Magnetic-field-controlled Resistors (epo) Patents (Class 257/E43.004)
  • Patent number: 8227896
    Abstract: Nitrogen-doped MgO insulating layers exhibit voltage controlled resistance states, e.g., a high resistance and a low resistance state. Patterned nano-devices on the 100 nm scale show highly reproducible switching characteristics. The voltage levels at which such devices are switched between the two resistance levels can be systematically lowered by increasing the nitrogen concentration. Similarly, the resistance of the high resistance state can be varied by varying the nitrogen concentration, and decreases by orders of magnitude by varying the nitrogen concentrations by a few percent. On the other hand, the resistance of the low resistance state is nearly insensitive to the nitrogen doping level. The resistance of single Mg50O50-xNx layer devices can be varied over a wide range by limiting the current that can be passed during the SET process. Associated data storage devices can be constructed.
    Type: Grant
    Filed: December 11, 2009
    Date of Patent: July 24, 2012
    Assignee: International Business Machines Corporation
    Inventors: Xin Jiang, Stuart Stephen Papworth Parkin, Mahesh Govind Samant, Cheng-Han Yang
  • Patent number: 8207587
    Abstract: A magnetic sensor for detecting magnetism in two-axial directions or three-axial directions is constituted of a substrate, a silicon oxide film that is formed on the substrate so as to form the planar surface and slopes, a plurality of magnetoresistive elements, each of which is formed by laminating a free layer, a conductive layer, and a pin layer on the substrate, a plurality of lead films that are formed to connect the magnetoresistive elements in series, a CVD oxide film for covering the magnetoresistive elements, and a non-magnetic film that is formed between the magnetoresistive elements and the CVD oxide film so as to cover the periphery of the free layer with respect to each magnetoresistive element. Thus, it is possible for the magnetic sensor to include the magnetoresistive elements having superior hysteresis characteristics.
    Type: Grant
    Filed: June 11, 2008
    Date of Patent: June 26, 2012
    Assignee: Yamaha Corporation
    Inventor: Kokichi Aiso
  • Patent number: 8188558
    Abstract: In order to increase an efficiency of spin transfer and thereby reduce the required switching current, a current perpendicular to plane (CPP) magnetic element for a memory device includes either one or both of a free magnetic layer, which has an electronically reflective surface, and a permanent magnet layer, which has perpendicular anisotropy to bias the free magnetic layer.
    Type: Grant
    Filed: June 27, 2011
    Date of Patent: May 29, 2012
    Assignee: Seagate Technology LLC
    Inventors: Dexin Wang, Dimitar V. Dimitrov, Song S. Xue, Insik Jin
  • Publication number: 20120049303
    Abstract: A semiconductor device includes a Hall element, which is switched between a first and second mode. In the first mode, connection A between a first and second resistor and connection C between a third and fourth resistor are set to Vcc or GND. Connection D between the first and fourth resistor and connection B between the second and third resistor are set as output terminals. In the second mode, D and B are set to Vcc or GND and A and C are set as output terminals. When a first line placed along the second resistor and connected to A is set at Vcc in the first mode, a second line placed along the fourth resistor and connected to D is set at Vcc in the second mode. When the first line is set at GND in first mode, the second line is set at GND in the second mode.
    Type: Application
    Filed: August 23, 2011
    Publication date: March 1, 2012
    Applicant: ON SEMICONDUCTOR TRADING, LTD.
    Inventors: Takashi Ogawa, Hironori Terazawa, Akihiro Hasegawa, Takashi Naruse, Yuuhei Mouri
  • Patent number: 7999360
    Abstract: An MRAM structure is disclosed in which the bottom electrode has an amorphous TaN capping layer to consistently provide smooth and dense growth for AFM, pinned, tunnel barrier, and free layers in an overlying MTJ. Unlike a conventional Ta capping layer, TaN is oxidation resistant and has high resistivity to avoid shunting of a sense current caused by redeposition of the capping layer on the sidewalls of the tunnel barrier layer. Alternatively, the ?-TaN layer is the seed layer in the MTJ. Furthermore, the seed layer may be a composite layer of NiCr, NiFe, or NiFeCr layer on the oc-TaN layer. An ?-TaN capping layer or seed layer can also be used in a TMR read head. An MTJ formed on an ?-TaN capping layer has a high MR ratio, high Vb, and a RA similar to results obtained from MTJs based on an optimized Ta capping layer.
    Type: Grant
    Filed: October 23, 2009
    Date of Patent: August 16, 2011
    Assignees: Headway Technologies, Inc., MagIC Technologies, Inc.
    Inventors: Liubo Hong, Cheng Horng, Mao-Min Chen, Ru-Yin Tong
  • Patent number: 7999336
    Abstract: In order to increase an efficiency of spin transfer and thereby reduce the required switching current, a current perpendicular to plane (CPP) magnetic element for a memory device includes either one or both of a free magnetic layer, which has an electronically reflective surface, and a permanent magnet layer, which has perpendicular anisotropy to bias the free magnetic layer.
