Magnetoresistive Patents (Class 428/811)
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Patent number: 11133459Abstract: According to one embodiment, a magnetic element includes a first layer and a second layer. The first layer includes a first element and a second element. The first element includes at least one selected from the group consisting of Fe, Co, and Ni. The second element includes at least one selected from the group consisting of Ir and Os. The second layer is nonmagnetic.Type: GrantFiled: February 15, 2018Date of Patent: September 28, 2021Assignees: National Institute of Advanced Industrial Science and Technology, TOHOKU UNIVERSITY, NATIONAL INSTITUTE FOR MATERIALS SCIENCEInventors: Takayuki Nozaki, Shinji Yuasa, Rachwal Anna Koziol, Masahito Tsujikawa, Masafumi Shirai, Kazuhiro Hono, Tadakatsu Ohkubo, Xiandong Xu
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Patent number: 11072842Abstract: Provided is a rare earth thin film magnet having Nd, Fe and B as essential components, which is characterized in that a Nd—Fe—B base film is formed on a Si substrate having an oxide film formed on a surface thereof and has a composition in which the Nd content is higher than that of a stoichiometric composition and that a film (nano composite film) is formed on the base film and has a texture in which an ?-Fe phase and Nd2Fe14B are alternately arranged and three-dimensionally dispersed. The rare earth thin film magnet provided is less susceptible to the occurrence of film separation and substrate breakage and exhibits favorable magnetic properties.Type: GrantFiled: March 29, 2017Date of Patent: July 27, 2021Assignee: JX NIPPON MINING & METALS CORPORATIONInventors: Masaki Nakano, Hirotoshi Fukunaga, Takeshi Yanai, Hironobu Sawatari
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Patent number: 11005029Abstract: A device is disclosed. The device includes a first magnetic layer and a tunnel barrier. The first magnetic layer has a volume uniaxial magnetic crystalline anisotropy. The magnetic moment of the first layer is substantially perpendicular to the first layer. The tunnel barrier is in proximity to the first magnetic layer. The orientation of the magnetic moment of the first magnetic layer is reversed by spin transfer torque induced by current passing between and through the first magnetic layer and the tunnel barrier.Type: GrantFiled: September 28, 2018Date of Patent: May 11, 2021Assignees: Samsung Electronics Co., Ltd.Inventors: Jaewoo Jeong, Mahesh G. Samant, Stuart S. P. Parkin, Yari Ferrante
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Patent number: 10971360Abstract: A transistor comprises channel material having first and second opposing sides. A gate is on the first side of the channel material and a gate insulator is between the gate and the channel material. A first insulating material has first and second opposing sides, with the first side being adjacent the second side of the channel material. A second insulating material of different composition from that of the first insulating material is adjacent the second side of the first insulating material. The second insulating material has at least one of (a), (b), and (c), where, (a): lower oxygen diffusivity than the first material, (b): net positive charge, and (c): at least two times greater shear strength than the first material. In some embodiments, an array of elevationally-extending strings of memory cells comprises such transistors. Other embodiments, including method, are disclosed.Type: GrantFiled: September 25, 2019Date of Patent: April 6, 2021Assignee: Micron Technology, Inc.Inventors: David H. Wells, Anish A. Khandekar, Kunal Shrotri, Jie Li
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Patent number: 10923150Abstract: The purpose of the present invention is to provide a magnetic recording medium having a stacked structure of a seed layer including (Mg1-xTix)O and a magnetic recording layer including an L10 ordered alloy, and having improved properties. The method for producing a magnetic recording layer according to the present invention includes the steps of: (1) preparing a substrate; (2) forming a seed layer including (Mg1-xTix)O onto the substrate; (3) plasma etching the seed layer in an atmosphere including inert gas; and (4) forming a magnetic recording layer including an ordered alloy onto the seed layer which has been subjected to the step (3).Type: GrantFiled: October 2, 2017Date of Patent: February 16, 2021Assignee: FUJI ELECTRIC CO., LTD.Inventors: Tomohiro Moriya, Hitoshi Nakata, Takehito Shimatsu
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Patent number: 10317480Abstract: A magneto resistive device having a plurality of magneto resistive sensing elements. Each of the plurality of magneto resistive sensing elements has a free layer and a reference layer. The free layer has a rounded convex contour with an aspect ratio of 2 or greater. There may be one hundred or more magneto resistive sensing elements.Type: GrantFiled: October 13, 2015Date of Patent: June 11, 2019Assignee: Infineon Technologies AGInventors: Wolfgang Raberg, Andreas Strasser
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Patent number: 10249817Abstract: A magnetic device includes a free layer; a pinned layer; a tunnel barrier disposed between the free layer and the pinned layer; a polarization enhancement layer disposed between the tunnel barrier and the pinned layer; and a blocking layer disposed between the polarization enhancement layer and the pinned layer, wherein the blocking layer includes a first diffusion trap layer and a second diffusion trap layer disposed on the first diffusion trap layer.Type: GrantFiled: August 15, 2017Date of Patent: April 2, 2019Assignee: Samsung Electronics Co., Ltd.Inventors: Ki-woong Kim, Kee-won Kim, Se-chung Oh, Yong-sung Park, Ju-hyun Kim
