganic semiconductor and a magnetic material, wherein said core and said shell are of differing materials and said composite nanoparticle is characterized as having multifunctional properties including magnetic properties from said magnetic material and optical properties from said inorganic semiconductor material.

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Tuesday, August 28, 2007

US Patent 7261871 - CNT fabrication using transition metal complexed alkyne

Chemical vapor deposition is a favored method of manufacturing carbon nanotubes in sizable quantities and typically involves flowing a carbon containing gas at high temperatures over a catalyst containing substrate. This patent from the University of California proposes heating transition metals with alkynes (hydrocarbons having at least one triple bond between two carbons) as an alternative method with a lower temperature range than CVD methods.

1. A method of preparing carbon nanotubes, comprising heating a precursor comprising a transition metal complexed alkyne in a sealed vessel to temperatures between C. and C.

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US Patent 7261352 - Nanotweezers with control electrode

Manipulation of individual atomic and molecular particles was achieved with the scanning tunneling microscope and atomic force microscope in the 1980's and 1990's . More recently the development of nanotweezers using electrostatic actuation of opposing carbon nanotubes has allowed for more effective grabbing and holding of molecular objects. However, when grabbing molecules exhibiting electrically conductivity the nanotweezers may be shorted out. This patent from Samsung teaches an improved configuration that adds a control electrode so that the nanotubes forming the nanotweezers may be held at a common polarity. Claim 1 reads:

1. An apparatus for gripping nano-scale objects, the apparatus comprising: a probe including a base portion and a terminal portion; first and second nanotubes secured to the base portion of the probe, each of the first and second nanotubes including a protruding portion which extends past the base portion and the terminal portion of the probe; first and second electrodes formed on the base portion of the probe, the first and second electrodes being electrically connected to the first and second nanotubes, respectively; a third electrode disposed on the terminal portion of the probe; and a control circuit which is electrically connected to the first, second and third electrodes and applies a voltage to the first, second and third electrodes so that the first and second nanotubes are charged to a first polarity and the third electrode is charged to a second polarity opposite to the first polarity thereby causing the protruding portions of the first and second nanotubes to close due to an electrostatic force generated between the first and second nanotubes and the third electrode.

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Thursday, August 23, 2007

US Patent 7259903 - Optical switching using carbon nanotube array

Joseph Crowley from Ambit Corp. was early to recognize the benefits of carbon nanotubes in optical and antenna applications and has several basic patents in these areas. This is one of a series of patents to Ambit Corp. with priority to 1997 and appears to be fairly basic to the use of carbon nanotubes in optical switching. Claim 1 reads:

1. A method of using a carbon nanotube assembly, comprising: growing a signal responsive array of nanotubes on a substrate; receiving an electromagnetic signal by said array of nanotubes grown on said substrate; biasing at least one of said nanotubes in said array of nanotubes, with a further signal; and switching said electromagnetic signal received by said carbon nanotubes relative to said array of nanotubes on said substrate.

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Wednesday, August 22, 2007

US Patent 7259443 - Thermal transfer using a nanoparticle layer

Printing methods such as inkjet and imprinting are growing in popularity as tools for surface processing used in semiconductor and MEMS fabrication. This patent from E.I. du Pont teaches the formation of a thermal transfer media for such purposes using nanoparticles as high dielectric material. Claim 1 reads:

1. An article, comprising: a. a transparent, dimensionally stable substrate in sheet form; b. a transfer layer, comprising high dielectric constant nanoparticles dispersed in a solvent or a polymer matrix wherein the polymer matrix is selected from polyalcohols, polyamines, polyamides, and polyesters; and c. a heating layer located between the substrate and the transfer layer.


