Patents by Inventor James D. Plummer

James D. Plummer 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).

  • Patent number: 10435814
    Abstract: A single-crystalline metal is created on a substrate by liquefying a metal material contained within a crucible while in contact with a surface of the substrate, cooling the metal material by causing a temperature gradient effected in the substrate in a direction that is neutral along the surface of the substrate and, therein, growing the single-crystalline metal in the crucible.
    Type: Grant
    Filed: October 31, 2016
    Date of Patent: October 8, 2019
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: James D. Plummer, Kai Zhang, Xue Bai Pitner, Jonathan A. Fan
  • Publication number: 20170121843
    Abstract: A single-crystalline metal is created on a substrate by liquefying a metal material contained within a crucible while in contact with a surface of the substrate, cooling the metal material by causing a temperature gradient effected in the substrate in a direction that is neutral along the surface of the substrate and, therein, growing the single-crystalline metal in the crucible.
    Type: Application
    Filed: October 31, 2016
    Publication date: May 4, 2017
    Inventors: James D. Plummer, Kai Zhang, Xue Bai Pitner, Jonathan A. Fan
  • Patent number: 7858449
    Abstract: In a method of fabricating a semiconductor memory device, a thyristor may be formed in a layer of semiconductor material. Carbon may be implanted and annealed in a base-emitter junction region for the thyristor to affect leakage characteristics. The density of the carbon and/or a bombardment energy and/or an anneal therefore may be selected to establish a low-voltage, leakage characteristic for the junction substantially greater than its leakage absent the carbon. In one embodiment, an anneal of the implanted carbon may be performed in common with an activation for other implant regions the semiconductor device.
    Type: Grant
    Filed: February 9, 2009
    Date of Patent: December 28, 2010
    Assignee: T-RAM Semiconductor, Inc.
    Inventors: Kevin J. Yang, Farid Nemati, Scott Robins, James D. Plummer, Hyun-Jin Cho
  • Patent number: 7749872
    Abstract: Single-crystalline growth is realized using a liquid-phase crystallization approach involving the inhibition of defects typically associated with liquid-phase crystalline growth of lattice mismatched materials. According to one example embodiment, a semiconductor device structure includes a substantially single-crystal region. A liquid-phase material, such as Ge or a semiconductor compound, is crystallized to form the single-crystal region using an approach involving defect inhibition for the promotion of single-crystalline growth. In some instances, this defect inhibition involves the reduction and/or elimination of defects using a relatively small physical opening via which a crystalline growth front propagates. In other instances, this defect inhibition involves causing a change in crystallization front direction relative to a crystallization seed location.
    Type: Grant
    Filed: February 25, 2009
    Date of Patent: July 6, 2010
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: James D. Plummer, Peter B. Griffin, Jia Feng, Shu-Lu Chen
  • Patent number: 7592642
    Abstract: A thyristor-based memory device may comprise two base regions of opposite type conductivity formed between a cathode-emitter region and an anode-emitter region. A junction defined between the p-base region and the cathode-emitter region of the thyristor may be “treated” with a high ionization energy acceptor such as indium in combination with carbon as an activation assist species. These two implants may form complexes that may extend across the junction region.
    Type: Grant
    Filed: April 4, 2006
    Date of Patent: September 22, 2009
    Assignee: T-RAM Semiconductor, Inc.
    Inventors: Srinivasa R. Banna, James D. Plummer
  • Publication number: 20090176353
    Abstract: Single-crystalline growth is realized using a liquid-phase crystallization approach involving the inhibition of defects typically associated with liquid-phase crystalline growth of lattice mismatched materials. According to one example embodiment, a semiconductor device structure includes a substantially single-crystal region. A liquid-phase material, such as Ge or a semiconductor compound, is crystallized to form the single-crystal region using an approach involving defect inhibition for the promotion of single-crystalline growth. In some instances, this defect inhibition involves the reduction and/or elimination of defects using a relatively small physical opening via which a crystalline growth front propagates. In other instances, this defect inhibition involves causing a change in crystallization front direction relative to a crystallization seed location.