    Type: Grant
    Filed: April 24, 2008
    Date of Patent: August 16, 2011
    Assignee: Seagate Technology LLC
    Inventors: Dexin Wang, Dimitar V. Dimitrov, Song S. Xue, Insik Jin
  • Patent number: 7973351
    Abstract: A stack includes a crystalline MgO layer, crystalline Heusler alloy layer, and amorphous Heusler alloy layer. The crystalline Heusler alloy layer is provided on the MgO layer. The amorphous Heusler alloy layer is provided on the crystalline Heusler alloy layer.
    Type: Grant
    Filed: September 23, 2009
    Date of Patent: July 5, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Takao Marukame, Mizue Ishikawa, Tomoaki Inokuchi, Hideyuki Sugiyama, Yoshiaki Saito
  • Patent number: 7936030
    Abstract: Provided are a multi-purpose magnetic film structure using a spin charge, a method of manufacturing the same, a semiconductor device having the same, and a method of operating the semiconductor memory device. The multi-purpose magnetic film structure includes a lower magnetic film, a tunneling film formed on the lower magnetic film, and an upper magnetic film formed on the tunneling film, wherein the lower and upper magnetic films are ferromagnetic films forming an electrochemical potential difference therebetween when the lower and upper magnetic films have opposite magnetization directions.
    Type: Grant
    Filed: August 30, 2010
    Date of Patent: May 3, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Tae-wan Kim, Wan-jun Park, Sang-jin Park, In-jun Hwang, Soon-ju Kwon, Young-keun Kim, Richard J. Gambino
  • Publication number: 20110090732
    Abstract: A particular magnetic tunnel junction (MTJ) cell includes a side wall defining a first magnetic domain adapted to store a first digital value. The MTJ cell also includes a bottom wall coupled to the side wall and defining a second magnetic domain adapted to store a second digital value.
    Type: Application
    Filed: December 21, 2010
    Publication date: April 21, 2011
    Applicant: QUALCOMM INCORPORATED
    Inventors: Xia Li, Seung H. Kang, Xiaochun Zhu
  • Publication number: 20110049655
    Abstract: A semiconductor device includes a substrate including an M2 patterned area. A VA pillar structure is formed over the M2 patterned area. The VA pillar structure includes a substractively patterned metal layer. The VA pillar structure is a sub-lithographic contact. An MTJ stack is formed over the oxide layer and the metal layer of the VA pillar. A size of the MTJ stack and a shape anisotropy of the MTJ stack are independent of a size and a shape anisotropy of the sub-lithographic contact.
    Type: Application
    Filed: August 28, 2009
    Publication date: March 3, 2011
    Applicant: International Business Machines Corporation
    Inventors: Solomon Assefa, Michael C. Gaidis, Eric A. Joseph, Eugene J. O'Sullivan
  • Patent number: 7867788
    Abstract: A Spin-Dependent Tunnelling cell comprises a first barrier layer of a first material and a second barrier layer of a second material sandwiched between a first ferromagnetic layer and a second ferromagnetic layer. The first and second barrier layers are formed to a combined thicknesses so that a Tunnelling Magnetoresistance versus voltage characteristic of the cell has a maximum at a non-zero bias voltage.
    Type: Grant
    Filed: September 20, 2005
    Date of Patent: January 11, 2011
    Assignees: Freescale Semiconductor, Inc., Centre National de la Recherché Scientifique (CNRS), STMicroelectronics (Crolles 2) SAS
    Inventors: De Come Buttet, Michel Hehn, Stephane Zoll
  • Patent number: 7851840
    Abstract: Devices having magnetic or magnetoresistive tunnel junctions (MTJS) have a multilayer insulator barrier layer to produce balanced write switching currents in the device circuitry, or to produce the magnetic devices with balanced critical spin currents required for spin torque transfer induced switching of the magnetization, or both for the MTJs under both the forward and reversed bias directions.
    Type: Grant
    Filed: September 13, 2006
    Date of Patent: December 14, 2010
    Assignee: Grandis Inc.
    Inventors: Zhitao Diao, Yiming Huai
  • Patent number: 7848136
    Abstract: It is possible to reduce writing current without causing fluctuation of the writing characteristic. A magnetic memory includes: a magnetoresistance effect element having a magnetization pinned layer whose magnetization direction is pinned, a storage layer whose magnetization direction is changeable, and a non-magnetic layer provided between the magnetization pinned layer and the storage layer; and a first wiring layer which is electrically connected to the magnetoresistance effect element and extends in a direction substantially perpendicular to a direction of an easy magnetization axis of the storage layer, an end face of the magnetoresistance effect element substantially perpendicular to the direction of the easy magnetization axis of the storage layer and an end face of the first wiring layer substantially perpendicular to the direction of the easy magnetization axis being positioned on the same plane.
