Friday, December 31, 2010

US Patent 7859104 - CNT thermal interface with transition structure

In order to continue the transistor scaling rates predicted by Moore's Law there is an increased interest in fabricating 3D circuit architectures by stacking multiple semiconductor layers. Due to the increased density of these designs more efficient cooling solutions will need to be developed to deal with the increased heat generation. This patent from Hon Hai Precision teaches one such solution using the high thermal transport properties of carbon nanotubes. Claim 1 reads:

1. A thermal interface material comprising:

a carbon nanotube array comprising a plurality of carbon nanotubes, spaces being defined between adjacent carbon nanotubes;

a transition structure covering an entire peripheral surface of each of the carbon nanotubes; and

a matrix occupying the spaces and encompassing the carbon nanotubes with each transition structure disposed between the matrix and a corresponding one of the carbon nanotubes;

wherein each of the carbon nanotubes has a length substantially equal to a thickness of the matrix, and each transition structure has a length substantially equal to the thickness of the matrix.


US Patent 7859036 - Memristive memory with conical nanowire electrode

This patent from Micron Technology teaches another variation of memristive memory using conically shaped nanowires to reduce the energy required to write and erase memory states. Claim 1 reads:

1. A memory device comprising at least one memory cell having

an anode,

a cathode, and

a volume of variable resistance material disposed between the anode and the cathode,

at least one of the anode and the cathode comprising a single nanowire having one end thereof in electrical contact with the variable resistance material,

wherein the at least one of the anode and the cathode comprising the single nanowire further comprises a generally conical-shaped conductive catalytic structure comprising a catalyst material with the single nanowire formed on a tip thereof.


US Patent 7859035 - Fullerene MIM memory

Certain metal-insulator-metal structures have shown to exhibit memristive (i.e. memory resistive) effects which have been suggested as a new form of non-volatile memory called ReRAM and which has been projected to be a future replacement for Flash memory. This patent from Samsung teaches one variation or ReRAM using fullerene material. Claim 1 reads:

1. A storage node, comprising:

a first metal layer;

a first insulating layer;

a second metal layer; and

a first nano-structure layer, sequentially stacked,

the first nano-structure layer being formed on an upper surface of the second metal layer, wherein the first metal layer is a lower electrode, the second metal layer is an upper electrode, and the first nano-structure layer is a carbon nano-structure layer.


Thursday, December 30, 2010

US Patent 7858990 - Trench graphene FET

Graphene has attracted attention due to its high electron mobility (about 100x silicon) and since its band gap can be tuned based on the control of fabricated dimensions. This patent from AMD proposes a fabrication method to simplify manufacture of graphene based electronics. Claim 1 reads:

1. A process comprising:

forming a trench defined by one or more layers of material;

forming a graphene layer within the trench; and

forming a device structure on the graphene layer and within the trench.


US Patent 7858968 - Organic CNTFET

This patent from Panasonic teaches a thin film organic transistor using nanotubes in the channel for applications such as flexible LCDs. Claim 1 reads:

1. A field effect transistor comprising:

a semiconductor layer through which carriers injected from a source region travel toward a drain region,

the semiconductor layer being formed from a composite material comprising an organic semiconductor material and nanotubes,

wherein plural ones of the nanotubes are chemically joined with each other in the semiconductor layer.


US Patent 7858965 - Ge/Si nanowires

One problem with semiconductor nanowires in electronics is the formation of Schottky barriers which inhibit conduction at the interface between metal contacts and the nanowires. This patent is based on research from Charles Lieber's group at Harvard and teaches using nanowire heterostructure with a germanium core and silicon shell to help eliminate Schottky barriers. Claim 1 reads:

1. An electronic device, comprising:

a nanoscale wire consisting essentially of a core consisting essentially of undoped germanium and a shell surrounding the core consisting essentially of undoped silicon, the shell in physical contact with a first contact consisting essentially of nickel metal and a second contact,

wherein the shell of the nanoscale wire and the nickel metal contact form a Schottky barrier of less than 0.5 eV, and

wherein the nanoscale wire exhibits ballistic transport when subjected to a voltage via the first and second contacts.