US Patent 7259410 - Nanotube fabric switch

Nantero is a company which has focused on the use of nanotube ribbons to form electromechanical switches in a crossbar configuration. This patent proposes an alternative to the crossbar approach by using nanotube fabric control traces for nanotube fabrics which may be more compatible with semiconductor manufacturing methods. Claim 1 reads:

1. A discrete electro-mechanical device, comprising: a structure including a control structure, the control structure including an electrically-conductive trace; a defined patch of nanotube fabric disposed in spaced relation to the control structure, the nanotube fabric comprising a film of nanotubes; and wherein the defined patch of nanotube fabric is electromechanically deflectable between a first and second state, wherein in the first state the nanotube article is in spaced relation relative to the control structure, and wherein in the second state the nanotube article is in contact with the control structure; and a low resistance signal path in electrical communication with the defined patch of nanofabric.


Tuesday, August 21, 2007

US Patent 7259344 - CNT sorting using light

This patent from Intel focuses on sorting between metallic and semiconducting single walled nanotubes in a fluidic flow path using optical traps created by a laser beam. Such sorting was generally known to the art but this patent provides for multiple chances of selected nanotubes to be captured by the optical trap. Claim 1 reads:

1. A method, comprising sorting carbon nanotubes (CNTs) within a fluidic flow for a targeted subset of said CNTs, said sorting comprising attracting at least a portion of said CNTs within said fluidic flow in a direction of increasing intensity of an electric field component of substantially stationary beam of light, said electric field component having a frequency that is less than one or more resonant frequencies of said CNTs within said portion; and attracting a second portion of said CNTs in a direction of increasing intensity of an electric field component of a substantially stationary second beam of light, said electric field component of said second beam of light having a frequency that is less than one or more resonant frequencies of said CNTs within said second portion, said second portion from those of said CNTs within said fluidic flow that were repelled in a direction of decreasing intensity of said electric field component of said beam of light.

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US Patent 7259101 - Nanoparticle ink from metal monoxide precursors

Nanoparticle based inks are a favored candidate for printing based lithography such as inkjet and nanoimprinting. This patent teaches forming transition metal or semiconductor nanoparticles for purposes. Claim 1 reads:

1. A method of making nanoparticles comprising: a. treating a monoxide precursor to form a composite material comprising nanoparticles and an oxide matrix; b. isolating the nanoparticles from the composite material by treating the oxide matrix to an etchant medium comprises a hydrogen fluoride source.


Thursday, August 16, 2007

US Patent 7256466 - Functionalized semiconductor nanowire

This patent from Harvard includes basic claims to functionalized semiconductor nanowires (including carbon nanotubes). It does have an early priority date (December 11, 2000) and while there is prior art for multiwall carbon nanotube functionalization such as for AFM tips the use of semiconductor nanowires can be more useful for sensing applications. Claim 1 reads:

1. An article comprising: a semiconductor nanowire comprising a core region and an outer region surrounding the core region, wherein the outer region is selectively functionalized with a chemical or biological species added to the nanowire after construction of the nanowire.

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US Patent 7256435 - Multidimensional nanowire crossbar interface

While nanoscale crossbar configurations are one of the leading candidates for future nanoelectronics, current efforts are focused on interconnecting these devices with more conventional electronic devices to enable near term applications. This patent teaches forming connection nanowires on a substrate to have a greater thickness than the other nanowires so that microwires can electrically contact the thick nanowires without interfering with the thin nanowires. Claim 9 reads:

9. An array of approximately parallel nanowires, each nanowire oriented in an X direction having (1) micro dimensions in the X direction, (2) nano dimensions and nano spacing in a Y direction, and at least two distinct heights in a Z direction, the X and Y directions parallel to a surface of a substrate underlying the array of approximately parallel nanowires, and the Z direction normal to the substrate surface, each of said nanowires, selectively making contact with portions of microscopic regions of microscopic wires or pads.

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Wednesday, August 15, 2007

US Patent 7256394 - CNT ion source for mass spectroscopy

This patent from Agilient Technologies teaches the use of uniformly distributed carbon nanotubes in an improved ion source for mass spectroscopy.