    Type: Grant
    Filed: April 10, 2008
    Date of Patent: December 7, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hisanori Aikawa, Tomomasa Ueda, Tatsuya Kishi, Takeshi Kajiyama, Yoshiaki Asao, Hiroaki Yoda
  • Patent number: 7833806
    Abstract: A method of forming a magnetoelectronic device includes forming a dielectric material (114) surrounding a magnetic bit (112), etching the dielectric material (114) to define an opening (122) over the magnetic bit (112) without exposing the magnetic bit (112), the opening (122) having a sidewall, depositing a blanket layer (132) of cladding material over the dielectric material (118), including over the sidewall, removing by a sputtering process the blanket layer (132) in the bottom of the opening (122) and the dielectric material (124) over the magnetic bit (112), and forming a conductive material (146) within the opening (122) to form a bit line (154). This process reduces errors caused by process irregularities such as edges of the bits (112) protruding and thereby causing defects in the cladding layer (132) formed thereover.
    Type: Grant
    Filed: January 30, 2009
    Date of Patent: November 16, 2010
    Assignee: Everspin Technologies, Inc.
    Inventors: Kenneth H. Smith, Nicholas D. Rizzo, Sanjeev Aggarwal, Anthony Ciancio, Brian R. Butcher, Kelly Wayne Kyler
  • Patent number: 7825486
    Abstract: A programmable magnetoresistive memory cell. The memory cell has a magnetic element that includes a first and a second ferromagnetic layer. The first and second ferromagnetic layers are separated by a non-ferromagnetic and preferably electrically insulating spacer layer. The data bit is read out by measuring the electrical resistance across the magnetic element. The memory cell further includes: a third ferromagnetic layer having a well-defined magnetization direction and a resistance switching material having a carrier density. The carrier density can be altered by causing an ion concentration to become altered by means of an applied electrical voltage signal. Thus, the carrier density can be switched between a first and second state.
    Type: Grant
    Filed: January 14, 2009
    Date of Patent: November 2, 2010
    Assignee: International Business Machines Corporation
    Inventors: Siegfried Friedrich Karg, Gerhard Ingmar Meijer
  • Patent number: 7821088
    Abstract: A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, nonmagnetic spacer, and free layers. The spacer layer resides between the pinned and free layers. The free layer can be switched using spin transfer when a write current is passed through the magnetic element. The free layer includes a first ferromagnetic layer and a second ferromagnetic layer. The second ferromagnetic layer has a very high perpendicular anisotropy and an out-of-plane demagnetization energy. The very high perpendicular anisotropy energy is greater than the out-of-plane demagnetization energy of the second layer.
    Type: Grant
    Filed: June 5, 2008
    Date of Patent: October 26, 2010
    Assignee: Grandis, Inc.
    Inventors: Paul P. Nguyen, Yiming Huai
  • Patent number: 7820455
    Abstract: A method for manufacturing a magnetoresistive sensor that provides increased magnetoresistive performance. The method includes forming a series of sensor layers with at least one layer containing CoFeB, and having a first capping layer thereover. A high temperature annealing is performed to optimize the grains structure of the sensor layers. The first capping layer is then removed, such as by reactive ion etching (RIE). An antiferromagnetic layer is then deposited followed by a second capping layer. A second annealing is performed to set the magnetization of the pinned layer, the second annealing being performed at a lower temperature than the first annealing.
    Type: Grant
    Filed: March 31, 2008
    Date of Patent: October 26, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hardayal Singh Gill, Wipul Pemsiri Jayasekara
  • Patent number: 7816746
    Abstract: A spin-tunnel transistor having a tunnel barrier layer formed of an antiferromagnetic material which is exchange coupled with a first or second ferromagnetic metal layer of a base B formed adjoining to the antiferromagnetic material, so as to fix magnetization of the adjoining ferromagnetic layer. The base B includes a nonmagnetic metal layer which is formed between the first and second ferromagnetic metal layers and decouple magnetization coupling between the first and second ferromagnetic metal layers. The base B is formed between a collector and an emitter to form tri-terminal device. Those spin-tunnel transistor may be used as a sensor of a magnetic reproducing head used in a hard disk drive.
    Type: Grant
    Filed: September 24, 2003
    Date of Patent: October 19, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Rie Sato, Koichi Mizushima
  • Patent number: 7811833
    Abstract: Provided are a multi-purpose magnetic film structure using a spin charge, a method of manufacturing the same, a semiconductor device having the same, and a method of operating the semiconductor memory device. The multi-purpose magnetic film structure includes a lower magnetic film, a tunneling film formed on the lower magnetic film, and an upper magnetic film formed on the tunneling film, wherein the lower and upper magnetic films are ferromagnetic films forming an electrochemical potential difference therebetween when the lower and upper magnetic films have opposite magnetization directions.
