Magnetic Thin Film Patents (Class 365/171)
  • Patent number: 8908429
    Abstract: A method and apparatus for stray magnetic field compensation in a non-volatile memory cell, such as a spin-torque transfer random access memory (STRAM). In some embodiments, a first tunneling barrier is coupled to a reference structure that has a perpendicular anisotropy and a first magnetization direction. A recording structure that has a perpendicular anisotropy is coupled to the first tunneling barrier and a nonmagnetic spacer layer. A compensation layer that has a perpendicular anisotropy and a second magnetization direction in substantial opposition to the first magnetization direction is coupled to the nonmagnetic spacer layer. Further, the memory cell is programmable to a selected resistance state with application of a current to the recording structure.
    Type: Grant
    Filed: March 4, 2013
    Date of Patent: December 9, 2014
    Assignee: Seagate Technology LLC
    Inventors: Dimitar V. Dimitrov, Olle Gunnar Heinonen, Dexin Wang, Haiwen Xi
  • Patent number: 8908425
    Abstract: A technique is provided for a thermally assisted magnetoresistive random access memory device. The device has a synthetic antiferromagnetic layer disposed on an antiferromagnetic layer. The synthetic antiferromagnetic layer has a first ferromagnetic storage layer, a non-magnetic coupling layer disposed on the first ferromagnetic storage layer, and a second ferromagnetic storage layer disposed on the non-magnetic coupling layer. A non-magnetic tunnel barrier is disposed on the second ferromagnetic storage layer, and a ferromagnetic sense layer is disposed on the non-magnetic tunnel barrier. A first ferromagnetic critical temperature of the first ferromagnetic storage layer is higher than an antiferromagnetic critical temperature of the antiferromagnetic layer, is higher than a second ferromagnetic critical temperature of the second ferromagnetic storage layer, and is higher than a third ferromagnetic critical temperature of the ferromagnetic sense layer.
    Type: Grant
    Filed: August 20, 2013
    Date of Patent: December 9, 2014
    Assignee: International Business Machines Corporation
    Inventors: Anthony J. Annunziata, Philip L. Trouilloud, Daniel Worledge
  • Patent number: 8908422
    Abstract: A magnetoelectric memory element includes a magnetic element having an easy magnetization axis aligned along a first axis, means for applying to the magnetic element a magnetic polarization field aligned along a second axis not parallel to the first axis, a piezoelectric or electrostrictive substrate mechanically coupled with the magnetic element, and first and second electrodes arranged to apply an electrical field to the substrate so that the substrate exerts, on said magnetic element, a non-isotropic mechanical stress of a main direction generally oriented along a distinct third axis coplanar with the first and second axes. The magnetic element exhibits, by a combined effect of the magnetic polarization field and the easy magnetization axis, two distinct states of stable equilibrium of magnetization, corresponding to two not mutually opposed magnetization directions. The non-isotropic mechanical stress is sufficiently intense to induce a switchover between the two distinct states.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: December 9, 2014
    Assignees: Centre National de la Recherche Scientifique, Ecole Centrale de Lille Cite Scientifique
    Inventors: Nicolas Tiercelin, Yannick Dusch, Philippe Jacques Pernod, Vladimir Preobrazhensky
  • Patent number: 8908415
    Abstract: A resistive memory cell includes a switch and a resistive switching device. The switch includes a first terminal connected to a select line and a gate terminal connected to a word line. The resistive switching device is connected between a second terminal of the switch and a bit line. The resistive switching device is resettable by having a positive bias applied to the word line and a negative bias applied to the bit line.
    Type: Grant
    Filed: March 1, 2013
    Date of Patent: December 9, 2014
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Chin-Chieh Yang, Wen-Ting Chu, Kuo-Chi Tu, Yu-Wen Liao, Chih-Yang Chang, Hsia-Wei Chen
  • Patent number: 8908423
    Abstract: A magnetoresistive effect element includes: a magnetization free layer having an invertible magnetization; an insulating layer being adjacent to the magnetization free layer; and a magnetization fixed layer being adjacent to the insulation layer and in an opposite side of the insulation layer to the magnetization free layer. The magnetization free layer includes: a first magnetization free layer being adjacent to the insulating layer and comprising Fe or Co; and a second magnetization free layer being adjacent to the first magnetization layer and comprising NiFeB.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: December 9, 2014
    Assignee: NEC Corporation
    Inventor: Hiroaki Honjou
  • Patent number: 8908424
    Abstract: The subject application describes systems and methods that drive magnetization switching through magnonic spin transfer torque. A spin current is provided to a first magnetic layer with a first magnetic state. The spin current facilitates magnetization switching via a magnonic spin transfer torque in a second magnetic layer with a second magnetic state that is separated from the first magnetic layer by an interface. Alternatively, a spin current is provided to a first magnetic domain with a first magnetic state. The spin current facilitates domain wall propagation via a magnonic spin transfer torque. The domain wall is between the first magnetic domain and a second magnetic domain in a second magnetic state.