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Patent number: 9966529Abstract: A magnetic tunnel junction (MTJ) is disclosed wherein first and second interfaces of a free layer (FL) with a first metal oxide (Hk enhancing layer) and second metal oxide (tunnel barrier), respectively, produce perpendicular magnetic anisotropy (PMA) to increase thermal stability. In some embodiments, metal clusters are formed in the FL and are subsequently partially or fully oxidized by scavenging oxygen to generate additional FL/oxide interfaces that enhance PMA, provide an acceptable resistance x area (RA) value, and preserve the magnetoresistive ratio. In other embodiments, a continuous or discontinuous metal (M) or MQ alloy layer within the FL reacts with scavenged oxygen to form a partially oxidized metal or alloy layer that enhances PMA and maintains acceptable RA. M is one of Mg, Al, B, Ca, Ba, Sr, Ta, Si, Mn, Ti, Zr, or Hf, and Q is a transition metal, B, C, or Al.Type: GrantFiled: March 17, 2017Date of Patent: May 8, 2018Assignee: Headway Technologies, Inc.Inventors: Jodi Mari Iwata, Guenole Jan, Ru-Ying Tong, Po-Kang Wang
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Patent number: 9865801Abstract: Integrated circuits and methods of producing the same are provided. In an exemplary embodiment, a method of producing an integrated circuit includes forming a fixed layer that includes a magnetic material overlying a substrate. A non-magnetic first tunnel barrier layer is formed overlying the fixed layer. A total free layer is formed overlying the first tunnel barrier layer, where the total free layer includes a first spacer layer between first and second free layers. The first free layer includes one or more of cobalt, iron, and boron. The first spacer layer is non-magnetic and includes a first spacer layer boron sink material that has a boride formation enthalpy lower than the boride formation enthalpy of cobalt.Type: GrantFiled: January 19, 2017Date of Patent: January 9, 2018Assignee: GLOBALFOUNDRIES SINGAPORE PTE. LTD.Inventors: Kazutaka Yamane, Vinayak Bharat Naik, Kangho Lee
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Patent number: 9799822Abstract: A disclosed magnetic memory element includes: a magnetization free layer formed of a ferromagnetic substance having perpendicular magnetic anisotropy; a response layer provided so as to be opposed to the magnetization free layer and formed of a ferromagnetic substance having perpendicular magnetic anisotropy; a non-magnetic layer provided so as to be opposed to the response layer on a side opposite to the magnetization free layer and formed of a non-magnetic substance; and a reference layer provided so as to be opposed to the non-magnetic layer on a side opposite to the response layer and formed of a ferromagnetic substance having perpendicular magnetic anisotropy. The magnetization free layer includes a first magnetization fixed region and a second magnetization fixed region which have magnetization fixed in directions antiparallel to each other, and a magnetization free region in which a magnetization direction is variable.Type: GrantFiled: April 19, 2012Date of Patent: October 24, 2017Assignees: NEC CORPORATION, TOHOKU UNIVERSITYInventors: Shunsuke Fukami, Nobuyuki Ishiwata, Tadahiko Sugibayashi, Hideo Ohno, Shoji Ikeda, Michihiko Yamanouchi
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Patent number: 9490422Abstract: Magnetoresistive random access memory (MRAM) devices and methods for making the same include growing a tunnel barrier layer on a first magnetic layer. A thin layer of non-wetting material is formed on the tunnel barrier layer, such that the non-wetting material forms distinct regions on the tunnel barrier layer. A second magnetic layer is grown on the tunnel barrier layer.Type: GrantFiled: July 30, 2015Date of Patent: November 8, 2016Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Guohan Hu, Daniel C. Worledge
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Patent number: 9466785Abstract: Magnetoresistive random access memory (MRAM) devices and methods for making the same include growing a tunnel barrier layer on a first magnetic layer. A thin layer of non-wetting material is formed on the tunnel barrier layer, such that the non-wetting material forms distinct regions on the tunnel barrier layer. A second magnetic layer is grown on the tunnel barrier layer.Type: GrantFiled: July 30, 2015Date of Patent: October 11, 2016Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATIONInventors: Guohan Hu, Daniel C. Worledge
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Patent number: 9379317Abstract: Method of filtering electrons to obtain spin-polarization of a current conducting at least 75% of electrons at the Fermi level, used with a spin-polarized current source comprising: a polarized spin injection device comprising an electrically conducting substrate of which a first face has magnetic properties and an organic layer in contact with the first face of the substrate; an electrically conducting material called the ground, the organic layer being arranged between the ground and the substrate; a current source electrically connected to the first face of the substrate and the ground; the method comprising circulation of the electron conduction current by means of the current source, between the first face of the substrate and the ground, at a temperature higher than ?220° C.Type: GrantFiled: April 15, 2013Date of Patent: June 28, 2016Assignees: Centre National de la Recherche Scientifique, Universite de StrasbourgInventors: Martin Bowen, Wolfgang Weber, Loïc Joly, Eric Beaurepaire, Fabrice Scheurer, Samy Boukari, Mébarek Alouani