9. An ion source for use in ionizing a sample, comprising: (a) a laser; and (b) a surface for holding the sample, the surface comprising a uniformly distributed carbon nanotube material.

Agilient also has a related patent using nanowires (explicitly excluding CNTs)

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US Patent 7255924 - Porous carbon with electroactive polymer coating

Supercapacitors are a new type of electrical storage device which balance the benefits of batteries (high energy density) and capacitors (quick charging/discharging). This patent based on work from the U.S. Naval Research Laboratory (NRL) teaches a new composite for supercapacitors with improved charge/discharge rates by forming an electroactive polymer coating on porous carbon with nanoscale thickness. Claim 1 reads:

1. A composite comprising a porous carbon structure comprising a surface and pores; and a coating on the surface comprising an electroactive polymer; wherein the coating does not completely fill or obstruct a majority of the pores; wherein the coating is formed by self-limiting electropolymerization and does not exceed about 15 nanometers in thickness.

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Tuesday, August 14, 2007

US Patent 7255922 - Skutterudite nanoparticle

Skutterudite is a compound represented by MX.sub.3 (M: Co, Rh, Ir, X: P, As, Sb) and is useful based on it's high thermoelectric performance. This patent from Dai Nippon Printing teaches forming nanoparticles of this material. Claim 1 reads:

1. An inorganic nanoparticle being a skutterudite compound and having an average particle size in a range of 2 nm to 100 nm.


US Patent 7255871 - Biological cell conduit using nanotube mat

This patent from Stanford proposes a new application of nanotubes in growing and organizing biological cells in a vertical direction using nanotube mats. Claim 1 reads:

1. A device to direct growth of biological cells, comprising a nanotube mat wherein said nanotube mat comprises an array of conduits through the thickness of said nanotube mat, wherein said conduits are sized to accommodate said growth of at least one of said biological cells.

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Monday, August 13, 2007

US Patent 7254799 - Nanowire crossbar optimization using graph theory

Nanoscale crossbars are a leading contender for a breakthrough platform for nanoelectronics and has a variety of potential advantages in addition to scaling such as reduced manufacturing cost and the capability of reconfigurability. However there are also some drawbacks including a relatively large percentage of defects. This patent from Hewlett-Packard teaches using graph theory to effectively allocate the working crosspoints. Claim 1 reads:

1. A method for allocating nanowire junctions in a nanowire crossbar, the method comprising: receiving a circuit; receiving a nanowire crossbar having one or more randomly distributed non-functional nanowire junctions; constructing a circuit graph based on the circuit; constructing a crossbar graph based on the nanowire crossbar; searching for a graph monomorphism based on the circuit graph and the crossbar graph; and allocating nanowire junctions of the nanowire crossbar based on the graph monomorphism.

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US Patent 7254151 - Nanowire laser

Forming lasers from semiconductor materials in the form of quantum (i.e. nano) wires has been accomplished several times in the prior art. This patent from Harvard alleges that lasing from nanowires based on "an electric signal from the substrate" is new. Claim 1 reads:

1. An apparatus, comprising: at least one nanoscale wire constructed and arranged to generate amplified stimulated emission of radiation, the at least one nanoscale wire including a first type semiconductor material; and a substrate, wherein the apparatus is constructed and arranged such that at least first carrier types are injected along at least a portion of a length of the at least one nanoscale wire, in response to an electric signal from the substrate, to facilitate generation of the amplified stimulated emission of the radiation.

Unfortunately quantum wire lasing prior art, which does work by electrical stimulation, such as

seems to have been overlooked (see column 5, lines 24-45).

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Friday, August 10, 2007

US Patent 7253941 - Sinusoidal hinge for MEMS

Deflectable mirror devices (DMDs) are micromechanical elements developed by Texas Instruments usefully applied in a variety of areas such as fiber optic switching and projection displays. This patent focuses on a new hinge structure resulting in fewer manufacturing defects. Claim 8 reads:

8. An apparatus comprising: a hinge structure having an approximately sinusoidal profile; and a deflectable member supported by said hinge structure.