    Type: Grant
    Filed: September 28, 2012
    Date of Patent: December 9, 2014
    Assignee: The Hong Kong University of Science and Technology
    Inventors: Xiangrong Wang, Peng Yan, Xiansi Wang
  • Patent number: 8907436
    Abstract: Provided are magnetic memory devices with a perpendicular magnetic tunnel junction. The device includes a magnetic tunnel junction including a free layer structure, a pinned layer structure, and a tunnel barrier therebetween. The pinned layer structure may include a first magnetic layer having an intrinsic perpendicular magnetization property, a second magnetic layer having an intrinsic in-plane magnetization property, and an exchange coupling layer interposed between the first and second magnetic layers. The exchange coupling layer may have a thickness maximizing an antiferromagnetic exchange coupling between the first and second magnetic layers, and the second magnetic layer may exhibit a perpendicular magnetization direction, due at least in part to the antiferromagnetic exchange coupling with the first magnetic layer.
    Type: Grant
    Filed: July 2, 2013
    Date of Patent: December 9, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: SeChung Oh, Ki Woong Kim, Younghyun Kim, Whankyun Kim, Sang Hwan Park
  • Patent number: 8902632
    Abstract: Hybrid resistive memory devices and methods of operating and manufacturing the same, include at least two resistive memory units. At least one of the at least two resistive memory units is a resistive memory unit configured to operate in a long-term plasticity state.
    Type: Grant
    Filed: December 18, 2012
    Date of Patent: December 2, 2014
    Assignees: Samsung Electronics Co., Ltd., Gwangju Institute of Science and Technology
    Inventors: Young-bae Kim, Hyun-sang Hwang, Chang-jung Kim
  • Patent number: 8902644
    Abstract: A magnetoresistive element 10 having a memory cell 100 according to the present invention contains a first lower terminal n1 and a second lower terminal n2 respectively connected to both ends of a conductive layer 3 whose longitudinal direction is different from the column direction (X direction). Further, the gates of the first transistors M1 respectively included in two memory cells among the plurality of memory cells 100 and adjacent to each other in a row direction (Y direction) are commonly connected to a first word line 14. As a result, without increase of the cell area, it becomes possible to reserve a margin in the dimension of the cell structure or in the process for MRMA.
    Type: Grant
    Filed: December 6, 2011
    Date of Patent: December 2, 2014
    Assignee: NEC Corporation
    Inventors: Noboru Sakimura, Ryusuke Nebashi, Tadahiko Sugibayashi
  • Patent number: 8902642
    Abstract: A semiconductor device includes a memory cell. The memory cell includes: a magnetic recording layer formed of ferromagnetic material; first and second magnetization fixed layers coupled to the magnetic recording layer; a plurality of reference layers opposed to the magnetic recording layer; and a plurality of tunnel barrier films respectively inserted between the magnetic recording layer and the reference layers. The first magnetization fixed layer has a magnetization fixed in a first direction, and the second magnetization fixed layer has a magnetization fixed in a second direction opposite to first direction. The reference layers each have a magnetization fixed in the first direction or the second direction. The reference layers and the tunnel barrier layers are positioned between the first and second magnetization fixed layers.
    Type: Grant
    Filed: July 18, 2012
    Date of Patent: December 2, 2014
    Assignee: Renesas Electronics Corporation
    Inventor: Hideki Mitou
  • Patent number: 8901685
    Abstract: Magnetic materials and uses thereof are provided. In one aspect, a magnetic film is provided. The magnetic film comprises superparamagnetic particles on at least one surface thereof. The magnetic film may be patterned and may comprise a ferromagnetic material. The superparamagnetic particles may be coated with a non-magnetic polymer and/or embedded in a non-magnetic host material. The magnetic film may have increased damping and/or decreased coercivity.
    Type: Grant
    Filed: April 20, 2007
    Date of Patent: December 2, 2014
    Assignee: International Business Machines Corporation
    Inventors: Snorri Thorgeir Ingvarsson, Philip Louis Trouilloud, Shouheng Sun, Roger Hilsen Koch, David William Abraham
  • Patent number: 8902643
    Abstract: A memory device includes a plurality of magnetic random access memory (MRAM) cells, a field line, and a field line controller configured to generate a write sequence that traverses the field line. The write sequence is for writing a multi-bit word to the plurality of MRAM cells. The multi-bit word includes a first subset of bits having a first polarity and a second subset of bits having a second polarity. The write sequence writes concurrently to at least a subset of the plurality of MRAM cells corresponding to the first subset of bits having the first polarity, then subsequently writes concurrently to a remaining subset of the plurality of MRAM cells corresponding to the second subset of bits having the second polarity.
    Type: Grant
    Filed: October 9, 2012
    Date of Patent: December 2, 2014
    Assignee: Crocus Technology Inc.