    Type: Application
    Filed: February 25, 2009
    Publication date: July 9, 2009
    Inventors: James D. Plummer, Peter B. Griffin, Jia Feng, Shu-Lu Chen
  • Publication number: 20090162979
    Abstract: In a method of fabricating a semiconductor memory device, a thyristor may be formed in a layer of semiconductor material. Carbon may be implanted and annealed in a base-emitter junction region for the thyristor to affect leakage characteristics. The density of the carbon and/or a bombardment energy and/or an anneal therefore may be selected to establish a low-voltage, leakage characteristic for the junction substantially greater than its leakage absent the carbon. In one embodiment, an anneal of the implanted carbon may be performed in common with an activation for other implant regions the semiconductor device.
    Type: Application
    Filed: February 9, 2009
    Publication date: June 25, 2009
    Inventors: Kevin J. Yang, Farid Nemati, Scott Robins, James D. Plummer, Hyun-Jin Cho
  • Patent number: 7508701
    Abstract: Negative differential resistance devices are implemented to facilitate current flow under different operating conditions. According to an example embodiment of the present invention, an NDR device is arranged for selective passage of current through relatively high tunneling efficiency regions and relatively low tunneling efficiency regions. In some applications, a gate is used to accumulate carriers to facilitate the passage of current that is predominantly one of tunneling current and generation current, respectively, by controlling the passage of current through a relatively high tunneling efficiency region and a relatively low tunneling efficiency region. In some implementations, the NDR device is arranged to mitigate leakage in a storage device using a two-terminal connection.
    Type: Grant
    Filed: November 29, 2006
    Date of Patent: March 24, 2009
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Yue Liang, Kailash Gopalakrishnan, Peter Griffin, James D. Plummer
  • Patent number: 7498243
    Abstract: Single-crystalline growth is realized using a liquid-phase crystallization approach involving the inhibition of defects typically associated with liquid-phase crystalline growth of lattice mismatched materials. According to one example embodiment, a semiconductor device structure includes a substantially single-crystal region. A liquid-phase material is crystallized to form the single-crystal region using an approach involving defect inhibition for the promotion of single-crystalline growth. In some instances, this defect inhibition involves the reduction and/or elimination of defects using a relatively small physical opening via which a crystalline growth front propagates. In other instances, this defect inhibition involves causing a change in crystallization front direction relative to a crystallization seed location.
    Type: Grant
    Filed: March 17, 2004
    Date of Patent: March 3, 2009
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Yaocheng Liu, Michael D. Deal, James D. Plummer
  • Patent number: 7488626
    Abstract: In a method of fabricating a semiconductor memory device, a thyristor may be formed in a layer of semiconductor material. Carbon may be implanted and annealed in a base-emitter junction region for the thyristor to affect leakage characteristics. The density of the carbon and/or a bombardment energy and/or an anneal therefore may be selected to establish a low-voltage, leakage characteristic for the junction substantially greater than its leakage absent the carbon. In one embodiment, an anneal of the implanted carbon may be performed in common with an activation for other implant regions the semiconductor device.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: February 10, 2009
    Assignee: T-RAM Semiconductor, Inc.
    Inventors: Kevin J. Yang, Farid Nemati, Scott Robins, James D. Plummer, Hyun-Jin Cho
  • Patent number: 7365373
    Abstract: A thyristor device can be used to implement a variety of semiconductor memory circuits, including high-density memory-cell arrays and single cell circuits. In one example embodiment, the thyristor device includes doped regions of opposite polarity, and a first word line that is used to provide read and write access to the memory cell. A second word line is located adjacent to and separated by an insulative material from one of the doped regions of the thyristor device for write operations to the memory cell, for example, by enhancing the switching of the thyristor device from a high conductance state to a low conductance state and/or from the low conductance state to the high conductance. This type of memory circuit can be implemented to significantly reduce standby power consumption and access time.