While the breadth of the claims may be reasonable if limited to DMDs the Examiner may have overlooked some more traditional hinge structure prior art such as

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US Patent 7253452 - Blue light semiconductor nanocrystal

This patent from M.I.T. teaches fabrication methods for improved light emissive nanocrystals of blue wavelengths. Claim 1 reads:

1. A semiconductor nanocrystal comprising: a core including a first semiconductor material; and an overcoating on the core, the overcoating including a second semiconductor material, wherein the nanocrystal is substantially free of deep-trap emission sites, and the nanocrystal when excited emits blue light.

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Thursday, August 09, 2007

US Patent 7253442 - Uncapped CNT thermal interface

This patent teaches improvements in the use of carbon nanotubes for thermal interfaces by removing the end caps of parallel carbon nanotubes embedded in a matrix. Claim 1 reads:

1. A thermal interface structure comprising: a macromolecular material; and a plurality of carbon nanotubes embedded in the macromolecular material; wherein the thermal interface structure has a first surface and a second surface opposite to the first surface; and each carbon nanotube is open at opposite ends thereof, and extends from the first surface to the second surface.

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US Patent 7253434 - Suspended CNTFET

Carbon nanotube FETs have been proposed in a variety of configurations including structures where the nanotube is used as a vertical structure for gate control and wherein a plurality of nanotubes are aligned over a source/drain connection for gate control. This patent from Harvard proposes a suspended nanotube structure to form the CNTFET. Claim 1 reads:

1. A carbon nanotube field effect transistor comprising: a carbon nanotube having a length suspended between a source electrode and a drain electrode that are together disposed on a common surface of a support structure; a gate dielectric material coaxially coating the suspended nanotube length and coating at least a portion of the source and drain electrodes; and a gate metal layer coaxially coating the gate dielectric material along the suspended nanotube length and overlapping a portion of the source and drain electrodes, separated from the electrodes by the gate dielectric material.


Wednesday, August 08, 2007

US Patent 7253431 - Carbon nanotube doping using one electron oxidant

Depending on their chirality single walled nanotubes have intrinsic semiconductor properties however extrinsic doping using O2, NO2, Br2, and I2 (electron acceptors) and K, Cs, NH3 (electron donors) have also been reported in the literature. This patent from IBM teaches using what they refer to as "one-electron oxidants" which is taught in the specification to include itrialkyloxonium hexachlroantimonate, antimony pentachloride, nitrosonium salts, tris-(pentafluorophenyl) borane or nitrosonium cation to provide more reliable preparation of extrinsically doped nanotubes for FETs. Claim 1 reads:

1. A method for doping a carbon nanotube comprising: exposing the carbon nanotube to a one-electron oxidant in a solution, such that one electron is transferred from the carbon nanotube to each molecule of the one-electron oxidant.

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US Patent 7253119 - Nanoparticle etching/passivating process

This patent from Rensselaer Polytechnic Institute teaches a fairly interesting way of manufacturing nanoparticles in solution which combines etching to reduce the size of the nanoparticles and passivation to avoid agglomeration. Claim 1 reads:

1. A method of making semiconductor nanoparticles, comprising: forming semiconductor nanoparticles of a first size in an aqueous solution; and providing an etching liquid into the solution to etch the semiconductor nanoparticles of the first size to a second size smaller than the first size; wherein the solution contains a passivating element which binds to dangling bonds on a surface of the nanoparticles to passivate the surface of the nanoparticles.