    Inventors: Neal Berger, Jean-Pierre Nozieres, Virgile Javerliac
  • Patent number: 8897064
    Abstract: Methods for performing parallel voltage and current compensation during reading and/or writing of memory cells in a memory array are described. In some embodiments, the compensation may include adjusting a bit line voltage and/or bit line reference current applied to a memory cell based on a memory array zone, a bit line layer, and a memory cell direction associated with the memory cell. The compensation may include adjusting the bit line voltage and/or bit line reference current on a per memory cell basis depending on memory cell specific characteristics. In some embodiments, a read/write circuit for reading and/or writing a memory cell may select a bit line voltage from a plurality of bit line voltage options to be applied to the memory cell based on whether the memory cell has been characterized as a strong, weak, or typical memory cell.
    Type: Grant
    Filed: April 16, 2014
    Date of Patent: November 25, 2014
    Assignee: Sandisk 3D LLC
    Inventors: Yingchang Chen, Pankaj Kalra, Chandrasekhar Gorta
  • Patent number: 8897061
    Abstract: An MTJ cell includes a first metal layer elongated in the X-direction; a second metal layer separated from the first metal layer and elongated in the Y-direction; a magnetic tunnel junction (MTJ) interposed between the overlapping parts of the first and second metal layers and having extended parts not covered by the second metal layer, the MTJ including a pinned layer, a barrier layer, and a storage layer sequentially laminated; and a yoke spanning across the second metal layer, with both ends in the X-direction contacting the top surface of the extended parts of the storage layer not covered by the second metal layer, either directly or through an insulator. The planar shapes of the MTJ and the yoke possess a quantum easy axis in the X-direction and Y-direction, respectively.
    Type: Grant
    Filed: January 29, 2013
    Date of Patent: November 25, 2014
    Assignee: QuantuMag Consultancy Corp.
    Inventor: Joichiro Ezaki
  • Patent number: 8895323
    Abstract: A method for forming MRAM (magnetoresistive random access memory) devices is provided. A bottom electrode assembly is formed. A magnetic junction assembly is formed, comprising, depositing a magnetic junction assembly layer over the bottom electrode assembly, forming a patterned mask over the magnetic junction assembly layer, etching the magnetic junction assembly layer to form the magnetic junction assembly with gaps, gap filling the magnetic junction assembly, and planarizing the magnetic junction assembly. A top electrode assembly is formed.
    Type: Grant
    Filed: December 14, 2012
    Date of Patent: November 25, 2014
    Assignee: Lam Research Corporation
    Inventor: Joydeep Guha
  • Patent number: 8890267
    Abstract: A method and system provide a magnetic junction usable in a magnetic device. The magnetic junction includes a pinned layer, a nonmagnetic spacer layer, and a free layer. The nonmagnetic spacer layer is between the pinned layer and the free layer. The free layer has a gradient in a critical switching current density (Jc0) such that a first Jc0 of a first portion of the free layer is lower than a second Jc0 of a second portion of the free layer. The second portion of the free layer is further from the nonmagnetic spacer layer than the first portion is. The magnetic junction is configured such that the free layer is switchable between a plurality of stable magnetic states when a write current is passed through the magnetic junction.
    Type: Grant
    Filed: December 3, 2012
    Date of Patent: November 18, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dmytro Apalkov, Vladimir Nikitin, Mohamad Towfik Krounbi
  • Patent number: 8890569
    Abstract: A method and system provide and program a nonvolatile logic device. The nonvolatile logic device includes input and output magnetic junctions and at least one magnetic junction between the input and output magnetic junctions. The input magnetic junction includes an input junction free layer having an input junction easy axis. The input magnetic junction may be switchable using a current driven through the magnetic junction. The output magnetic junction includes an output junction free layer having an output junction easy axis. Each of the magnetic junction(s) includes a free layer having an easy axis. The input magnetic junction is magnetically coupled to the output magnetic junction through the magnetic junction(s). In some aspects, the method includes switching the magnetic moment(s) of the input magnetic junction from a first state to a second state, applying and then removing magnetic field(s) along the hard axis of the at least one magnetic junction.
    Type: Grant
    Filed: July 25, 2012
    Date of Patent: November 18, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Dmytro Apalkov, Eugene Chen, Kaveh Milaninia
  • Patent number: 8891291
    Abstract: A magnetoresistive logic cell (MRLC) is described that includes two MTJs in series that share a common free layer (CFL). The relative magnetization orientations of the CFL and the switchable reference layer (SRL) in MTJ-1 dominate the overall resistance of the MRLC without regard to the fixed magnetization orientation of the nonswitchable reference layer in MTJ-2. High and low resistance states of the MRLC occurs based on the relative magnetization orientations of SRL and CFL. This behavior allows the MRLC to be used as a logical comparator. The CFL is switched by STT effect by application of selected relatively short voltage pulses that do not switch the SRL. A voltage-induced switching principle can be used with MRLC embodiments of the present invention to switch the SRL to parallel or anti-parallel with respect to the magnetization CFL in both perpendicular and in-plane anisotropy embodiments.
    Type: Grant
    Filed: February 22, 2013
    Date of Patent: November 18, 2014
    Assignee: Avalanche Technology, Inc.