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Patent number: 9087977Abstract: A semiconductor device is provided having a free layer and a pinned layer spaced apart from each other. A tunnel barrier layer is formed between the free layer and the pinned layer. The pinned layer may include a lower pinned layer, and an upper pinned layer spaced apart from the lower pinned layer. A spacer may be formed between the lower pinned layer and the upper pinned layer. A non-magnetic junction layer may be disposed adjacent to the spacer or between layers in the upper or lower pinned layer.Type: GrantFiled: April 16, 2014Date of Patent: July 21, 2015Assignee: SAMSUNG ELECTRONICS CO., LTD.Inventors: Jeong-Heon Park, Ki-Woong Kim, Hee-Ju Shin, Joon-Myoung Lee, Woo-Jin Kim, Jae-Hoon Kim, Se-Chung Oh, Yun-Jae Lee
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Patent number: 9028910Abstract: The present invention is directed to a method for manufacturing spin transfer torque magnetic random access memory (STTMRAM) devices. The method, which utilizes in-situ annealing and etch-back of the magnetic tunnel junction (MTJ) film stack, comprises the steps of depositing a barrier layer on top of a bottom magnetic layer and then depositing an interface magnetic layer on top of the barrier layer to form an MTJ film stack; annealing the MTJ film stack at a first temperature and then cool the MTJ film stack to a second temperature lower than the first temperature; etching away a top portion of the interface magnetic layer; and depositing at least one top layer on top of the etched interface magnetic layer. The method may further include the step of annealing the MTJ film stack at a third temperature between the first and second temperature after the step of depositing at least one top layer.Type: GrantFiled: May 8, 2014Date of Patent: May 12, 2015Assignee: Avalanche Technology, Inc.Inventors: Yuchen Zhou, Yiming Huai
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Patent number: 9017832Abstract: Various embodiments may be generally directed to a magnetic element capable of optimized magnetoresistive data reading. Such a magnetic element may be configured at least with a magnetoresistive stack that has an electrode lamination having at least a transition metal layer disposed between a magnetically free layer of the magnetoresistive stack and an electrode layer of the electrode lamination.Type: GrantFiled: January 31, 2013Date of Patent: April 28, 2015Assignee: Seagate Technology LLCInventors: Eric Walter Singleton, Liwen Tan, Jae-Young Yi
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Patent number: 9017831Abstract: A thin-film magnetic oscillation element includes a pinned magnetic layer, a free magnetic layer, a nonmagnetic spacer layer provided between the pinned magnetic layer and the free magnetic layer, and a pair of electrodes, in which the easy axis of magnetization of the pinned magnetic layer lies in an in-plane direction of the plane of the pinned magnetic layer, and the easy axis of magnetization of the free magnetic layer lies in a direction normal to the plane of the free magnetic layer. Preferably, the relationship between the saturation magnetization Ms and the magnetic anisotropy field Ha of the free magnetic layer satisfies 1.257 Ms<Ha<12.57 Ms. More preferably, the free magnetic layer is composed of an alloy or a stacked film containing at least one element selected from Co, Ni, Fe, and B.Type: GrantFiled: February 27, 2013Date of Patent: April 28, 2015Assignee: TDK CorporationInventors: Katsuyuki Nakada, Takahiro Suwa, Kuniyasu Ito, Yuji Kakinuma, Masato Takahashi
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Publication number: 20140374860Abstract: Provided is a magnetic shield having improved shielding properties from an external magnetic field. A magnetic shield MS1 has in-plane magnetization as remanent magnetization, and is adapted to generate a perpendicular component in the magnetization direction by applying a magnetic field in the perpendicular direction to the magnetic shield.Type: ApplicationFiled: June 5, 2014Publication date: December 25, 2014Applicant: RENESAS ELECTRONICS CORPORATIONInventor: Tetsuhiro SUZUKI
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Patent number: 8917581Abstract: Articles of manufacture and methods of manufacturing such articles of manufacture are disclosed. The articles of manufacture may include a heat assisted magnetic recording (HAMR) transducer having a near field transducer (NFT) and a chimney thermally coupled to the NFT. The articles of manufacture may also include an electrical conductor having section with a reduced width that is thermally coupled to the chimney. The methods include applying an electrical current to the electrical conductor to generate heat in the section and annealing the chimney and the NFT from the heat generated.Type: GrantFiled: January 17, 2014Date of Patent: December 23, 2014Assignee: Western Digital Technologies, Inc.Inventor: Michael L. Mallary