    Type: Grant
    Filed: August 18, 2005
    Date of Patent: April 29, 2008
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Farid Nemati, James D. Plummer
  • Patent number: 7195959
    Abstract: A thyristor-based semiconductor memory device may comprise at least a region thereof, e.g., a p-base region, having high ionization energy impurity, such as a dopant. This high ionization energy impurity within a base region may be operable to compensate for a gain-versus-temperature dependence of a constituent bipolar transistor of the thyristor element of a thyristor-based memory device. In particular embodiments, the high ionization energy impurity may include a donor and/or acceptor in silicon.
    Type: Grant
    Filed: October 4, 2004
    Date of Patent: March 27, 2007
    Assignee: T-Ram Semiconductor, Inc.
    Inventors: James D. Plummer, Zachary K. Lee, Kevin J. Yang, Farid Nemati
  • Patent number: 7075122
    Abstract: In a method of fabricating a semiconductor memory device, a thyristor may be formed in a layer of semiconductor material. Carbon may be implanted and annealed in a base-emitter junction region for the thyristor to affect leakage characteristics. The density of the carbon and/or a bombardment energy and/or an anneal therefore may be selected to establish a low-voltage, leakage characteristic for the junction substantially greater than its leakage absent the carbon. In one embodiment, an anneal of the implanted carbon may be performed in common with an activation for other implant regions the semiconductor device.
    Type: Grant
    Filed: September 25, 2003
    Date of Patent: July 11, 2006
    Assignee: T-Ram Semiconductor, Inc.
    Inventors: Kevin J. Yang, Farid Nemati, Scott Robins, James D. Plummer, Hyun-Jin Cho
  • Patent number: 6967358
    Abstract: A thyristor device can be used to implement a variety of semiconductor memory circuits, including high-density memory-cell arrays and single cell circuits. In one example embodiment, the thyristor device includes doped regions of opposite polarity, and a first word line that is used to provide read and write access to the memory cell. A second word line is located adjacent to and separated by an insulative material from one of the doped regions of the thyristor device for write operations to the memory cell, for example, by enhancing the switching of the thyristor device from a high conductance state to a low conductance state and/or from the low conductance state to the high conductance. This type of memory circuit can be implemented to significantly reduce standby power consumption and access time.
    Type: Grant
    Filed: February 12, 2004
    Date of Patent: November 22, 2005
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Farid Nemati, James D. Plummer
  • Publication number: 20040159853
    Abstract: A thyristor device can be used to implement a variety of semiconductor memory circuits, including high-density memory-cell arrays and single cell circuits. In one example embodiment, the thyristor device includes doped regions of opposite polarity, and a first word line that is used to provide read and write access to the memory cell. A second word line is located adjacent to and separated by an insulative material from one of the doped regions of the thyristor device for write operations to the memory cell, for example, by enhancing the switching of the thyristor device from a high conductance state to a low conductance state and/or from the low conductance state to the high conductance. This type of memory circuit can be implemented to significantly reduce standby power consumption and access time.
    Type: Application
    Filed: February 12, 2004
    Publication date: August 19, 2004
    Inventors: Farid Nemati, James D. Plummer
  • Patent number: 6727529
    Abstract: A novel capacitively coupled NDR device can be used to implement a variety of semiconductor circuits, including high-density SRAM cells and power thyristor structures. In one example embodiment, the NDR device is used as a thin vertical PNPN structure with capacitively-coupled gate-assisted turn-off and turn-on mechanisms. An SRAM based on this new device is comparable in cell area, standby current, architecture, speed, and fabrication process to a DRAM of the same capacity. In one embodiment, an NDR-based SRAM cell consists of only two elements, has an 8 F2 footprint, can operate at high speeds and low voltages, has a good noise-margin, and is compatible in fabrication process with main-stream CMOS. This cell significantly reduces standby power consumption compared to other types of NDR-based SRAMs.