    Type: Grant
    Filed: September 14, 2007
    Date of Patent: October 12, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Tae-wan Kim, Wan-jun Park, Sang-jin Park, In-jun Hwang, Soon-ju Kwon, Young-keun Kim, Richard J. Gambino
  • Publication number: 20100244163
    Abstract: A magnetoresistive element includes a stabilization layer, a nonmagnetic layer, a spin-polarization layer provided between the stabilization layer and the nonmagnetic layer, the spin-polarization layer having magnetic anisotropy in a perpendicular direction, and a magnetic layer provided on a side of the nonmagnetic layer opposite to a side on which the spin-polarization layer is provided. The stabilization layer has a lattice constant smaller than that of the spin-polarization layer in an in-plane direction. The spin-polarization layer contains at least one element selected from a group consisting of cobalt (Co) and iron (Fe), has a body-centered tetragonal (BCT) structure, and has a lattice constant ratio c/a of 1.10 (inclusive) to 1.35 (inclusive) when a perpendicular direction is a c-axis and an in-plane direction is an a-axis.
    Type: Application
    Filed: March 3, 2010
    Publication date: September 30, 2010
    Inventors: Tadaomi Daibou, Toshihiko Nagase, Eiji Kitagawa, Masatoshi Yoshikawa, Katsuya Nishiyama, Makoto Nagamine, Tatsuya Kishi, Hiroaki Yoda
  • Patent number: 7781816
    Abstract: A nonvolatile magnetic memory device including a magnetoresistance device having a recording layer formed of a ferromagnetic material for storing information by use of variation in resistance depending on the magnetization inversion state. The plan-view shape of the recording layer includes a pseudo-rhombic shape having four sides, at least two of the four sides each include a smooth curve having a central portion curved toward the center of the pseudo-rhombic shape. The easy axis of magnetization of the recording layer is substantially parallel to the longer axis of the pseudo-rhombic shape. The hard axis of magnetization of the recording layer is substantially parallel to the shorter axis of the pseudo-rhombic shape. The sides constituting the plan-view shape of the recording layer are smoothly connected to each other.
    Type: Grant
    Filed: June 16, 2008
    Date of Patent: August 24, 2010
    Assignee: Sony Corporation
    Inventor: Hajime Yamagishi
  • Patent number: 7772659
    Abstract: The magnetic device comprises a least two layers made of a magnetic material that are separated by at least one interlayer made of a non-magnetic material. The layers made of a magnetic material each have magnetization oriented substantially perpendicular to the plane of the layers. The layer of non-magnetic material induces an antiferromagnetic coupling field between the layers made of a magnetic material, the direction and amplitude of this field attenuating the effects of the ferromagnetic coupling field of magnetostatic origin that occurs between the magnetic layers.
    Type: Grant
    Filed: October 22, 2007
    Date of Patent: August 10, 2010
    Assignees: Commissariat a l'Energie Atomique, Centre National de la Recherche Scientifique
    Inventors: Bernard Rodmacq, Vincent Baltz, Alberto Bollero, Bernard Dieny
  • Patent number: 7772663
    Abstract: In one embodiment, the invention is a method and apparatus for bitline and contact via integration in magnetic random access memory arrays. One embodiment of a magnetic random access memory according to the present invention includes a magnetic tunnel junction and a top wire that surrounds the magnetic tunnel junction on at least three sides.
    Type: Grant
    Filed: February 21, 2007
    Date of Patent: August 10, 2010
    Assignee: International Business Machines Corporation
    Inventors: Sivananda Kanakasabapathy, Michael C. Gaidis
  • Patent number: 7772679
    Abstract: This invention provides a magnetic shielding package structure of a magnetic memory device, in which at least a magnetic memory device is embedded between a magnetic shielding substrate and a magnetic shielding layer. A plurality of through vias is formed in the magnetic shielding substrate or the magnetic shielding layer, and a plurality of conductive contacts passes through the through vias such that electrical connection between the magnetic memory device and the external is established.
    Type: Grant
    Filed: June 23, 2008
    Date of Patent: August 10, 2010
    Assignee: Industrial Technology Research Institute
    Inventors: Shu-Ming Chang, Ying-Ching Shih
  • Publication number: 20100176429
    Abstract: An MRAM is disclosed that has a MTJ comprised of a ferromagnetic layer with a magnetization direction along a first axis, a super-paramagnetic (SP) free layer, and an insulating layer formed therebetween. The SP free layer has a remnant magnetization that is substantially zero in the absence of an external field, and in which magnetization is roughly proportional to an external field until reaching a saturation value. In one embodiment, a separate storage layer is formed above, below, or adjacent to the MTJ and has uniaxial anisotropy with a magnetization direction along its easy axis which parallels the first axis. In a second embodiment, the storage layer is formed on a non-magnetic conducting spacer layer within the MTJ and is patterned simultaneously with the MTJ. The SP free layer may be multiple layers or laminated layers of CoFeB. The storage layer may have a SyAP configuration and a laminated structure.