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Patent number: 8911888Abstract: Magnetic memories and methods are disclosed. A magnetic memory as described herein includes a plurality of stacked data storage layers to form a three-dimensional magnetic memory. The data storage layers are each formed from a multi-layer structure. At ambient temperatures, the multi-layer structures exhibit an antiparallel coupling state with a near zero net magnetic moment. At higher transition temperatures, the multi-layer structures transition from the antiparallel coupling state to a parallel coupling state with a net magnetic moment. At yet higher temperatures, the multi-layer structure transitions from the antiparallel coupling state to a receiving state where the coercivity of the multi-layer structures drops below a particular level so that magnetic fields from write elements or neighboring data storage layers may imprint data into the data storage layer.Type: GrantFiled: December 16, 2007Date of Patent: December 16, 2014Assignee: HGST Netherlands B.V.Inventors: Olav Hellwig, Bruce D. Terris, Jan-Ulrich Thiele
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Patent number: 8895161Abstract: A ferromagnetic graphene includes at least one antidot such that the ferromagnetic graphene has ferromagnetic characteristics. A spin valve device includes a ferromagnetic graphene. The ferromagnetic graphene includes a first region, a second region, and a third region. At least one antidot is formed in each of the first region and the third region. The first region and the third region are ferromagnetic regions, whereas the second region is a non-ferromagnetic region.Type: GrantFiled: May 30, 2012Date of Patent: November 25, 2014Assignee: Samsung Electronics Co., Ltd.Inventor: Sung-Hoon Lee
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Patent number: 8871365Abstract: Enhanced Hc and Hk in addition to higher thermal stability to 400° C. are achieved in magnetic devices by adding dusting layers on top and bottom surfaces of a spacer in a synthetic antiferromagnetic (SAF) structure to give a RL1/DL1/spacer/DL2/RL2 reference layer configuration where RL1 and RL2 layers exhibit perpendicular magnetic anisotropy (PMA), the spacer induces antiferromagnetic coupling between RL1 and RL2, and DL1 and DL2 are dusting layers that enhance PMA. RL1 and RL2 layers are selected from laminates such as (Ni/Co)n, L10 alloys, or rare earth-transition metal alloys. The reference layer may be incorporated in STT-MRAM memory elements or in spintronic devices including a spin transfer oscillator. Dusting layers and a similar SAF design may be employed in a free layer for Ku enhancement and to increase the retention time of a memory cell.Type: GrantFiled: February 28, 2012Date of Patent: October 28, 2014Assignee: Headway Technologies, Inc.Inventors: Yu-Jen Wang, Witold Kula, Ru Ying Tong, Guenole Jan
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Patent number: 8852676Abstract: A spin toque transfer magnetic random access memory (STTMRAM) element and a method of manufacturing the same is disclosed having a free sub-layer structure with enhanced internal stiffness. A first free sub-layer is deposited, the first free sub-layer being made partially of boron (B), annealing is performed of the STTMRAM element at a first temperature after depositing the first free sub-layer to reduce the B content at an interface between the first free sub-layer and the barrier layer, the annealing causing a second free sub-layer to be formed on top of the first free sub-layer and being made partially of B, the amount of B of the second free sub-layer being greater than the amount of B in the first free sub-layer.Type: GrantFiled: October 11, 2013Date of Patent: October 7, 2014Assignee: Avalanche Technology, Inc.Inventor: Yuchen Zhou
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Patent number: 8829901Abstract: A method to measure a magnetic field is provided. The method includes applying an alternating drive current to a drive strap overlaying a magnetoresistive sensor to shift an operating point of the magnetoresistive sensor to a low noise region. An alternating magnetic drive field is generated in the magnetoresistive sensor by the alternating drive current. When the magnetic field to be measured is superimposed on the alternating magnetic drive field in the magnetoresistive sensor, the method further comprises extracting a second harmonic component of an output of the magnetoresistive sensor. The magnetic field to be measured is proportional to a signed amplitude of the extracted second harmonic component.Type: GrantFiled: November 4, 2011Date of Patent: September 9, 2014Assignee: Honeywell International Inc.Inventor: Bharat B. Pant
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Patent number: 8755152Abstract: A method and system for providing a magnetic transducer is described. The method and system include providing a magnetic shield, an insertion layer on the magnetic shield, an antiferromagnetic (AFM) layer, a pinned layer magnetically coupled with the AFM layer, a nonmagnetic spacer layer, and a free layer. The magnetic shield has a texture and a grain size. The insertion layer has a thickness that is sufficiently large that the AFM layer is magnetically decoupled from the magnetic shield and sufficiently small that the AFM layer is structurally coupled with the magnetic shield. The pinned layer resides between the AFM layer and the nonmagnetic spacer layer. The nonmagnetic spacer layer resides between the free layer and the pinned layer.Type: GrantFiled: September 24, 2008Date of Patent: June 17, 2014Assignee: Western Digital (Fremont), LLCInventors: Chando Park, Qunwen Leng, Min Zhou, Sangmun Oh, Mahendra Pakala