US Patent 7858876 - Graphene photovoltaics

Graphene has been popularized in the last few years as a way to achieve higher speed electronics in the 21st century. This patent also teaches usefulness of graphene toward the production of solar cells. Claim 1 reads:

1. A photovoltaic cell comprising:

(a) a first contact comprising a first electrically conductive contact material;

(b) a second contact comprising a second electrically conductive material; and

(c) a plurality of spatially separated graphite stacks bridging the first and second contacts, each graphite stack comprising a plurality of vertically stacked, semiconducting graphene sheets;

wherein junctions between the first electrically conductive material and the graphene sheets form Schottky barriers for electrons or holes.

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US Patent 7858186 - Fluorinated nanodiamond

Chemical vapor deposition (CVD) has commonly been used to form diamond thin films and coatings but requires high temperature and cost. This patent from Rice University teaches an alternative technique using nanodiamonds to form coated surfaces. Claim 1 reads:

1. A nanodiamond coated surface comprising:

a) a substrate surface; and

b) fluorinated nanodiamond crystallites,

wherein the fluorinated nanodiamond crystallites are covalently bound to the substrate surface via a silane linker species; and

wherein the silane linker species further comprises an amine that is covalently bound to the fluorinated nanodiamond crystallites.


US Patent 7858185 - High purity nanotube fabric

This latest patent from Nantero includes basic claims to purified carbon nanotube films capable of being integrated into CMOS semiconductor processes. Claim 1 reads:

1. A nanotube film comprising:

a solution-deposited network of connected and purified nanotubes on a substrate,

wherein the nanotubes form a film of substantially uniform porosity, the film is free of amorphous carbon, the film is free of polymer and surfactants, the film comprises less than about 1×1018 atoms/cm2 of metallic impurities, and the film is free of particle impurities having a diameter of greater than about 500 nm.


Tuesday, December 28, 2010

US Patent 7858181 - Si nanowires grown from Au nanocrystals

Much of the early work and basic patents in fabricating nanowires over the past decade has been credited to Charles Lieber's group at Harvard but this patent from Brian Korgel of the University of Texas at Austin includes some claims which may be equally fundamental with a priority date of July 8, 2003. Claim 1 reads:

1. Crystalline nanowires comprising a group IV metal, which are substantially straight and substantially free of group IV metal nanoparticles; wherein each of the nanowires further comprises a non-group IV metallic nanocrystal at one end of the nanowire.

US Patent 7857993 - Nanocomposite scintillator

Scintillators are materials that emit light upon absorbing ionized particles and are a primary component for radiation detectors. However, neutron detection can be difficult with scintillators due to their lack of ionization. This patent from UT-Battelle teaches using fluorescent nanocrystals (quantum dots) to improve the reliability and emission intensity of scintillators. Claim 1 reads: 

1. A composite scintillator comprising a non-fluorescent transparent matrix containing therein microscale spheres encapsulating fluorescent nano-sized objects and a neutron target material.


US Patent 7857956 - Nanotube controlled dielectrophoresis

Dielectrophoresis is a method commonly used in microfluidics which uses AC electric fields to manipulate biomaterials. This patent from the Regents of the University of California takes this to the nanoscale by using carbon nanotubes as the electrodes generating the AC fields. Claim 1 reads:

1. A method of dielectrophoretically manipulating a polarizable object with elongated nanoelectrodes, comprising:

positioning a polarizable object in proximity with a first and a second elongated nanoelectrode, wherein said first elongated nanoelectrode is cylindrically shaped and comprises at least one nanotube; and

applying a time-varying electric field between the first and second nanoelectrodes, the field being sufficient to manipulate the polarizable object.


Wednesday, December 22, 2010

US Patent 7855496 - Boron nitride nanotube paste

Carbon nanotubes have been shown to exhibit superior electron emission properties but may have a short lifespan if they are in an oxygen environment. This patent from Samsung teaches an alternative electron emitting nanomaterials based on a boron nitride nanotube paste. Claim 1 reads:

1. A boron nitride nanotube paste composition comprising:

about 100 parts by weight boron nitride nanotubes;

from about 500 to about 2000 parts by weight glass frit;

from about 1000 to about 2000 parts by weight filler;

from about 2000 to about 4000 parts by weight organic solvent; and

from about 4000 to about 6000 parts by weight polymer binder.


