Patents by Inventor Xiangfeng Duan

Xiangfeng Duan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20090065764
    Abstract: Methods for forming or patterning nanostructure arrays are provided. The methods involve formation of arrays on coatings comprising nanostructure association groups, patterning using resist, and/or use of devices that facilitate array formation. Related devices for forming nanostructure arrays are also provided, as are devices including nanostructure arrays (e.g., memory devices).
    Type: Application
    Filed: November 5, 2008
    Publication date: March 12, 2009
    Applicant: NANOSYS, Inc.
    Inventors: David L. Heald, Karen Chu Cruden, Xiangfeng Duan, Chao Liu, J. Wallace Parce
  • Patent number: 7501315
    Abstract: Methods for forming or patterning nanostructure arrays are provided. The methods involve formation of arrays on coatings comprising nanostructure association groups, patterning using resist, and/or use of devices that facilitate array formation. Related devices for forming nanostructure arrays are also provided, as are devices including nanostructure arrays (e.g., memory devices).
    Type: Grant
    Filed: June 7, 2005
    Date of Patent: March 10, 2009
    Assignee: Nanosys, Inc.
    Inventors: David L. Heald, Karen Chu Cruden, Xiangfeng Duan, Chao Liu, J. Wallace Parce
  • Publication number: 20090057650
    Abstract: The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components.
    Type: Application
    Filed: February 27, 2008
    Publication date: March 5, 2009
    Applicant: President and Fellows of Harvard College
    Inventors: Charles M. Lieber, Xiangfeng Duan, Yi Cui, Yu Huang, Mark Gudiksen, Lincoln J. Lauhon, Jianfang Wang, Hongkun Park, Qingqiao Wei, Wenjie Liang, David C. Smith, Deli Wang, Zhaohui Zhong
  • Patent number: 7476596
    Abstract: A bulk-doped semiconductor that is at least one of the following: a single crystal, an elongated and bulk-doped semiconductor that, at any point along its longitudinal axis, has a largest cross-sectional dimension less than 500 nanometers, and a free-standing and bulk-doped semiconductor with at least one portion having a smallest width of less than 500 nanometers. At least one portion of such a semiconductor may a smallest width of less than 200 nanometers, or less than 150 nanometers, or less than 100 nanometers, or less than 80 nanometers, or less than 70 nanometers, or less than 60 nanometers, or less than 40 nanometers, or less than 20 nanometers, or less than 10 nanometers, or even less than 5 nanometers. Such a semiconductor may be doped during growth. Such a semiconductor may be part of a device, which may include any of a variety of devices and combinations thereof, and a variety of assembling techniques may be used to fabricate devices from such a semiconductor.
    Type: Grant
    Filed: October 4, 2006
    Date of Patent: January 13, 2009
    Assignee: President and Fellows of Harvard College
    Inventors: Charles M. Lieber, Yi Cui, Xiangfeng Duan, Yu Huang
  • Publication number: 20080290394
    Abstract: A nonvolatile memory cell includes a substrate comprising a source, drain, and channel between the source and the drain. A tunnel dielectric layer overlies the channel, and a localized charge storage layer is disposed between the tunnel dielectric layer and a control dielectric layer. A gate electrode has a first surface adjacent to the control dielectric layer, and the first surface includes a midsection and two edge portions. According to one embodiment, the midsection defines a plane, and at least one edge portion extends away from the plane. Preferably, the edge portion extending away from the plane converges toward an opposing second surface of the gate electrode. According to another embodiment, the gate electrode of the nonvolatile memory cell includes a first sublayer and a second sublayer of a different width on the first sublayer.
    Type: Application
    Filed: May 15, 2008
    Publication date: November 27, 2008
    Inventors: Xiangfeng DUAN, Jian Chen, J. Wallace Parce, Francisco A. Leon
  • Publication number: 20080293244
    Abstract: Methods of positioning and orienting nanostructures, and particularly nanowires, on surfaces for subsequent use or integration. The methods utilize mask based processes alone or in combination with flow based alignment of the nanostructures to provide oriented and positioned nanostructures on surfaces. Also provided are populations of positioned and/or oriented nanostructures, devices that include populations of positioned and/or oriented nanostructures, systems for positioning and/or orienting nanostructures, and related devices, systems and methods.
    Type: Application
    Filed: August 5, 2008
    Publication date: November 27, 2008
    Applicant: NANOSYS, INC.