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Patent number: 8709617Abstract: In accordance with one aspect of the invention, a magnetic memory element records information in a spin valve structure having a free layer, a pinning layer, and a nonmagnetic layer sandwiched therebetween. The magnetic memory element further has, on the free layer, a separate nonmagnetic layer and a magnetic change layer having magnetic characteristics which change according to temperature. Multiple cutouts, including one cutout with a different shape, are provided in a peripheral portion of the spin valve structure. A method of driving the magnetic memory element is characterized in that information is recorded by applying unipolar electric pulses.Type: GrantFiled: September 5, 2008Date of Patent: April 29, 2014Assignee: Fuji Electric Co., Ltd.Inventors: Yasushi Ogimoto, Haruo Kawakami
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Patent number: 8679653Abstract: A spin-valve element has a pair of ferromagnetic layers having mutually different coercive forces, sandwiching an insulating layer or a nonmagnetic layer therebetween. The in-plane shape of the spin-valve element is substantially circular in shape but is provided, in the peripheral portion, with a plurality of cutouts NS, NW, NE, NN. Preferably, the shape of at least one cutout be made different from that of others. Moreover, a storage device that employs such a spin-valve element is provided.Type: GrantFiled: September 5, 2008Date of Patent: March 25, 2014Assignee: Fuji Electric Co., Ltd.Inventors: Haruo Kawakami, Yasushi Ogimoto
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Patent number: 8637170Abstract: A magnetic sensor comprises a support; a nonmagnetic conductive layer disposed on the support; a fixed magnetization layer disposed on a first part of the nonmagnetic conductive layer and on the support; a free magnetization layer disposed on a second part of the nonmagnetic conductive layer different from the first part and on the support; and a nonmagnetic low resistance layer, disposed on a part overlapping the nonmagnetic conductive layer in at least one of the fixed magnetization layer and free magnetization layer, having an electrical resistivity lower than that of the one layer.Type: GrantFiled: May 26, 2009Date of Patent: January 28, 2014Assignee: TDK CorporationInventor: Tomoyuki Sasaki
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Patent number: 8582249Abstract: A magnetic element has a magnetically responsive lamination with a ferromagnetic free layer separated from a synthetic antiferromagnetic (SAF) layer by a spacer layer and from a sensed data bit stored in an adjacent medium by an air bearing surface (ABS). The lamination is coupled to at least one antiferromagnetic (AFM) tab a predetermined offset distance from the ABS.Type: GrantFiled: April 26, 2011Date of Patent: November 12, 2013Assignee: Seagate Technology LLCInventors: Victor Boris Sapozhnikov, Eric Walter Singleton, Mark William Covington
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Patent number: 8558623Abstract: An oscillator including two groups of elementary junctions having giant magnetoresistance effect traversed by electric currents, the junctions of each of the two groups being in series and energized by respective main currents and the voltages across the terminals of the groups being added together to provide a voltage on an output of the oscillating circuit. The voltage across the terminals of one or more junctions of a first group is applied to a first input of a phase comparator and the voltage across the terminals of one or more junctions of the other group is applied to another input of the phase comparator, the phase comparator providing on two outputs secondary currents of the same amplitude and of opposite signs, which are dependent on the mean phase difference between the voltages applied to the inputs, the secondary currents each being added to a respective main current.Type: GrantFiled: December 15, 2011Date of Patent: October 15, 2013Assignee: Commissariat a l'Energie Atomique et aux Energies AlternativesInventors: Mykhailo Zarudniev, Eric Colinet, Patrick Villard
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Patent number: 8507113Abstract: The present invention is directed to align crystal c-axes in magnetic layers near two opposed junction wall surfaces of a magnetoresistive element so as to be almost perpendicular to the junction wall surfaces. A magnetic sensor stack body has, on sides of opposed junction wall surfaces of a magnetoresistive element, field regions for applying a bias magnetic field to the element. The field region has first and second magnetic layers having magnetic particles having crystal c-axes, the first magnetic layer is disposed adjacent to the junction wall surface in the field region, the crystal c-axes in the first magnetic layer are aligned and oriented along an ABS in a film plane, the second magnetic layer is disposed adjacent to the first magnetic layer in the field region, and the crystal c-axis directions in the second magnetic layer are distributed at random in a plane.Type: GrantFiled: May 28, 2010Date of Patent: August 13, 2013Assignee: Canon Anelva CorporationInventors: Einstein Noel Abarra, Tetsuya Endo
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Patent number: 8490279Abstract: A method of forming a hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed. A HB layer is formed with easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield is deposited on the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading.Type: GrantFiled: September 24, 2010Date of Patent: July 23, 2013Assignee: Headway Technologies, Inc.Inventors: Yuchen Zhou, Kenichi Takano, Kunliang Zhang