US Patent 7854997 - Cobalt-nickel nanoparticles for adhesive

This patent from Boeing takes advantage of the high surface area of nanoparticle materials to improve the effectiveness of adhesives used in metal bonding. Claim 1 reads:

1. A metallic substrate comprising a precipitate-coated surface, the precipitate-coated surface comprising:

a precipitate, the precipitate comprising nanoparticulates, a first portion of the nanoparticulates adheres to a surface of the metallic substrate and a second portion of the nanoparticulates is in contact with the first portion of nanoparticulates;

wherein the metallic substrate comprises aluminum or an aluminum alloy; and

wherein the precipitate comprises clusters of cobalt-nickel nanoparticulates, the cobalt-nickel nano particulates in a size range from about 50 nm to about 1000 nm.


US Patent 7854991 - Aligned SWCNT array with high purity and surface area

This patent from National Institute of Advanced Industrial Science and Technology teaches CVD growth methods for single walled carbon arrays resulting in high purity and surface area. Claim 1 reads:

1. A single-walled carbon nanotube bulk structure comprising a plurality of aligned single-walled carbon nanotubes,

wherein a specific surface area of the plurality of aligned single-walled carbon nanotubes is 800 m2/g or more and 2,500 m2/g or less, and

purity measured by fluorescence X-rays of the plurality of aligned single-walled carbon nanotubes is 98% or more.


US Patent 7854826 - CNT transistor biosensor

This patent from Korea Research Institute of Chemical Technology teaches a carbon nanotube transistor biosensor capable of recognizing a specific protein by using DNA aptamers. Claim 1 reads:

1. A carbon nanotube transistor biosensor using a single stranded DNA or single stranded RNA aptamer, comprising:

(a) a carbon nanotube transistor comprising a source, a drain, and a gate, and a channel domain which consists of a carbon nanotube;

(b) a single stranded DNA or single stranded RNA aptamer immobilized on the surface of said carbon nanotube for molecular recognition, and

(c) a linker material to immobilize aptamers on the surface of a carbon nanotube;

wherein said carbon nanotube transistor biosensor contains an electrical double layer.


Monday, December 20, 2010

US Patent 7851841 - Core/shell nanowire transistor

This latest patent from Nanosys has relatively early priority (Sep. 30, 2002) and includes some basic claims to field effect transistors formed from core-shell nanowires. Claim 1 reads:

1. A semiconductor device comprising:

a substrate;

a plurality of nanowires deposited or formed on the substrate, wherein said nanowires each comprise a core made of a first material and at least a first shell layer made of a second material disposed about said core, wherein said second material is made from a high dielectric constant material; and

at least a first source contact and a first drain contact formed in or on the substrate providing electrical connectivity to the plurality of nanowires, wherein the nanowires each form an individual channel between said at least first source and drain contacts.


US Patent 7851790 - Isolated germanium nanowire on silicon fin

Germanium was the first material used for transistors but was quickly replaced with silicon which was found to produce better thermal stability and provide manufacturing advantages. As higher speed electronics are desired germanium may again become an option due to its higher mobility. This patent from Intel teaches a germanium nanowire as a channel of FinFET type transistors. Claim 1 reads:

1. A Germanium nanowire of comprising:

a Germanium core; and

a Silicon Oxide shell disposed around said Gemanium core;

wherein the Germanium nanowire comprises a diameter of 30-45 nm.


US Patent 7851292 - CNT floating gate memory

This patent from Micron Technologies teaches a way to form floating gate memory cells used in Flash memory with carbon nanotubes in the transistor channels to facilitate ballistic electron injection. Claim 1 reads:

1. A method of forming a floating-gate memory cell, comprising:

forming source/drain regions in a semiconductor substrate, wherein the source/drain regions define a channel region therebetween;

forming a plurality of carbon nanotubes overlying at least a portion of the channel region;

forming a tunnel dielectric layer overlying the carbon nanotubes;

forming a floating-gate layer overlying the tunnel dielectric layer;

forming an intergate dielectric layer overlying the floating-gate layer; and

forming a control gate layer overlying the intergate dielectric layer.


US Patent 7850943 - White light nanocrystals

This patent from Samsung teaches forms of semiconductor nanocrystals such as InZnP which emit at multiple wavelengths which can be useful to create white light LEDs. Claim 1 reads:

1. A semiconductor nanocrystal, which is devoid of a cadmium sulfide nanocrystal, wherein semiconductor nanocrystal shows luminescence peaks at two or more wavelengths.