    Inventors: Xiangfeng Duan, Hugh Daniels, Chunming Niu, Vijendra Sahi, James Hamilton, Linda T. Romano
  • Patent number: 7427328
    Abstract: A method and apparatus for an electronic substrate having a plurality of semiconductor devices is described. A thin film of nanowires is formed on a substrate. The thin film of nanowires is formed to have a sufficient density of nanowires to achieve an operational current level. A plurality of semiconductor regions are defined in the thin film of nanowires. Contacts are formed at the semiconductor device regions to thereby provide electrical connectivity to the plurality of semiconductor devices. Furthermore, various materials for fabricating nanowires, thin films including p-doped nanowires and n-doped nanowires, nanowire heterostructures, light emitting nanowire heterostructures, flow masks for positioning nanowires on substrates, nanowire spraying techniques for depositing nanowires, techniques for reducing or eliminating phonon scattering of electrons in nanowires, and techniques for reducing surface states in nanowires are described.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: September 23, 2008
    Assignee: Nanosys, Inc.
    Inventors: Xiangfeng Duan, Chunming Niu, Stephen A. Empedocles, Linda T. Romano, Jian Chen, Vijendra Sahi, Lawrence A. Bock, David P. Stumbo, J. Wallace Parce, Jay L. Goldman
  • Publication number: 20080224123
    Abstract: The present invention provides methods and systems for nanowire alignment and deposition. Energizing (e.g., an alternating current electric field) is used to align and associate nanowires with electrodes. By modulating the energizing, the nanowires are coupled to the electrodes such that they remain in place during subsequent wash and drying steps. The invention also provides methods for transferring nanowires from one substrate to another in order to prepare various device substrates. The present invention also provides methods for monitoring and controlling the number of nanowires deposited at a particular electrode pair, as well as methods for manipulating nanowires in solution.
    Type: Application
    Filed: November 9, 2007
    Publication date: September 18, 2008
    Inventors: Samuel Martin, Xiangfeng Duan, Katsumasa Fujii, James M. Hamilton, Hiroshi Iwata, Francisco Leon, Jeffrey Miller, Tetsu Negishi, Hiroshi Ohki, J. Wallace Parce, Cheri X.Y. Pereira, Paul John Schuele, Akihide Shibata, David P. Stumbo, Yasunobu Okada
  • Patent number: 7422980
    Abstract: Methods of positioning and orienting nanostructures, and particularly nanowires, on surfaces for subsequent use or integration. The methods utilize mask based processes alone or in combination with flow based alignment of the nanostructures to provide oriented and positioned nanostructures on surfaces. Also provided are populations of positioned and/or oriented nanostructures, devices that include populations of positioned and/or oriented nanostructures, systems for positioning and/or orienting nanostructures, and related devices, systems and methods.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: September 9, 2008
    Assignee: Nanosys, Inc.
    Inventors: Xiangfeng Duan, R. Hugh Daniels, Chunming Niu, Vijendra Sahi, James M. Hamilton, Linda T. Romano
  • Publication number: 20080200028
    Abstract: Methods of positioning and orienting nanostructures, and particularly nanowires, on surfaces for subsequent use or integration. The methods utilize mask based processes alone or in combination with flow based alignment of the nanostructures to provide oriented and positioned nanostructures on surfaces. Also provided are populations of positioned and/or oriented nanostructures, devices that include populations of positioned and/or oriented nanostructures, systems for positioning and/or orienting nanostructures, and related devices, systems and methods.
    Type: Application
    Filed: November 21, 2006
    Publication date: August 21, 2008
    Applicant: Nanosys, Inc.
    Inventors: Xiangfeng Duan, Hugh Daniels, Chunming Niu, Vijendra Sahi, James Hamilton, Linda T. Romano
  • Publication number: 20080150003
    Abstract: Methods and apparatuses for electronic devices such as non-volatile memory devices are described. The memory devices include a multi-layer control dielectric, such as a double or triple layer. The multi-layer control dielectric includes a combination of high-k dielectric materials such as aluminum oxide (Al2O3), hafnium oxide (HfO2), and/or hybrid films of hafnium aluminum oxide. The multi-layer control dielectric provides enhanced characteristics, including increased charge retention, enhanced memory program/erase window, improved reliability and stability, with feasibility for single or multistate (e.g., two, three or four bit) operation.