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Publication number: 20130170068Abstract: A head for magnetic data recording that includes an embedded contact sensor. The embedded contact sensor detects head disk contact by detecting changes in temperature as a result of contact between the head and the disk. The embedded contact sensor includes a thermoresistive layer and a structure for pinning the magnetic domains of the thermoresistive layer. This pinning of the magnetic domains prevents the thermoresistive layer from changing resistance in response to magnetic fields (rather than temperature) so as to avoid unwanted signal noise as a result of a magnetic signal from the magnetic media.Type: ApplicationFiled: December 28, 2011Publication date: July 4, 2013Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Shoji Natori
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Patent number: 8435652Abstract: A magnetic stack structure is disclosed. The magnetic stack structure includes two metal layers and a free layer sandwiched by the two metal layers. The thickness of the free layer is 1-30 nm. The thickness of the metal layers are 0.1-20 nm respectively.Type: GrantFiled: July 9, 2009Date of Patent: May 7, 2013Assignee: National Yunlin University of Science and TechnologyInventors: Te-Ho Wu, Lin-Hsiu Ye, Ching-Ming Lee
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Patent number: 8404367Abstract: A dual spin filter that minimizes spin-transfer magnetization switching current (Jc) while achieving a high dR/R in STT-RAM devices is disclosed. The bottom spin valve has a MgO tunnel barrier layer formed with a natural oxidation process to achieve low RA, a CoFe/Ru/CoFeB—CoFe pinned layer, and a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel (NCC) layer to minimize Jc0. The NCC layer may have be a composite wherein conductive M(Si) grains are magnetically coupled with adjacent ferromagnetic layers and are formed in an oxide, nitride, or oxynitride insulator matrix. The upper spin valve has a Cu spacer to lower the free layer damping constant. A high annealing temperature of 360° C. is used to increase the MR ratio above 100%. A Jc0 of less than 1×106 A/cm2 is expected based on quasistatic measurements of a MTJ with a similar MgO tunnel barrier and composite free layer.Type: GrantFiled: October 19, 2011Date of Patent: March 26, 2013Assignee: MagIC Technologies, Inc.Inventors: Cheng T. Horng, Ru-Ying Tong
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Patent number: 8361541Abstract: The subject matter disclosed herein provides methods for manufacturing an electronic lapping guide and a magnetic read head assembly. The magnetoresistive head assembly includes a sensing element that has a front edge and a front flux guide that has a back edge, such that the sensing element front edge and the front flux guide back edge share a common interface that defines an interface plane normal to the surface of a wafer substrate. The electronic lapping guide comprises a conductive material adapted to attach to two electrical leads for measuring a resistance through the conductive material. The conductive material may include a conductive material back edge aligned with the interface plane. The resistance of the conductive material may be inversely proportional to a conductive material length normal to the interface plane.Type: GrantFiled: July 28, 2009Date of Patent: January 29, 2013Assignee: HGST Netherlands B.V.Inventors: Edward Hin Pong Lee, David John Seagle
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Patent number: 8295006Abstract: A magnetic sensor reduces thermal fluctuation and realizes high-sensitive signal detection using a spin Hall device of a simple structure configured with only one magnetic layer. The magnetic sensor includes a stacked film in which a nonmagnetic spin Hall layer, a nonmagnetic insulator layer, and a magnetic layer are stacked, an electrode nonmagnetic terminal pair connected to a side surface of the nonmagnetic spin Hall layer, and a unit applying a current in a film thickness direction of the stacked film. A thickness of the nonmagnetic spin Hall layer is thinner than twice a spin diffusion length of a material constituting the nonmagnetic spin Hall layer. A magnetization direction of the magnetic layer magnetized by an external magnetic field is detected due to the polarity of a voltage across both ends of the electrode nonmagnetic terminal pair.Type: GrantFiled: December 16, 2008Date of Patent: October 23, 2012Assignee: Hitachi, Ltd.Inventors: Ryoko Sugano, Masahiko Ichimura, Hiromasa Takahashi
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Patent number: 8274811Abstract: A spin transfer oscillator (STO) structure is disclosed that includes two assist layers with perpendicular magnetic anisotropy (PMA) to enable a field generation layer (FGL) to achieve an oscillation state at lower current density for MAMR applications. In one embodiment, the STO is formed between a main pole and write shield and the FGL has a synthetic anti-ferromagnetic structure. The STO configuration may be represented by seed layer/spin injection layer (SIL)/spacer/PMA layer 1/FGL/spacer/PMA layer 2/capping layer. The spacer may be Cu for giant magnetoresistive (GMR) devices or a metal oxide for tunneling magnetoresistive (TMR) devices. Alternatively, the FGL is a single ferromagnetic layer and the second PMA assist layer has a synthetic structure including two PMA layers with magnetic moment in opposite directions in a seed layer/SIL/spacer/PMA assist 1/FGL/spacer/PMA assist 2/capping layer configuration. SIL and PMA assist layers are laminates of (CoFe/Ni)x or the like.Type: GrantFiled: November 22, 2010Date of Patent: September 25, 2012Assignee: Headway Technologies, Inc.Inventors: Kunliang Zhang, Min Li, Yuchen Zhou