    Inventors: Yuchen Zhou, Zihui Wang, Yiming Huai
  • Patent number: 8891290
    Abstract: A method and system for providing a magnetic junction residing on a substrate and usable in a magnetic device are described. The magnetic junction includes a first pinned layer, a first nonmagnetic spacer layer having a first thickness, a free layer, a second nonmagnetic spacer layer having a second thickness greater than the first thickness, and a second pinned layer. The first nonmagnetic spacer layer resides between the pinned layer and the free layer. The first pinned layer resides between the free layer and the substrate. The second nonmagnetic spacer layer is between the free layer and the second pinned layer. Further, the magnetic junction is configured such that the free layer is switchable between a plurality of stable magnetic states when a write current is passed through the magnetic junction.
    Type: Grant
    Filed: March 11, 2011
    Date of Patent: November 18, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Xueti Tang, Jing Wu
  • Patent number: 8891328
    Abstract: An antifuse according to an embodiment of the invention herein can include a depletion mode metal oxide semiconductor field effect transistor (“MOSFET”) having a conduction channel and a metal gate overlying the conduction channel. A cathode and an anode of the antifuse can be electrically coupled to the gate and spaced apart from one another in a direction the gate extends, such that the antifuse is programmable by driving a programming current between the cathode and the anode to cause material of the metal gate to migrate away. The gate may be configured such that, under appropriate biasing conditions, when the antifuse is unprogrammed, the conduction channel is turned on unless a voltage above a first threshold voltage is applied to the gate to turn off the conduction channel. The gate can be configured such that when the antifuse has been programmed, the conduction channel remains turned on even if a voltage above the first threshold voltage is applied between the gate and a source region of the MOSFET.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: November 18, 2014
    Assignee: International Business Machines Corporation
    Inventor: Yan-Zun Li
  • Patent number: 8885397
    Abstract: Magnetic random access memory (MRAM) element suitable for a thermally-assisted write operation and for a self-referenced read operation, including a magnetic tunnel junction portion having a first portion and a second portion, each portion including a storage layer, a sense layer, and a tunnel barrier layer; the magnetic tunnel junction further including an antiferromagnetic layer between the two storage layers and pinning a storage magnetization of each of the storage layers below a critical temperature, and freeing them at and above the critical temperature; such that, during a write operation, a free magnetization of each of the sense layer is magnetically saturable according to a direction of a write magnetic field when applied; and the storage magnetizations are switchable in a direction substantially parallel and corresponding to the direction of the saturated free magnetizations.
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: November 11, 2014
    Assignee: Crocus Technology SA
    Inventor: Ioan Lucian Prejbeanu
  • Patent number: 8885398
    Abstract: Spin current generators and systems and methods for employing spin current generators. A spin current generator may be configured to generate a spin current polarized in one direction, or a spin current selectively polarized in two directions. The spin current generator may by employed in spintronics applications, wherein a spin current is desired.
    Type: Grant
    Filed: June 6, 2013
    Date of Patent: November 11, 2014
    Assignee: Micron Technology, Inc.
    Inventors: Jun Liu, Gurtej Sandhu
  • Patent number: 8885395
    Abstract: A magnetoresistive logic cell (MRLC) is described that includes two MTJs in series that share a common free layer (CFL). The relative magnetization orientations of the CFL and the switchable reference layer (SRL) in MTJ-1 dominate the overall resistance of the MRLC without regard to the fixed magnetization orientation of the nonswitchable reference layer in MTJ-2. The high resistance state of the MRLC occurs when the switchable reference and common free layers have opposite magnetization orientations. The low resistance state occurs when the orientations are the same. This behavior allows the MRLC to be used as a logical comparator. The CFL is switched by STT effect by application of selected relatively short voltage pulses that do not switch the SRL. The SRL is switched with reference to the CFL by a voltage effect generated by a selected longer voltage pulse that does not switch the CFL.
    Type: Grant
    Filed: February 22, 2012
    Date of Patent: November 11, 2014
    Assignee: Avalanche Technology, Inc.
    Inventors: Yuchen Zhou, Zihui Wang, Yiming Huai, Rajiv Yadav Ranjan, Roger K. Malmhall
  • Patent number: 8885396
    Abstract: According to one embodiment, a memory device includes: a first signal line; a second signal line; a transistor; a memory region; and a conductive region. The transistor controls a conduction of each of a current in a first direction flowing between the first line and the second line and a current in a second direction opposite to the first direction. The memory region has a first magnetic tunnel junction element which is connected between the first line and one end of the transistor, a magnetization direction of which becomes parallel when a current not less than a first parallel threshold value flows in the first direction, and the magnetization direction of which becomes antiparallel when a current not less than a first antiparallel threshold value flows in the second direction. The conductive region is connected between the second line and the other end of the transistor.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: November 11, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takaya Yamanaka, Susumu Shuto
  • Patent number: 8885400
    Abstract: Methods for performing parallel voltage and current compensation during reading and/or writing of memory cells in a memory array are described. In some embodiments, the compensation may include adjusting a bit line voltage and/or bit line reference current applied to a memory cell based on a memory array zone, a bit line layer, and a memory cell direction associated with the memory cell. The compensation may include adjusting the bit line voltage and/or bit line reference current on a per memory cell basis depending on memory cell specific characteristics. In some embodiments, a read/write circuit for reading and/or writing a memory cell may select a bit line voltage from a plurality of bit line voltage options to be applied to the memory cell based on whether the memory cell has been characterized as a strong, weak, or typical memory cell.
