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: 10435814Abstract: 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: GrantFiled: October 31, 2016Date of Patent: October 8, 2019Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: James D. Plummer, Kai Zhang, Xue Bai Pitner, Jonathan A. Fan
-
Publication number: 20170121843Abstract: 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: ApplicationFiled: October 31, 2016Publication date: May 4, 2017Inventors: James D. Plummer, Kai Zhang, Xue Bai Pitner, Jonathan A. Fan
-
Patent number: 7858449Abstract: 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: GrantFiled: February 9, 2009Date of Patent: December 28, 2010Assignee: T-RAM Semiconductor, Inc.Inventors: Kevin J. Yang, Farid Nemati, Scott Robins, James D. Plummer, Hyun-Jin Cho
-
Patent number: 7749872Abstract: 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: GrantFiled: February 25, 2009Date of Patent: July 6, 2010Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: James D. Plummer, Peter B. Griffin, Jia Feng, Shu-Lu Chen
-
Patent number: 7592642Abstract: 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: GrantFiled: April 4, 2006Date of Patent: September 22, 2009Assignee: T-RAM Semiconductor, Inc.Inventors: Srinivasa R. Banna, James D. Plummer
-
Publication number: 20090176353Abstract: 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: ApplicationFiled: February 25, 2009Publication date: July 9, 2009Inventors: James D. Plummer, Peter B. Griffin, Jia Feng, Shu-Lu Chen
-
Publication number: 20090162979Abstract: 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: ApplicationFiled: February 9, 2009Publication date: June 25, 2009Inventors: Kevin J. Yang, Farid Nemati, Scott Robins, James D. Plummer, Hyun-Jin Cho
-
Patent number: 7508701Abstract: 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: GrantFiled: November 29, 2006Date of Patent: March 24, 2009Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Yue Liang, Kailash Gopalakrishnan, Peter Griffin, James D. Plummer
-
Patent number: 7498243Abstract: 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: GrantFiled: March 17, 2004Date of Patent: March 3, 2009Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Yaocheng Liu, Michael D. Deal, James D. Plummer
-
Patent number: 7488626Abstract: 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: GrantFiled: July 10, 2006Date of Patent: February 10, 2009Assignee: T-RAM Semiconductor, Inc.Inventors: Kevin J. Yang, Farid Nemati, Scott Robins, James D. Plummer, Hyun-Jin Cho
-
Patent number: 7365373Abstract: 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: GrantFiled: August 18, 2005Date of Patent: April 29, 2008Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Farid Nemati, James D. Plummer
-
Patent number: 7195959Abstract: 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: GrantFiled: October 4, 2004Date of Patent: March 27, 2007Assignee: T-Ram Semiconductor, Inc.Inventors: James D. Plummer, Zachary K. Lee, Kevin J. Yang, Farid Nemati
-
Patent number: 7075122Abstract: 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: GrantFiled: September 25, 2003Date of Patent: July 11, 2006Assignee: T-Ram Semiconductor, Inc.Inventors: Kevin J. Yang, Farid Nemati, Scott Robins, James D. Plummer, Hyun-Jin Cho
-
Patent number: 6967358Abstract: 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: GrantFiled: February 12, 2004Date of Patent: November 22, 2005Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Farid Nemati, James D. Plummer
-
Publication number: 20040159853Abstract: 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: ApplicationFiled: February 12, 2004Publication date: August 19, 2004Inventors: Farid Nemati, James D. Plummer
-
Patent number: 6727529Abstract: 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: GrantFiled: March 20, 2002Date of Patent: April 27, 2004Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Farid Nemati, James D. Plummer
-
Patent number: 6528356Abstract: 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: GrantFiled: March 20, 2002Date of Patent: March 4, 2003Assignee: The Board of Trustees of the Leland Stanford Junior UniversityInventors: Farid Nemati, James D. Plummer
-
Patent number: 6448586Abstract: 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: GrantFiled: September 21, 2000Date of Patent: September 10, 2002Assignee: The Board of Trustees of the Leland Standford Junior UniversityInventors: Farid Nemati, James D. Plummer
-
Publication number: 20020096690Abstract: 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: ApplicationFiled: March 20, 2002Publication date: July 25, 2002Applicant: Stanford UniversityInventors: Farid Nemati, James D. Plummer
-
Publication number: 20020096689Abstract: 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: ApplicationFiled: March 20, 2002Publication date: July 25, 2002Applicant: Stanford UniversityInventors: Farid Nemati, James D. Plummer