    Type: Application
    Filed: March 16, 2010
    Publication date: July 15, 2010
    Inventors: Po-Kang Wang, Yimin Guo, Cheng T. Horng, Tai Min, Ru-Ying Tong
  • Patent number: 7745893
    Abstract: A magnetic transistor includes a first magnetic section, a second magnetic section, a conductive section, a first metal terminal, and a second metal terminal. The conductive section is disposed between and is in direct contact with both the first and second magnetic section. The first metal terminal is disposed on one end of an opposite surface to the conductive section of the first magnetic section. The second metal terminal is disposed on one end approximately diagonal to the first metal terminal on an opposite surface to the conductive section of the second magnetic section. While the magnetic transistor structure is turned on, a current flows through the first magnetic section and the second magnetic section via the conductive section.
    Type: Grant
    Filed: October 6, 2006
    Date of Patent: June 29, 2010
    Assignee: Northern Lights Semiconductor Corp.
    Inventors: James Chyi Lai, Tom Allen Agan
  • Publication number: 20100135067
    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: Application
    Filed: December 2, 2008
    Publication date: June 3, 2010
    Applicant: Seagate Technology LLC
    Inventors: Dimitar V. Dimitrov, Olle Gunnar Heinonen, Dexin Wang, Haiwen Xi
  • Patent number: 7727409
    Abstract: A method of production of a magnetoresistance effect device is able to prevent or minimize a drop in the MR ratio and maintain the high performance of the magnetoresistance effect device even if forming an oxide layer as a surface-most layer constituting a protective layer by the oxidation process inevitably included in the process of production of microprocessing by dry etching performed in a vacuum. Two mask layers used for microprocessing are doubly piled up. This method of production of a magnetoresistivity effect device including a magnetic multilayer film including at least two magnetic layers includes a step of providing under a first mask material that is a nonorganic material a second mask material able to react with other atoms to form a conductive substance, and a device made according to the method.
    Type: Grant
    Filed: May 9, 2008
    Date of Patent: June 1, 2010
    Assignee: Canon Anelva Corporation
    Inventors: Hiroki Maehara, Tomoaki Osada, Mihoko Doi, Koji Tsunekawa, Naoki Watanabe
  • Publication number: 20100123208
    Abstract: A magneto-resistive device having a large output signal as well as a high signal-to-noise ratio is described along with a process for forming it. This improved performance was accomplished by expanding the free layer into a multilayer laminate comprising at least three ferromagnetic layers separated from one another by antiparallel coupling layers. The ferromagnetic layer closest to the transition layer must include CoFeB while the furthermost layer is required to have low Hc as well as a low and negative lambda value. One possibility for the central ferromagnetic layer is NiFe but this is not mandatory.
    Type: Application
    Filed: November 19, 2008
    Publication date: May 20, 2010
    Inventors: Tong Zhao, Hui-Chuan Wang, Yu-Chen Zhou, Min Li, Kunliang Zhang
  • Publication number: 20100003834
    Abstract: Disclosed is a method to convert a low resistance cell in a MRAM device to a capacitive cell. The low resistance cell has a plurality of layers on a substrate. At least one layer remote from the substrate is sensitive to oxygen infusion. The method includes removing a cap layer of the cell and applying an oxygen barrier around the cell to expose at least a part of a surface of the at least one layer remote from the substrate. The at least one layer is oxidized. The oxygen barrier is removed.
    Type: Application
    Filed: June 29, 2009
    Publication date: January 7, 2010
    Applicant: Showa Denko HD Singapore Pte Ltd
    Inventor: Kor Seng ANG
  • Publication number: 20090315128
    Abstract: The semiconductor device which has a memory cell including the TMR film with which memory accuracy does not deteriorate, and its manufacturing method are obtained. A TMR element (a TMR film, a TMR upper electrode) is selectively formed in the region which corresponds in plan view on a TMR lower electrode in a part of formation area of a digit line. A TMR upper electrode is formed by 30-100 nm thickness of Ta, and functions also as a hard mask at the time of a manufacturing process. The interlayer insulation film formed from LT-SiN on the whole surface of a TMR element and the upper surface of a TMR lower electrode is formed, and the interlayer insulation film which covers the whole surface comprising the side surface of a TMR lower electrode, and includes LT-SiN is formed. The interlayer insulation film which covers the whole surface and includes SiO2 is formed.
    Type: Application
    Filed: August 28, 2009
    Publication date: December 24, 2009
    Inventors: Haruo Furuta, Ryoji Matsuda, Shuichi Ueno, Takeharu Kuroiwa
  • Patent number: 7635903
    Abstract: An oscillator includes at least one of: (i) a parallel array of resistors (420, 421, 422, 701, 801, 901, 902) or magnetoresistive contacts to a magnetoresistive film (120, 320); and (ii) a series array of resistors (620, 621, 702, 902) or magnetoresistive contacts to individualized areas of at least one magnetoresistive film.