    Type: Grant
    Filed: February 21, 2013
    Date of Patent: November 11, 2014
    Assignee: SanDisk 3D LLC
    Inventors: Yingchang Chen, Pankaj Kalra, Chandrasekhar Gorla
  • Patent number: 8878318
    Abstract: MTJ stack structures for an MRAM device include an MTJ stack having a pinned ferromagnetic layer over a pinning layer, a tunneling barrier layer over the pinned ferromagnetic layer, a free ferromagnetic layer over the tunneling barrier layer, a conductive oxide layer over the free ferromagnetic layer, and an oxygen-based cap layer over the conductive oxide layer.
    Type: Grant
    Filed: September 24, 2011
    Date of Patent: November 4, 2014
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Chih-Ming Chen, Ya-Chen Kao, Ming-Te Liu, Chung-Yi Yu, Cheng-Yuan Tsai, Chun-Jung Lin
  • Patent number: 8879314
    Abstract: Memory cell comprising two conductors, with a serially connected magnetic storage element and a Schottky diode between the two conductors. The Schottky diode provides a unidirectional conductive path between the two conductors and through the element. The Schottky diode is formed between a metal layer in one of the two conductors and a processed junction layer. Methods for process and for operation of the memory cell are also disclosed. The memory cell using the Schottky diode can be designed for high speed operation and with high density of integration. Advantageously, the junction layer can also be used as a hard mask for defining the individual magnetic storage element in the memory cell. The memory cell is particularly useful for magnetic random access memory (MRAM) circuits.
    Type: Grant
    Filed: June 6, 2011
    Date of Patent: November 4, 2014
    Assignee: III Holdings 1, LLC
    Inventor: Krishnakumar Mani
  • Patent number: 8879315
    Abstract: Provided is a storage element including a storage layer that holds information according to a magnetization state of a magnetic body, a magnetization fixing layer that has magnetization serving as a reference of the information stored in the storage layer, and an insulation layer that is formed of a non-magnetic body disposed between the storage layer and the magnetization fixing layer. The information is stored by reversing the magnetization of the storage layer using spin torque magnetization reversal occurring with a current flowing in a lamination direction of a layer configuration of the storage layer, the insulation layer, and the magnetization fixing layer, and a size of the storage layer is less than a size in which a direction of the magnetization is simultaneously changed.
    Type: Grant
    Filed: July 27, 2012
    Date of Patent: November 4, 2014
    Assignee: Sony Corporation
    Inventors: Kazutaka Yamane, Masanori Hosomi, Hiroyuki Ohmori, Kazuhiro Bessho, Yutaka Higo, Tetsuya Asayama, Hiroyuki Uchida
  • Patent number: 8879310
    Abstract: A semiconductor storage device according to the present embodiment includes a plurality of bit lines, a plurality of word lines, and a plurality of memory cells each including a storage element and a switching element which are connected in series between adjacently paired ones of the bit lines. Gates of the switching elements of the memory cells connected between one of the adjacently paired ones of the bit lines are respectively connected to different ones of the word lines. A plurality of the storage elements and a plurality of the switching elements of the adjacent memory cells are alternately connected in series.
    Type: Grant
    Filed: February 4, 2014
    Date of Patent: November 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Tsuneo Inaba
  • Patent number: 8878324
    Abstract: The present invention relates to a magnetoresistive element including a first magnetic layer, a second magnetic layer, a first nonmagnetic layer, a third magnetic layer. The first magnetic layer includes a magnetic film of MnxGey (77 atm %?x?82 atm %, 18 atm %?y?23 atm %, x+y=100 atm %). The first nonmagnetic layer is provided between the first magnetic layer and the second magnetic layer. The third magnetic layer is provided between the first magnetic layer and the first nonmagnetic layer or between the second magnetic layer and the first nonmagnetic layer, or is provided between the first magnetic layer and the first nonmagnetic layer and between the second magnetic layer and the first nonmagnetic layer. The third magnetic layer includes a Heusler alloy. The present invention also relates to a magnetic memory containing the magnetoresistive element.
    Type: Grant
    Filed: January 30, 2014
    Date of Patent: November 4, 2014
    Assignees: Kabushiki Kaisha Toshiba, Tohoku University
    Inventors: Yushi Kato, Tadaomi Daibou, Eiji Kitagawa, Takao Ochiai, Takahide Kubota, Shigemi Mizukami, Terunobu Miyazaki
  • Patent number: 8879308
    Abstract: A method of operating magneto-resistive random access memory (MRAM) cells includes providing an MRAM cell, which includes a magnetic tunneling junction (MTJ) device; and a selector comprising a source-drain path serially coupled to the MTJ device. The method further includes applying an overdrive voltage to a gate of the selector to turn on the selector.