US Patent 7850940 - Carbonnitride nanotubes

This patent from Korea Advance Institute of Science and Technology teaches a method for controllably manufacturing a form of nanotube based on carbon and nitrogen useful to sensors, batteries, and displays. Claim 1 reads:

1. A method for controlling the size and quantity of pores in C1-xNx nanotube by reacting hydrocarbon gas, nitrogen gas and oxygen gas together in the presence of metal catalyst, wherein x ranges from 0.001 to 0.2, and wherein the size and quantity of pores are controlled by controlling the concentration of nitrogen gas.


US Patent 7850798 - Flash welding of conducting polymer nanofibers

Due to their high surface area nanostructured materials often have heightened sensitivity to radiation and light. This patent from the Regents of the University of California takes advantage of this property by exposing the nanofibers to a light flash which melts individual nanowires and integrates the nanowires into a continuous film. Claim 1 reads:

1. A process for welding together nanofibers consisting of one or more thermosetting conjugated electrically conductive polymers, the nanofibers collected as a random mat, comprising

exposing the random mat of said nanofibers of said one or more thermosetting polymers to a burst of a high intensity flash of light.


Wednesday, December 08, 2010

US Patent 7849424 - Computer aided design of nanowire transparent film

This patent from Cambrios Technologies Corporation teaches CAD techniques used to optimize the electrical conductivity and transparency of nanowire thin films. Claim 1 reads:

1. A method for controlling a process of fabricating a transparent conductor film having nanowires, the method comprising:

receiving, by a processor, an input specification of a physical characteristic of the transparent conductor film;

comparing, by the processor, the input specification to stored reference data correlating a physical characteristic of reference transparent conductor films to a physical characteristic of reference nanowires;

generating a manufacturing specification that correlates a target physical characteristic of the nanowires to the input specification; and

controlling a physical characteristic of the nanowires of the transparent conductor film based on the manufacturing specification.


US Patent 7847588 - Self-adjusting nanotube FPGA

Nantero has been working on programmable logic structures made from carbon nanotube switches for several years. This latest patent teaches an adaptive nanotube logic which adjusts for time delays between remote areas of circuitry. Claim 1 reads:

1. A self-adjusting nanotube field programmable system comprising:

a processing system and at least one subsystem interconnected to the processing system by at least one control line and at least one data line;

a logic circuit comprising a first plurality of nanotube field programmable devices, wherein the logic circuit controls timing of a first electrical signal transmitted on the at least one control line from the processing system to the at least one subsystem;

wherein the logic circuit compensates for delays of the first electrical signal, the delays being a function of at least the propagation distance between the processing system and the at least one subsystem and the response time delay between the processing system and the at least one subsystem;
wherein the processing system compares a second electrical signal generated by the processing system to a third electrical signal generated by the at least one subsystem and transmitted on the at least one data line to the processing system by the at least one subsystem;

wherein when the second and third electrical signals do not match, the logic circuit adjusts the propagation delay between the processing system and the at least one subsystem.


US Patent 7847325 - Discrete trap memory mediated by fullerenes

There have been a variety of proposals over the past several years for using nanocrystals in the trap oxide of floating gate memory cells to enhance the scalability and reliability of Flash memory. This patent from Infineon Technology teaches a variation of this concept which instead uses fullerenes such as C60 to control the density and distribution of charge traps. Claim 1 reads:

1. A method for manufacturing a memory device, comprising:

arranging a plurality of Fullerenes on an oxide layer to form a mask, wherein the oxide layer is exposed through the mask at gaps between the plurality of Fullerenes;

depositing nano-crystals over the mask; and

trapping the nano-crystals in gaps between the plurality of Fullerenes.


Tuesday, December 07, 2010

US Patent 7847285 - Configurable power segmentation using nanotubes

This patent from LSI Corporation teaches smart power management of microprocessors using carbon nanotube switches. Claim 1 reads:

1. A microelectronic assembly, comprising:

a transistor layer of an integrated circuit above a semiconductor substrate, the transistor layer including a plurality of transistors;

a power source to supply power to the plurality of transistors; and

a nanotube structure patterned adjacent to the transistor layer, the nanotube structure to be bent to a conductive surface when a current is applied to the nanotube structure, the bent nanotube structure to couple the power source to the plurality of transistors to provide a power to the plurality of transistors, and be bent away from the conductive surface when the current is removed from the nanotube structure, the bent away nanotube structure to decouple the power source from the plurality of transistors to remove the power from the plurality of transistors, the nanotube structure to be bent away from the conductive surface based on a power utilization rate of the plurality of transistors meeting a threshold level.