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Patent number: 8242776Abstract: A semiconductor process and apparatus provide a high-performance magnetic field sensor from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216), where each differential sensor (e.g., 201) is formed from a Wheatstone bridge structure with four unshielded MTJ sensors (202-205), each of which includes a magnetic field pulse generator (e.g., 414) for selectively applying a field pulse to stabilize or restore the easy axis magnetization of the sense layers (e.g., 411) to eliminate micromagnetic domain switches during measurements of small magnetic fields.Type: GrantFiled: March 26, 2008Date of Patent: August 14, 2012Assignee: Everspin Technologies, Inc.Inventors: Phillip G. Mather, Young Sir Chung, Bradley N. Engel
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Publication number: 20120182647Abstract: According to one embodiment, a magnetoresistive element includes a first ferromagnetic layer a magnetization direction of which is pinned, a second ferromagnetic layer a magnetization direction of which is changed depending on an external magnetic field, an intermediate layer arranged between the first ferromagnetic layer and the second ferromagnetic layer and including an insulating layer and a magnetic conductive column, an alloy layer formed between the magnetic conductive column in the intermediate layer and the second ferromagnetic layer and including at least one of FeCoAl and FeCoAlCu, and a pair of electrodes configured to supply a current perpendicularly to a film plane of a stacked film including the first ferromagnetic layer, the intermediate layer, the alloy layer and the second ferromagnetic layer.Type: ApplicationFiled: January 30, 2012Publication date: July 19, 2012Inventors: Hiromi Fuke, Susumu Hashimoto, Masayuki Takagishi, Hitoshi Iwasaki
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Patent number: 8158190Abstract: Techniques for attaining high performance magnetic memory devices are provided. In one aspect, a magnetic memory device comprising one or more free magnetic layers is provided. The one or more free magnetic layers comprise a low magnetization material adapted to have a saturation magnetization of less than or equal to about 600 electromagnetic units per cubic centimeter. The device may be configured such that a ratio of mean switching field associated with an array of non-interacting magnetic memory devices and a standard deviation of the switching field is greater than or equal to about 20. The magnetic memory device may comprise a magnetic random access memory (MRAM) device. A method of producing a magnetic memory device is also provided.Type: GrantFiled: May 30, 2008Date of Patent: April 17, 2012Assignee: International Business Machines CorporationInventor: David W. Abraham
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Patent number: 8105703Abstract: The conventional free layer in a CPP GMR or TMR read head has been replaced by a tri-layer laminate comprising Co rich CoFe, moderately Fe rich NiFe, and heavily Fe rich NiFe. The result is an improved device that has a higher MR ratio than prior art devices, while still maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is described.Type: GrantFiled: June 19, 2008Date of Patent: January 31, 2012Assignee: Headway Technologies, Inc.Inventors: Hui-Chuan Wang, Min Li, Tong Zhao, Kunliang Zhang, Chyu-Jiuh Torng
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Patent number: 8057925Abstract: A dual spin filter that minimizes spin-transfer magnetization switching current (Jc) while achieving a high dR/R in STT-RAM devices is disclosed. The bottom spin valve has a MgO tunnel barrier layer formed with a natural oxidation process to achieve low RA, a CoFe/Ru/CoFeB—CoFe pinned layer, and a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel (NCC) layer to minimize Jc0. The NCC layer may have be a composite wherein conductive M(Si) grains are magnetically coupled with adjacent ferromagnetic layers and are formed in an oxide, nitride, or oxynitride insulator matrix. The upper spin valve has a Cu spacer to lower the free layer damping constant. A high annealing temperature of 360° C. is used to increase the MR ratio above 100%. A Jc0 of less than 1×106 A/cm2 is expected based on quasistatic measurements of a MTJ with a similar MgO tunnel barrier and composite free layer.Type: GrantFiled: March 27, 2008Date of Patent: November 15, 2011Assignee: MagIC Technologies, Inc.Inventors: Cheng T. Horng, Ru-Ying Tong
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Patent number: 8049567Abstract: A circuit comprising a DC current source and at least two spin torque oscillators, the at least two spin torque oscillators being electrically coupled to each other and to the DC current source. A circuit comprising phase shifting means is connected in such a way as to cause a phase shift between current and voltage through the spin torque oscillators. An advantage is that the controlled phase shift significantly increases the tolerance for deviating anisotropy fields, which makes manufacturing of spin torque oscillator devices much more feasible in practice.Type: GrantFiled: October 31, 2008Date of Patent: November 1, 2011Inventors: Johan Persson, Yan Zhou, Johan Åkerman