    Type: Grant
    Filed: July 16, 2012
    Date of Patent: November 4, 2014
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Shine Chung, Tao-Wen Chung, Chun-Jung Lin, Yu-Jen Wang, Hung-Sen Wang
  • Patent number: 8879306
    Abstract: Memory circuit comprising an addressable magnetic tunnel junction (MTJ) stack, forming a magnetic storage element in the circuit. The MTJ stack comprises a tunnel oxide layer between a free layer and a fixed layer. A stress inducing layer is disposed adjacent to the free layer to provide tensile or compressive stress to the free layer, in order to manipulate a magnetic field that is required to write a bit into the MTJ stack. Method of using the memory circuit is also proposed.
    Type: Grant
    Filed: August 12, 2011
    Date of Patent: November 4, 2014
    Assignee: III Holdings 1, LLC
    Inventor: Krishnakumar Mani
  • Patent number: 8878317
    Abstract: A magnetoresistive element according to an embodiment includes: a first to third ferromagnetic layers, and a first nonmagnetic layer, the first and second ferromagnetic layers each having an axis of easy magnetization in a direction perpendicular to a film plane, the third ferromagnetic layer including a plurality of ferromagnetic oscillators generating rotating magnetic fields of different oscillation frequencies from one another. Spin-polarized electrons are injected into the first ferromagnetic layer and induce precession movements in the plurality of ferromagnetic oscillators of the third ferromagnetic layer by flowing a current between the first and third ferromagnetic layers, the rotating magnetic fields are generated by the precession movements and are applied to the first ferromagnetic layer, and at least one of the rotating magnetic fields assists a magnetization switching in the first ferromagnetic layer.
    Type: Grant
    Filed: August 16, 2011
    Date of Patent: November 4, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tadaomi Daibou, Minoru Amano, Daisuke Saida, Junichi Ito, Yuichi Ohsawa, Chikayoshi Kamata, Saori Kashiwada, Hiroaki Yoda
  • Patent number: 8873274
    Abstract: A memory cell includes a plug-type first electrode in a substrate, a magneto-resistive memory element disposed on the first electrode, and a second electrode disposed on the magneto-resistive memory element opposite the first electrode. The second electrode has an area of overlap with the magneto-resistive memory element that is greater than an area of overlap of the first electrode and the magneto-resistive memory element. The first surface may, for example, be substantially circular and have a diameter less than a minimum planar dimension (e.g., width) of the second surface. The magneto-resistive memory element may include a colossal magneto-resistive material, such as an insulating material with a perovskite phase and/or a transition metal oxide.
    Type: Grant
    Filed: April 15, 2013
    Date of Patent: October 28, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: In-Gyu Baek, Moon-Sook Lee, Dong-Chul Kim
  • Patent number: 8873280
    Abstract: A spin transfer torque random access memory includes a substance unit, a source line unit, an insulation unit, a transistor unit, a MTJ unit, and a bit line unit. The substance unit includes a substance layer. The source line unit includes a plurality of source lines formed inside the substance layer. The transistor unit includes a plurality of transistors respectively disposed on the source lines. Each transistor includes a source region formed on each corresponding source line, a drain region formed above the source region, a channel region formed between the source region and the drain region, and a surrounding gate region surrounding the source region, the drain region, and the channel region. The MTJ unit includes a plurality of MTJ structures respectively disposed on the transistors. The bit line unit includes at least one bit line disposed on the MTJ unit.
    Type: Grant
    Filed: October 27, 2011
    Date of Patent: October 28, 2014
    Assignee: Inotera Memories, Inc.
    Inventors: Tzung Han Lee, Chung-Lin Huang, Ron Fu Chu
  • Patent number: 8869436
    Abstract: The present disclosure provides one embodiment of a method for operating a resistive random access memory (RRAM) cell. The method includes performing a forming operation to the RRAM cell with a forming voltage; performing a number of set/reset operation cycles to the RRAM cell; and performing a recreating process to the RRAM cell to recover RRAM resistance by applying a recreating voltage. Each of the number of set/reset operation cycles includes a set operation with a set voltage. The recreating voltage is greater than the set voltage.