    Type: Grant
    Filed: September 13, 2005
    Date of Patent: December 22, 2009
    Assignee: Everspin Technologies, Inc.
    Inventors: Frederick B. Mancoff, Bradley N. Engel, Nicholas D. Rizzo
  • Publication number: 20090224300
    Abstract: A nonvolatile magnetic memory device includes a magnetoresistance effect element that includes: a layered structure having a recording layer; a first wiring electrically connected to a lower part of the layered structure; a second wiring electrically connected to an upper part of the layered structure; and an interlayer insulation layer surrounding the layered structure. The magnetoresistance effect element further includes a low Young modulus region having a Young modulus lower than that of a material forming the interlayer insulation layer. The recording layer has an easy magnetization axis, and a hard magnetization axis orthogonal to the easy magnetization axis. When the magnetostriction constant ? of a material forming the recording layer is a positive value or a negative value, the low Young modulus region is disposed in an extension region of the easy magnetization axis or in an extension region of the hard magnetization axis of the recording layer, respectively.
    Type: Application
    Filed: March 2, 2009
    Publication date: September 10, 2009
    Applicant: Sony Corporation
    Inventors: Hajime Yamagishi, Shoji Ichikawa, Takashi Kinoshita, Masanori Hosomi, MItsuharu Shoji
  • Publication number: 20090219754
    Abstract: A magnetic film stack is composed of a synthetic antiferromagnet including a plurality of ferromagnetic layers, adjacent two of which are antiferromagnetically coupled through a non-magnetic layer; and a reversal inducing layer exhibiting ferromagnetism. The reversal inducing layer is ferromagnetically coupled to the synthetic antiferromagnet, and designed to have a coercive field smaller than a magnetic field at which antiferromagnetic coupling within the synthetic antiferromagnet starts to be decoupled.
    Type: Application
    Filed: May 1, 2009
    Publication date: September 3, 2009
    Inventor: Yoshiyuki Fukumoto
  • Publication number: 20090206426
    Abstract: A magnetoresistive element includes first, second, and third fixed layers, first, second, and third spacer layers, and a free layer. The first fixed layer is made of a ferromagnetic material and having an invariable magnetization direction. The first spacer layer is formed on the first fixed layer and made of an insulator. The free layer is formed on the first spacer layer, made of a ferromagnetic material, and having a variable magnetization direction. The second spacer layer is formed on the free layer and made of a nonmagnetic material. The second fixed layer is formed on the second spacer layer, made of a ferromagnetic material, and having an invariable magnetization direction. The third spacer layer is formed below the first fixed layer and made of a nonmagnetic material. The third fixed layer is formed below the third spacer layer, made of a ferromagnetic material, and having an invariable magnetization direction.
    Type: Application
    Filed: February 11, 2009
    Publication date: August 20, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Takeshi KAJIYAMA
  • Patent number: 7564110
    Abstract: Tunneling magnetoresistive (TMR) electrical lapping guides (ELG) are disclosed for use in wafer fabrication of magnetic sensing devices, such as magnetic recording heads using TMR read elements. A TMR ELG includes a TMR stack comprising a first conductive layer, a barrier layer, and a second conductive layer of TMR material. The TMR ELG also includes a first lead and a second lead that connect to conductive pads used for applying a sense current to the TMR ELG in a current in plane (CIP) fashion. The first lead contacts one side of the TMR stack so that the first lead contacts both the first conductive layer and the second conductive layer of the TMR stack. The second lead contacts the other side of the TMR stack so that the second lead contacts both the first conductive layer and the second conductive layer of the TMR stack.
    Type: Grant
    Filed: April 19, 2006
    Date of Patent: July 21, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Robert S. Beach, Daniele Mauri, David J. Seagle, Jila Tabib
  • Publication number: 20090180311
    Abstract: The present invention provides a novel element capable of simply controlling an in-plane rotational motion of a core (a rising spot of a magnetization) generated in the center of a ferromagnetic dot made by forming a ferromagnetic material into a nanosized disk shape. In addition, the present invention is achieved to provide a binary information memory element using a core, including a ferromagnetic dot, made of a disk-shaped ferromagnetic material, with a magnetic structure of a magnetic vortex structure, and a current supplier for supplying an alternating current with a predetermined alternating current in the radial direction of the ferromagnetic dot. In the case where the frequency of the current resonates with the intrinsic frequency of the ferromagnetic dot, it is possible to rotate the core in the plane of the dot. Since the core leaks a magnetic field, a microscopic actuator such as a motor can be obtained by using this element.