    Type: Grant
    Filed: March 20, 2002
    Date of Patent: April 27, 2004
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Farid Nemati, James D. Plummer
  • Patent number: 6528356
    Abstract: A novel capacitively coupled NDR device can be used to implement a variety of semiconductor circuits, including high-density SRAM cells and power thyristor structures. In one example embodiment, the NDR device is used as a thin vertical PNPN structure with capacitively-coupled gate-assisted turn-off and turn-on mechanisms. An SRAM based on this new device is comparable in cell area, standby current, architecture, speed, and fabrication process to a DRAM of the same capacity. In one embodiment, an NDR-based SRAM cell consists of only two elements, has an 8 F2 footprint, can operate at high speeds and low voltages, has a good noise-margin, and is compatible in fabrication process with main-stream CMOS. This cell significantly reduces standby power consumption compared to other types of NDR-based SRAMs.
    Type: Grant
    Filed: March 20, 2002
    Date of Patent: March 4, 2003
    Assignee: The Board of Trustees of the Leland Stanford Junior University
    Inventors: Farid Nemati, James D. Plummer
  • Patent number: 6448586
    Abstract: A novel capacitively coupled NDR device can be used to implement a variety of semiconductor circuits, including high-density SRAM cells and power thyristor structures. In one example embodiment, the NDR device is used as a thin vertical PNPN structure with capacitively-coupled gate-assisted turn-off and turn-on mechanisms. An SRAM based on this new device is comparable in cell area, standby current, architecture, speed, and fabrication process to a DRAM of the same capacity. In one embodiment, an NDR-based SRAM cell consists of only two elements, has an 8F2 footprint, can operate at high speeds and low voltages, has a good noise-margin, and is compatible in fabrication process with main-stream CMOS. This cell significantly reduces standby power consumption compared to other type of NDR-based SRAMs.
    Type: Grant
    Filed: September 21, 2000
    Date of Patent: September 10, 2002
    Assignee: The Board of Trustees of the Leland Standford Junior University
    Inventors: Farid Nemati, James D. Plummer
  • Publication number: 20020096690
    Abstract: A novel capacitively coupled NDR device can be used to implement a variety of semiconductor circuits, including high-density SRAM cells and power thyristor structures. In one example embodiment, the NDR device is used as a thin vertical PNPN structure with capacitively-coupled gate-assisted turn-off and turn-on mechanisms. An SRAM based on this new device is comparable in cell area, standby current, architecture, speed, and fabrication process to a DRAM of the same capacity. In one embodiment, an NDR-based SRAM cell consists of only two elements, has an 8 F2 footprint, can operate at high speeds and low voltages, has a good noise-margin, and is compatible in fabrication process with main-stream CMOS. This cell significantly reduces standby power consumption compared to other types of NDR-based SRAMs.
    Type: Application
    Filed: March 20, 2002
    Publication date: July 25, 2002
    Applicant: Stanford University
    Inventors: Farid Nemati, James D. Plummer
  • Publication number: 20020096689
    Abstract: A novel capacitively coupled NDR device can be used to implement a variety of semiconductor circuits, including high-density SRAM cells and power thyristor structures. In one example embodiment, the NDR device is used as a thin vertical PNPN structure with capacitively-coupled gate-assisted turn-off and turn-on mechanisms. An SRAM based on this new device is comparable in cell area, standby current, architecture, speed, and fabrication process to a DRAM of the same capacity. In one embodiment, an NDR-based SRAM cell consists of only two elements, has an 8 F2 footprint, can operate at high speeds and low voltages, has a good noise-margin, and is compatible in fabrication process with main-stream CMOS. This cell significantly reduces standby power consumption compared to other types of NDR-based SRAMs.
    Type: Application
    Filed: March 20, 2002
    Publication date: July 25, 2002
    Applicant: Stanford University
    Inventors: Farid Nemati, James D. Plummer