    Type: Grant
    Filed: February 27, 2013
    Date of Patent: October 28, 2014
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Chun-Yang Tsai, Yu-Wei Ting, Kuo-Ching Huang
  • Patent number: 8873273
    Abstract: A memory includes memory cells each storing data according to a change in a resistance state, and reference cells referred to in order to detect data stored in the memory cells. Sense amplifiers compare reference data in the reference cells with data in the memory cells to detect the data in the memory cells. A counter counts a number NH of the memory cells having a resistance higher than a resistance of each reference cell or a number NL of the memory cells having a resistance lower than the resistance of each reference cell based on a result of detecting first logical data stored in the memory cells using each reference cell storing the first logical data. A determining part determines one of the reference cells as an optimum reference cell used in an actual data reading operation based on the number NH or NL for the reference cells.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: October 28, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Yoshihiro Ueda
  • Patent number: 8872686
    Abstract: The present disclosure relates to a method and architecture to minimize a transient glitch within a current digital-to-analog converter (DAC) comprising an array of identical current unit cells. The current DAC is configured with individual column decoders for even and odd rows of current unit cells, thus allowing for independent control of adjacent rows. The even row and odd row column decoders further comprise thermal decoders with coupled timing encoding which establishes synergy between an adjacent pair of rows. As current units cells within an active row are activated across the row by a counting up of a first column decoder, the current units cells within a next row adjacent the active row are returned to an initial state of the active row by counting down in a second column decoder. Other devices and methods are also disclosed.
    Type: Grant
    Filed: April 8, 2013
    Date of Patent: October 28, 2014
    Assignee: Taiwan Semiconductor Manufacturing Co., Ltd.
    Inventors: Kuo-Yu Chou, Wei Lun Tao, Shang-Fu Yeh, Yi-Che Chen, Calvin Yi-Ping Chao
  • Patent number: 8873328
    Abstract: A nonvolatile memory device includes a memory cell array comprising memory cells connected to bit lines and word lines; a word line decoder configured to apply word line voltages to the word lines; a bit line selector configured to select at least one bit line of the bit lines; a control logic configured to control the word line decoder and the bit line selector so that write data is programmed in the memory cell array; and a sudden power off (SPO) detection circuit, wherein the SPO detection circuit comprises: a sensing cell; a first driver configured to provide a first voltage to the sensing cell; and a second driver configured to provide a second voltage to the sensing cell, wherein a program state of the sensing cell becomes different depending on an order or a time difference between the first driver and the second driver being powered off.
    Type: Grant
    Filed: September 26, 2013
    Date of Patent: October 28, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Yong Shik Shin, Yunseok Yang, Oh-Seong Kwon
  • Patent number: 8865326
    Abstract: A layered ferromagnetic structure is composed of a first ferromagnetic layer positioned over a substrate; a second ferromagnetic layer positioned over the first ferromagnetic layer; and a first non-magnetic layer placed between the first and second ferromagnetic layers. The top surface of the first ferromagnetic layer is in contact with the first non-magnetic layer. The first ferromagnetic layer includes a first orientation control buffer that exhibits an effect of enhancing crystalline orientation of a film formed thereon.
    Type: Grant
    Filed: July 12, 2010
    Date of Patent: October 21, 2014
    Assignee: NEC Corporation
    Inventors: Yoshiyuki Fukumoto, Chuuji Igarashi
  • Patent number: 8866242
    Abstract: A memory device may comprise a magnetic tunnel junction (MTJ) stack, a bottom electrode (BE) layer, and a contact layer. The MTJ stack may include a free layer, a barrier, and a pinned layer. The BE layer may be coupled to the MTJ stack, and encapsulated in a planarized layer. The BE layer may also have a substantial common axis with the MTJ stack. The contact layer may be embedded in the BE layer, and form an interface between the BE layer and the MTJ stack.
    Type: Grant
    Filed: November 10, 2011
    Date of Patent: October 21, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Xia Li, Seung H. Kang, Matthew M. Nowak
  • Patent number: 8867266
    Abstract: Disclosed herein is a method for driving a storage element that has a plurality of magnetic layers and performs recording by utilizing spin torque magnetization reversal, the method including applying a pulse voltage having reverse polarity of polarity of a recording pulse voltage in application of the recording pulse voltage to the storage element.
    Type: Grant
    Filed: May 10, 2011
    Date of Patent: October 21, 2014
    Assignee: Sony Corporation
    Inventors: Kazuhiro Bessho, Masanori Hosomi, Hiroyuki Ohmori, Yutaka Higo, Kazutaka Yamane, Hiroyuki Uchida
  • Patent number: 8861244
    Abstract: A non-volatile memory cell array and associated method of use. In accordance with various embodiments, the array includes a plurality of programmable resistive sense elements (RSEs) coupled to a shared switching device. The switching device has a common source region and multiple drain regions, each drain region connected to an associated RSE from said plurality of RSEs.
    Type: Grant
    Filed: March 1, 2011
    Date of Patent: October 14, 2014
    Assignee: Seagate Technology LLC
    Inventors: Andrew John Carter, Maroun Georges Khoury, Yong Lu, Roger Glenn Rolbiecki
  • Patent number: 8861252
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device comprises a memory cell which includes a variable resistance element and a current-limiting element that has a nonlinear current-voltage characteristic and a driver which changes the resistance of the variable resistance element by causing a first current to flow in the memory cell. In addition, the nonvolatile semiconductor memory device further comprises a detection module which detects a change in the resistance of the memory cell based on the magnitude of the first current and a current supplying module which causes a second current to flow in the detection module in place of the first current.