    Type: Application
    Filed: December 20, 2006
    Publication date: June 26, 2008
    Inventors: Jian Chen, Xiangfeng Duan, Karen Cruden, Chao Liu, Madhuri L. Nallabolu, Srikanth Ranganathan, Francisco Leon, J. Wallace Parce
  • Publication number: 20080150004
    Abstract: Methods and apparatuses for electronic devices such as non-volatile memory devices are described. The memory devices include a multi-layer control dielectric, such as a double or triple layer. The multi-layer control dielectric includes a combination of high-k dielectric materials such as aluminum oxide (Al2O3), hafnium oxide (HfO2), and/or hybrid films of hafnium aluminum oxide. The multi-layer control dielectric provides enhanced characteristics, including increased charge retention, enhanced memory program/erase window, improved reliability and stability, with feasibility for single or multistate (e.g., two, three or four bit) operation.
    Type: Application
    Filed: March 19, 2007
    Publication date: June 26, 2008
    Applicant: NANOSYS, INC.
    Inventors: Jian Chen, Xiangfeng Duan, Karen Cruden, Chao Liu, Madhuri L. Nallabolu, Srikanth Ranganathan, Francisco Leon, J. Wallace Parce
  • Patent number: 7382017
    Abstract: Methods and apparatuses for nanoenabled memory devices and anisotropic charge carrying arrays are described. In an aspect, a memory device includes a substrate, a source region of the substrate, and a drain region of the substrate. A population of nanoelements is deposited on the substrate above a channel region, the population of nanolements in one embodiment including metal quantum dots. A tunnel dielectric layer is formed on the substrate overlying the channel region, and a metal migration barrier layer is deposited over the dielectric layer. A gate contact is formed over the thin film of nanoelements. The nanoelements allow for reduced lateral charge transfer. The memory device may be a single or multistate memory device.
    Type: Grant
    Filed: April 3, 2007
    Date of Patent: June 3, 2008
    Assignee: Nanosys, Inc
    Inventors: Xiangfeng Duan, Calvin Y. H. Cho, David L. Heald, Chunming Niu, J. Wallace Parce, David P. Stumbo
  • Patent number: 7339184
    Abstract: The present invention is directed to methods to harvest, integrate and exploit nanomaterials, and particularly elongated nanowire materials. The invention provides methods for harvesting nanowires that include selectively etching a sacrificial layer placed on a nanowire growth substrate to remove nanowires. The invention also provides methods for integrating nanowires into electronic devices that include placing an outer surface of a cylinder in contact with a fluid suspension of nanowires and rolling the nanowire coated cylinder to deposit nanowires onto a surface. Methods are also provided to deposit nanowires using an ink-jet printer or an aperture to align nanowires. Additional aspects of the invention provide methods for preventing gate shorts in nanowire based transistors. Additional methods for harvesting and integrating nanowires are provided.
    Type: Grant
    Filed: April 29, 2005
    Date of Patent: March 4, 2008
    Assignee: Nanosys, Inc
    Inventors: Linda T. Romano, Jian Chen, Xiangfeng Duan, Robert S. Dubrow, Stephen A. Empedocles, Jay L. Goldman, James M. Hamilton, David L. Heald, Francesco Lemmi, Chunming Niu, Yaoling Pan, George Pontis, Vijendra Sahi, Erik C. Scher, David P. Stumbo, Jeffery A. Whiteford
  • Publication number: 20080041814
    Abstract: The present invention is directed to methods to harvest, integrate and exploit nanomaterials, and particularly elongated nanowire materials. The invention provides methods for harvesting nanowires that include selectively etching a sacrificial layer placed on a nanowire growth substrate to remove nanowires. The invention also provides methods for integrating nanowires into electronic devices that include placing an outer surface of a cylinder in contact with a fluid suspension of nanowires and rolling the nanowire coated cylinder to deposit nanowires onto a surface. Methods are also provided to deposit nanowires using an ink-jet printer or an aperture to align nanowires. Additional aspects of the invention provide methods for preventing gate shorts in nanowire based transistors. Additional methods for harvesting and integrating nanowires are provided.
    Type: Application
    Filed: August 16, 2007
    Publication date: February 21, 2008
    Applicant: NANOSYS, INC.