US Patent 7847273 - CNT electron gun with alignment mechanism

Electron guns typically require a positively charged electrode to facilitate electron extraction but any misalignment between the electron source and extractor can cause focusing problems. This patent from ELORET Corporation teaches a carbon nanotube electron emitter which includes alignment features. Claim 1 reads:

1. An electron source comprising:

a substrate;

a conductive material disposed on said substrate;

a carbon nanotube coupled to said conductive material; and

wherein said substrate comprises a first feature operable to interface with an extractor of an electron gun, and wherein said first feature is further operable to position said carbon nanotube with respect to said extractor.


US Patent 7846807 - Manufacture of mem-resistor material

In 2008 researchers at HPLabs published a few papers linking resistance switching properties of nanometer thin film TiO2 to the concept of a mem-resistor (i.e. memory resistor). The mechanism of resistance switching was proposed to be based on oxygen vacancies but no new manufacturing methods specific to memory resistors were disclosed. This patent from Hermes-Epitek Corp of Taiwan teaches a way to form such vacancies to generate mem-resistor thin films. Claim 1 reads:

1. A method for forming a memristor material by using ion implantation, comprising:

providing a substrate having a MA layer formed thereon, wherein A is an electron-rich element and M is an element selected from a group consisting of transition metal and non-metal;

implanting a plurality of B components into said MA layer; and

treating said MA layer, such that at least a portion of AB components formed by a chemical reaction between said A and said B are expelled away from said MA layer and then a plurality of A vacancies are distributed inside said MA layer.


Monday, December 06, 2010

US Patent 7844347 - CNT-polymer medical electrodes

Contacts between electrodes and biological tissue often include an unwanted impedance which make measurement or stimulation difficult. This patent from Medtronic teaches using an electrically conductive CNT polymer to reduce the contact resistance. Claim 1 reads:

1. In a medical device, comprising:

a lead body;

an elongated conductor extending through the lead body;

at least one electrode electrically coupled to the elongated conductor;

an electrically conductive adhesive layer on at least a portion of the at least one electrode; and

a polymer combined with a plurality of carbon nanotubes to render the polymer conductive and electrically coupled to the electrically conductive adhesive layer, the polymer comprising one of polyurethane and silicone, wherein the plurality of carbon nanotubes comprise open ends arranged for contact with biological tissue when the at least one electrode is implanted in the body.


US Patent 7842535 - Silicon nanopillar lithium battery

This patent to Nexeon Ltd. appears to be fundamental to nanostructured silicon anodes used in lithium batteries. Claim 1 reads:

1. A method of fabricating an energy storage device comprising the steps of:

forming an anode comprising an array of sub-micron silicon structures supported on a silicon substrate;

forming a cathode comprising lithium; and

arranging the anode and cathode in communication to form a battery.


US Patent 7842522 - CNT field emitter well

Carbon nanotube inks and pastes have been used to form electron emission structures for flat panel displays but it can be difficult to achieve uniformity of the nanotube distribution when depositing the ink. This patent from Applied Nanotech teaches a process to facilitate uniformity using well formations. Claim 1 reads:

1. A process of depositing a carbon nanotube (CNT) composition in wells formed in a cathode structure whereby a post-deposition process is not performed on the cathode structure subsequent to deposition of the CNT ink-like composition, wherein the post-deposition process removes material from the cathode structure.


Sunday, December 05, 2010

US Patent 7842432 - Nanowire diffusion control barrier for fuel cells

This patent from Nanosys teaches a fuel cell membrane formed from a mixture of semiconductor nanowires and graphene. Claim 2 reads:

2. A fuel cell comprising

a fuel source,

a proton exchange membrane,

an anode electrode,

a cathode electrode and

a diffusion-controlling barrier comprising an interconnected network of nanowires, wherein fuel concentration at the proton exchange membrane is less than about 30% of that of the fuel source.


US Patent 7842385 - Coated nanoparticle illuminator

This patent from Samsung teaches selecting the refractive index of the coating of quantum dot nanoparticles in order to enhance the luminous efficiency of qdot LEDs and displays. Claim 1 reads:

1. A matrix dispersed coated nanoparticle, comprising:

a nanoparticle, which receives and emits light;

a coating material formed on a surface of the nanoparticle, the coating material having an index of refraction which is less than an index of refraction of the nanoparticle; and

a matrix disposed on the coating material, wherein the index of refraction of the coating material is greater than an index of refraction of the matrix.