    Type: Grant
    Filed: September 16, 2011
    Date of Patent: October 14, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Hiroshi Ito
  • Patent number: 8861263
    Abstract: A semiconductor memory device includes a memory cell unit including a plurality of memory cells coupled between a plurality of word lines and a plurality of bit lines, and configured to provide a read value in response to an activated word line, a reference value generating unit including a plurality of reference value generating cells coupled between the plurality of word lines and a reference bit line, and configured to provide a single reference value in response to the activated word line, and a sense circuit configured to provide a sense output signal based on the single reference value and the read value.
    Type: Grant
    Filed: December 17, 2012
    Date of Patent: October 14, 2014
    Assignee: SK Hynix Inc.
    Inventor: Seung Hyun Lee
  • Patent number: 8860159
    Abstract: A spintronic electronic apparatus having a multilayer structure. The apparatus includes a substrate, having disposed in succession upon the substrate; a bottom interface layer; a pinned layer; a tunneling barrier; a free layer; and a top interface layer, wherein the apparatus operates as a non-resonant magnetic tunnel junction in a large amplitude, out-of-plane magnetization precession regime having weakly current dependent, large diode volt-watt sensitivity when external microwave signals that exceed a predetermined threshold current and have a frequency that is lower than a predetermined level excite the magnetization precession.
    Type: Grant
    Filed: October 20, 2011
    Date of Patent: October 14, 2014
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Thomas J. Meitzler, Elena N. Bankowski, Michael Nranian, Ilya N. Krivorotov, Andrei N. Slavin, Vasyl S. Tyberkevych
  • Patent number: 8861262
    Abstract: A spin-current switchable magnetic memory element includes a plurality of magnetic layers including a perpendicular magnetic anisotropy component, at least one of the plurality of magnetic layers including an alloy of a rare-earth metal and a transition metal, and at least one barrier layer formed adjacent to at least one of the plurality of magnetic layers.
    Type: Grant
    Filed: September 14, 2012
    Date of Patent: October 14, 2014
    Assignee: International Business Machines Corporation
    Inventors: Jonathan Zanhong Sun, Stuart Stephen Papworth Parkin
  • Patent number: 8860158
    Abstract: A STTMRAM element includes a magnetization layer made of a first free layer and a second free layer, separated by a non-magnetic separation layer (NMSL), with the first and second free layers each having in-plane magnetizations that act on each other through anti-parallel coupling. The direction of the magnetization of the first and second free layers each is in-plane prior to the application of electrical current to the STTMRAM element and thereafter, the direction of magnetization of the second free layer becomes substantially titled out-of-plane and the direction of magnetization of the first free layer switches. Upon electrical current being discontinued to the STTMRAM element, the direction of magnetization of the second free layer remains in a direction that is substantially opposite to that of the first free layer.
    Type: Grant
    Filed: June 19, 2013
    Date of Patent: October 14, 2014
    Assignee: Avalanche Technology, Inc.
    Inventors: Yuchen Zhou, Yiming Huai, Jing Zhang, Rajiv Yadav Ranjan, Roger Klas Malmhall
  • Patent number: 8860155
    Abstract: The present disclosure relates to a magnetic tunnel junction (MTJ) device and its fabricating method. Through forming MTJ through a damascene process, device damage due to the etching process and may be avoided. In some embodiments, a spacer is formed between a first portion and a second portion of the MTJ to prevent the tunnel insulating layer of the MTJ from being damaged in subsequent processes, greatly increasing product yield thereby. In other embodiments, signal quality may be improved and magnetic flux leakage may be reduced through the improved cup-shaped MTJ structure of this invention.
    Type: Grant
    Filed: March 22, 2012
    Date of Patent: October 14, 2014
    Assignee: Semiconductor Manufacturing International (Beijing) Corporation
    Inventors: Chi Min-Hwa, Mieno Fumitake
  • Patent number: 8860156
    Abstract: A synthetic antiferromagnetic (SAF) structure for a spintronic device is disclosed and has an AP2/antiferromagnetic (AF) coupling/CoFeB configuration. The SAF structure is thinned to reduce the fringing (Ho) field while maintaining high coercivity. The AP2 reference layer has intrinsic perpendicular magnetic anisotropy (PMA) and induces PMA in a thin CoFeB layer through AF coupling. In one embodiment, AF coupling is improved by inserting a Co dusting layer on top and bottom surfaces of a Ru AF coupling layer. When AP2 is (Co/Ni)4, and CoFeB thickness is 7.5 Angstroms, Ho is reduced to 125 Oe, Hc is 1000 Oe, and a balanced saturation magnetization-thickness product (Mst)=0.99 is achieved. The SAF structure may also be represented as FL2/AF coupling/CoFeB where FL2 is a ferromagnetic layer with intrinsic PMA.
    Type: Grant
    Filed: September 11, 2012
    Date of Patent: October 14, 2014
    Assignee: Headway Technologies, Inc.
    Inventors: Robert Beach, Guenole Jan, Yu-Jen Wang, Ru-Ying Tong