    Type: Application
    Filed: March 1, 2007
    Publication date: July 16, 2009
    Applicants: Kyoto University, The University of Electro-Communications, Osaka University, Tokyo Metropolitan University
    Inventors: Teruo Ono, Shinya Kasai, Kensuke Kobayashi, Yoshinobu Nakatani, Hiroshi Kohno, Gen Tatara
  • Publication number: 20090168502
    Abstract: There is provided a semiconductor device that enables high-speed data read and reduces the area of a drive circuit for activating a word line. By signal transmission through a common word line having a low resistance and coupled at a plurality of points to a word line, it is possible to read data at high speed. Further, since the common word line is provided common to a plurality of memory blocks, a word line driver can be provided common to the memory blocks. Further, by disposing a latch circuit, corresponding to a sub-digit line, for holding the active state of the common word line, it is possible to transmit a row selection signal during data write through the common word line and thereby reduce a metal wiring layer.
    Type: Application
    Filed: December 19, 2008
    Publication date: July 2, 2009
    Inventors: Shota Okayama, Yasumitsu Murai
  • Publication number: 20090146232
    Abstract: A magnetoresistive device comprises a ferromagnetic region, a non-ferromagnetic region, an insulating region and a conductive region. The insulating region is arranged between the ferromagnetic region and the conductive region so as to provide a tunnel barrier. The non-ferromagnetic region separates the insulating region and the ferromagnetic region.
    Type: Application
    Filed: November 26, 2008
    Publication date: June 11, 2009
    Inventors: Joerg Wunderlich, Byong Guk Park, Alexander Shick, Tomas Jungwirth, Frantisek Maca
  • Publication number: 20090140358
    Abstract: A magnetoresistive element includes a first ferromagnetic layer having a first magnetization, the first magnetization having a first pattern when the magnetoresistive element is half-selected during a first data write, a second pattern when the magnetoresistive element is selected during a second data write, and a third pattern of residual magnetization, the first pattern being different from the second and third pattern, a second ferromagnetic layer having a second magnetization, and a nonmagnetic layer arranged between the first ferromagnetic layer and the second ferromagnetic layer and having a tunnel conductance changing dependent on a relative angle between the first magnetization and the second magnetization.
    Type: Application
    Filed: February 2, 2009
    Publication date: June 4, 2009
    Inventors: Masahiko Nakayama, Tadashi Kai, Tatsuya Kishi, Yoshiaki Fukuzumi, Toshihiko Nagase, Sumio Ikegawa, Hiroaki Yoda
  • Patent number: 7542335
    Abstract: It is a task to provide a magnetic storage device of complementary type, of which reliability is improved by precisely performing writing storage data. In the present invention, therefore, in a magnetic storage device of complementary type for storing storage data contrary to each other in a first ferromagnetic tunnel junction element and a second ferromagnetic tunnel junction element, respectively, the first ferromagnetic tunnel junction element and the second ferromagnetic tunnel junction element are formed adjacently on a semiconductor substrate, first writing lines is wound around the first ferromagnetic tunnel junction element like a coil and the same time second writing lines is wound around the second ferromagnetic tunnel junction element like a coil, and in addition, a winding direction of the first writing lines and a winding direction of the second writing lines are reversed to each other.
    Type: Grant
    Filed: September 18, 2003
    Date of Patent: June 2, 2009
    Assignee: Sony Corporation
    Inventors: Hiroshi Yoshihara, Katsutoshi Moriyama, Hironobu Mori, Nobumichi Okazaki
  • Patent number: 7538402
    Abstract: A magnetic film stack is composed of a synthetic antiferromagnet including a plurality of ferromagnetic layers, adjacent two of which are antiferromagnetically coupled through a non-magnetic layer; and a reversal inducing layer exhibiting ferromagnetism. The reversal inducing layer is ferromagnetically coupled to the synthetic antiferromagnet, and designed to have a coercive field smaller than a magnetic field at which antiferromagnetic coupling within the synthetic antiferromagnet starts to be decoupled.
    Type: Grant
    Filed: May 18, 2006
    Date of Patent: May 26, 2009
    Assignee: NEC Corporation
    Inventor: Yoshiyuki Fukumoto
  • Patent number: 7531823
    Abstract: An electronic device includes at least a memory core formed of an alloy serving as an electronic conductor and an electrode provided on each of both ends of the memory core. Data is written on the electronic device by supplying an electric current to allow the alloy composition to be biased. The memory core is formed of an alloy which is in a crystallographically stable state before writing or at the time of data recording and in which a non-equilibrium state accompanying with a solid-solid phase transition can be achieved during temperature increase. In this case, the electronic device operates at a very fast speed by utilizing a metastable state and electromigration which takes place at a very fast rate in a non-equilibrium state during a phase transition, thereby ensuring stable writing or re-writing operation.
    Type: Grant
    Filed: January 23, 2004
    Date of Patent: May 12, 2009
    Assignee: NEC Corporation
    Inventor: Akio Tanikawa
  • Patent number: 7531882
    Abstract: A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, nonmagnetic spacer, and free layers. The spacer layer resides between the pinned and free layers. The free layer can be switched using spin transfer when a write current is passed through the magnetic element. The magnetic element may also include a barrier layer, a second pinned layer. Alternatively, second pinned and second spacer layers and a second free layer magnetostatically coupled to the free layer are included. At least one free layer has a high perpendicular anisotropy. The high perpendicular anisotropy has a perpendicular anisotropy energy that is at least twenty and less than one hundred percent of the out-of-plane demagnetization energy.