Tuesday, August 07, 2007

US Patent 7252928 - Reducing microchannel adsorption using colloidal material flow

When using microfluidic devices to analyze biological materials such as proteins a problem can occur of the material being adsorbed in the microchannel walls. This patent from Caliper Life Sciences teaches adding a colloidal material flow which binds to the biological material reducing the adherence to the channel walls. Claim 1 reads:

1. A method of reducing adsorption of one or more materials to an interior surface of a microchannel, the method comprising flowing the one or more macromolecules in a fluid in the microchannel, and concomitantly flowing a colloidal material through the fluid in the microchannel at a sufficient concentration to bind to the one or more materials and thereby prevent the materials from binding to the interior surface of the microchannel.


US Patent 7252884 - Porous carbon with carbon nanotube dispersion

This patent from NASA deals with an improved hydrogen storage material with more uniform porosity and improved strength by dispersing carbon nanotubes into a porous carbon matrix. Claim 1 reads:

1. A three-dimensional structure comprising solid carbon having carbon nanotubes (CNTs) dispersed therein, said solid carbon with said CNTs dispersed therein being formed about three-dimensionally ordered spherical voids arranged in an opal-like lattice, said solid carbon being generated by carbonization of a carbon yield material having said CNTs dispersed therein.

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US Patent 7252265 - Flying cellphone

This patent involves an invention which seems somewhat foolish at first glance but when you consider the number of increasing functions as well as size reduction of cellphones I guess it is to be expected. Basically a propulsion device is attached to a cell phone to create a hovering device capable of remote observation (via the cellphone's camera). Claim 1 reads:

1. An aircraft in combination with a cellular phone, the aircraft comprising: a body having at least four ring-shaped co-planar rotors; a plurality of motors, each motor operative to control a respective one of said rotors; and an electronic controller operative to control said plurality of motors, wherein, the aircraft is attachable to at least a portion of the cellular phone in a removable manner, and wherein the aircraft is smaller in size than the cellular phone, such that when the aircraft is attached to the cellular phone, the aircraft forms a removable wall portion of the cellular phone.

Thursday, August 02, 2007

US Patent 7250386 - Non-crystalline quantum limit catalyst

The inventor of this patent (Stanford Ovshinsky) is arguably the world leading authority on amorphous (non-crystalline) semiconductor materials and has been patenting in this area for several decades. This particular patent is directed to a new amorphous quantum material adapted for hydrogen storage. Claim 1 reads:

1. A quantum limit catalyst comprising: catalytic atomic aggregations, said atomic aggregations consisting essentially of an assembly of atoms of one or more metal elements, said atomic aggregations having a size of 100 angstroms or less, said size placing said atomic aggregations in the quantum limit, said quantum limit atomic aggregations having a non-crystalline structure.

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Wednesday, August 01, 2007

US Patent 7250366 - Fabrication of metallized CNT bundle

This patent from Intel teaches the fabrication of metallized carbon nanotube bundles of regulated length and diameter useful to form conductors. Claims 1 and 16 are representative:

1. A method comprising: forming an opening in a layer on a conductive layer of a substrate; forming a catalyst in the opening; fabricating a carbon nanotube bundle on the catalyst; removing material from the carbon nanotube bundle; and forming a metallization on the carbon nanotube bundle to form a metallized carbon nanotube bundle including the metallization and the catalyst.

16. A method comprising: flowing a solution including a metallized carbon nanotube bundle on a substrate including a trench to place the metallized carbon nanotube bundle into the trench; and forming a connection between the metallized carbon nanotube bundle and a via plug in the trench.

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US Patent 7250147 - Diazonium derivatized carbon nanotubes

The inventors of this patent are fairly well known names in molecular electronics (including James Tour) and include a fairly broad claim to using diazonium in derivitization. One indication that this could be an important patent is that wikipedia has a page discussing diazonium derivitized carbon nanotubes-
Claim 1 reads:

1. A method comprising: (a) selecting a plurality of carbon nanotubes; and (b) reacting the plurality of carbon nanotubes with a diazonium specie to form derivatized carbon nanotubes, wherein the diazonium specie is formed in situ.

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