    Inventors: Linda Romano, Jian Chen, Xiangfeng Duan, Robert Dubrow, Stephen Empedocles, Jay Goldman, James Hamilton, David Heald, Francesco Lemmi, Chunming Niu, Yaoling Pan, George Pontis, Vijendra Sahi, Erik Scher, David Stumbo, Jeffery Whiteford
  • Publication number: 20080038520
    Abstract: The present invention is directed to systems and methods for nanowire growth and harvesting. In an embodiment, methods for nanowire growth and doping are provided, including methods for epitaxial oriented nanowire growth using a combination of silicon precursors, as well as us of patterned substrates to grow oriented nanowires. In a further aspect of the invention, methods to improve nanowire quality through the use of sacrifical growth layers are provided. In another aspect of the invention, methods for transferring nanowires from one substrate to another substrate are provided.
    Type: Application
    Filed: December 20, 2006
    Publication date: February 14, 2008
    Applicant: NANOSYS, Inc.
    Inventors: Yaoling Pan, Xiangfeng Duan, Robert Dubrow, Jay Goldman, Shahriar Mostarshed, Chunming Niu, Linda Romano, David Stumbo, Alice Fischer-Colbrie, Vijendra Sahi, Virginia Robbins
  • Publication number: 20080032134
    Abstract: Ligand compositions for use in preparing discrete coated nanostructures are provided, as well as the coated nanostructures themselves and devices incorporating same. Methods for post-deposition shell formation on a nanostructure and for reversibly modifying nanostructures are also provided. The ligands and coated nanostructures of the present invention are particularly useful for close packed nanostructure compositions, which can have improved quantum confinement and/or reduced cross-talk between nanostructures.
    Type: Application
    Filed: February 13, 2007
    Publication date: February 7, 2008
    Applicant: NANOSYS, Inc.
    Inventors: Jeffery Whiteford, Rhett Brewer, Mihai Buretea, Jian Chen, Karen Cruden, Xiangfeng Duan, William Freeman, David Heald, Francisco Leon, Chao Liu, Andreas Meisel, Kyu Min, J. Parce, Erik Scher
  • Publication number: 20080026532
    Abstract: Methods and apparatuses for nanoenabled memory devices and anisotropic charge carrying arrays are described. In an aspect, a memory device includes a substrate, a source region of the substrate, and a drain region of the substrate. A population of nanoelements is deposited on the substrate above a channel region, the population of nanolements in one embodiment including metal quantum dots. A tunnel dielectric layer is formed on the substrate overlying the channel region, and a metal migration barrier layer is deposited over the dielectric layer. A gate contact is formed over the thin film of nanoelements. The nanoelements allow for reduced lateral charge transfer. The memory device may be a single or multistate memory device.
    Type: Application
    Filed: September 5, 2007
    Publication date: January 31, 2008
    Applicant: NANOSYS, INC.
    Inventors: Xiangfeng Duan, Calvin Chow, David Heald, Chunming Niu, J. Parce, David Stumbo
  • Publication number: 20070281156
    Abstract: The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components.
    Type: Application
    Filed: March 21, 2006
    Publication date: December 6, 2007
    Applicant: President and Fellows of Harvard College
    Inventors: Charles Lieber, Xiangfeng Duan, Yi Cui, Yu Huang, Mark Gudiksen, Lincoln Lauhon, Jianfang Wang, Hongkun Park, Qingqiao Wei, Wenjie Liang, David Smith, Deli Wang, Zhaohui Zhong
  • Patent number: 7301199
    Abstract: The present invention relates generally to sub-microelectronic circuitry, and more particularly to nanometer-scale articles, including nanoscale wires which can be selectively doped at various locations and at various levels. In some cases, the articles may be single crystals. The nanoscale wires can be doped, for example, differentially along their length, or radially, and either in terms of identity of dopant, concentration of dopant, or both. This may be used to provide both n-type and p-type conductivity in a single item, or in different items in close proximity to each other, such as in a crossbar array. The fabrication and growth of such articles is described, and the arrangement of such articles to fabricate electronic, optoelectronic, or spintronic devices and components.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: November 27, 2007
    Assignee: President and Fellows of Harvard College
    Inventors: Charles M. Lieber, Xiangfeng Duan, Yi Cui, Yu Huang, Mark Gudiksen, Lincoln J. Lauhon, Jianfang Wang, Hongkun Park, Qingqiao Wei, Wenjie Liang, David C. Smith, Deli Wang, Zhaohui Zhong