    Type: Grant
    Filed: September 30, 2005
    Date of Patent: May 12, 2009
    Assignee: Grandis, Inc.
    Inventors: Paul P. Nguyen, Yiming Huai
  • Publication number: 20090096043
    Abstract: We describe the manufacturing process for and structure of a CPP MTJ MRAM unit cell that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The strength of the switching field, Hs of the cell is controlled by the magnetic anisotropy of the cell which, in turn, is controlled by a combination of the shape anisotropy and the stress and magnetostriction of the cell free layer. The coefficient of magnetostriction of the free layer can be adjusted by methods such as adding Nb or Hf to alloys of Ni, Fe, Co and B or by forming the free layer as a lamination of layers having different values of their coefficients of magnetostriction. Thus, by tuning the coefficient of magnetostriction of the cell free layer it is possible to produce a switching field of sufficient magnitude to render the cell thermally stable while maintaining a desirable switching current.
    Type: Application
    Filed: October 10, 2007
    Publication date: April 16, 2009
    Inventors: Tai Min, Po Kang Wang
  • Patent number: 7473951
    Abstract: A magnetic random access memory (MRAM), and a method of manufacturing the same, includes a cell including a transistor and a magnetic tunneling junction (MTJ) layer connected to the transistor, wherein the MTJ layer includes a lower electrode, a lower magnetic film, a tunneling film having a uniform thickness and a substantially flat upper surface, and an upper magnetic film, wherein the lower electrode includes a first lower electrode and an amorphous second lower electrode. An amorphous flattening film may be further formed between the lower electrode and the lower magnetic film.
    Type: Grant
    Filed: September 24, 2004
    Date of Patent: January 6, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Tae-wan Kim, Sang-jin Park
  • Publication number: 20080309331
    Abstract: A giant magnetoresistive sensor apparatus is described that provides improved multilayer quality, hysteresis, linearity and sensitivity. The multilayer structure includes NiFeCr as buffer and cap layers. The sensing resistor is designed in the form of a serpentine structure. To minimize the hysteresis and improve the linearity, the resistor end is tapered and elongated. In forming the sensor in a Wheatstone bridge configuration, two resistors are shielded by thick NiFe layers, while the two sensing resistors are not shielded and open to external signal fields. The shields can not only shield the influence of the external field on the shielded resistors but also serve as magnetic flux concentrators to magnify the external field on the unshielded resistors. The bridge output reflects the resistance change of the two unshielded sensing resistors.
    Type: Application
    Filed: June 15, 2007
    Publication date: December 18, 2008
    Inventors: Zhenghong Qian, Gunther Baubock, Barry T. O'Connell
  • Publication number: 20080308885
    Abstract: A magnetic random access memory including a substrate, a first conductor layer, a magnetic layer, an insulating layer, a dielectric layer, two contacts and a second conductor layer is provided. The first conductor layer is disposed on the substrate. The magnetic layer is disposed on the first conductor layer. The insulating layer is disposed between the first conductor layer and the magnetic layer, and the thickness of the insulating layer is less than or equal to 1000 angstroms. The dielectric layer is disposed on the substrate and covers the magnetic layer, the insulating layer and the first conductor layer. The contacts are disposed in the dielectric layer and electrically connected to the first conductor layer and the magnetic layer respectively. The second conductor layer is disposed on the dielectric layer and includes two conductor patterns electrically connected to the corresponding contacts respectively.
    Type: Application
    Filed: June 12, 2007
    Publication date: December 18, 2008
    Applicant: UNITED MICROELECTRONICS CORP.
    Inventor: Chao-Hung Lu
  • Patent number: 7456082
    Abstract: In a method for producing a silicon single by pulling the silicon single crystal from a silicon melt contained in a crucible, a magnetic field is applied to the silicon melt in a radial direction of the silicon single crystal, and a vertical level of a center of the magnetic field relative to a surface of the silicon melt is controlled such that a thermal gradient in an axial direction of the crystal is maintained at a constant value in respective portions along a radial direction of the silicon single crystal.
    Type: Grant
    Filed: July 24, 2006
    Date of Patent: November 25, 2008
    Assignee: Sumco Corporation
    Inventor: Keisei Abe
  • Patent number: 7453084
    Abstract: A transistor has an emitter, a spin-selective base, a collector, a first barrier interposed between the spin-selective base and the emitter, a second barrier interposed between the spin-selective base and the collector, and a transfer ratio of more than 10?3.
    Type: Grant
    Filed: May 24, 2005
    Date of Patent: November 18, 2008
    Assignee: Seagate Technology LLC
    Inventors: Janusz J. Nowak, Brian W. Karr, David H. Olson, Eric S. Linville, Paul E. Anderson