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Patent number: 7951415Abstract: A pole layer has an end located in a medium facing surface, the end having: a first side close to a substrate; a second side located opposite to the first side; a third side connecting an end of the first side to an end of the second side; and a fourth side connecting the other end of the first side to the other end of the second side. The second side defines a track width. The end of the pole layer located in the medium facing surface has a width that decreases toward the first side. The pole layer is disposed in a groove of a pole-layer-encasing layer made of a nonmagnetic insulating material, with a nonmagnetic conductive film provided between the encasing layer and the pole layer. The pole layer incorporates: a first layer located closer to the surface of the groove; and a second layer located farther from the surface of the groove.Type: GrantFiled: August 15, 2008Date of Patent: May 31, 2011Assignee: Headway Technologies, Inc.Inventors: Yoshitaka Sasaki, Dong-Hong Li, Shigeki Tanemura, Hiroyuki Itoh
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Patent number: 7948717Abstract: A magneto-resistance effect element includes a first magnetic layer of which a magnetization direction is fixed; a second magnetic layer of which a magnetization direction is fixed; an intermediate layer which is provided between the first magnetic layer and the second magnetic layer; and a pair of electrodes for flowing a current perpendicular to a film surface of the resultant laminated body comprised of the first magnetic layer, the second magnetic layer and the intermediate layer. The intermediate layer includes insulating portions and metallic portions containing at least one selected from the group consisting of Fe, Co, Ni, Cr and the metallic portions are contacted with the first magnetic layer and the second magnetic layer.Type: GrantFiled: September 7, 2007Date of Patent: May 24, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Hideaki Fukuzawa, Yoshihiko Fuji
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Publication number: 20110096443Abstract: A MTJ for a spintronic device is disclosed and includes a thin composite seed layer made of at least Ta and a metal layer having fcc(111) or hcp(001) texture as in Ta/Ti/Cu to enhance perpendicular magnetic anisotropy (PMA) in an overlying laminated layer with a (CoFe/Ni)X, (Co/NiFe)X, (Co/NiCo)X, (CoFe/NiFe)X, or (CoFe/NiCo)X composition where x is from 5 to 30. In one embodiment, a CPP-TMR spin valve has one or both of a laminated free layer and laminated reference layer with the aforementioned compositions. The MTJ includes an interfacial layer made of CoFeB, CoFeB/CoFe, or CoFe/CoFeB between each laminated structure and the tunnel barrier. The laminated layers are deposited by a low power and high Ar pressure process to avoid damaging interfaces between adjoining layers. Annealing occurs at 220° C. to 400° C. A laminated layer with high PMA may also be included in one or more layers of a spin transfer oscillator.Type: ApplicationFiled: October 26, 2009Publication date: April 28, 2011Inventors: Kunliang Zhang, Min Li, Pokang Wang, Yuchen Zhou, Cheng T. Horng, Ru-Ying Tong
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Patent number: 7906231Abstract: Magnetic tunneling devices are formed from a first body centered cubic (bcc) magnetic layer and a second bcc magnetic layer. At least one spacer layer of bcc material between these magnetic layers exchange couples the first and second bcc magnetic layers. A tunnel barrier in proximity with the second magnetic layer permits spin-polarized current to pass between the tunnel barrier and the second layer; the tunnel barrier may be either MgO and Mg—ZnO. The first magnetic layer, the spacer layer, the second magnetic layer, and the tunnel barrier are all preferably (100) oriented. The MgO and Mg—ZnO tunnel barriers are prepared by first depositing a metallic layer on the second magnetic layer (e.g., a Mg layer), thereby substantially reducing the oxygen content in this magnetic layer, which improves the performance of the tunnel barriers.Type: GrantFiled: October 31, 2007Date of Patent: March 15, 2011Assignee: International Business Machines CorporationInventor: Stuart Stephen Papworth Parkin
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Patent number: 7897200Abstract: The present invention provides a ferromagnetic/antiferromagnetic coupling film structure and a fabrication method thereof. The structure includes an antiferromagnetic layer of cobalt oxide having a thickness of 2 to 15 monolayers and formed on a substrate at a temperature ranging from 700K to 900K; and a ferromagnetic layer of cobalt having a thickness of at least one monolayer for being formed on the antiferromagnetic layer of cobalt oxide.Type: GrantFiled: July 31, 2008Date of Patent: March 1, 2011Assignee: National Chung Cheng UniversityInventors: Jyh-Shen Tsay, Chi-Wei Lee, Gung Chern
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Patent number: 7870659Abstract: A method for defining a perpendicular magnetic head is provided. The method includes forming a portion of the read and write head including depositing a sensor film on a surface only over a region of the read head to form a sensor; depositing a full-film shaping pole layer over the write head; defining a track width of the sensor; patterning a photoresist to define a pole tip of the write head including write track width and flare position, and at the same time to define a back edge of the sensor; removing material of the sensor and pole tip from the areas not covered by the photoresist; completing the fabrication of the write and read head layers; and lapping the write pole concurrently with the sensor to define the flare position of the pole tip and to define a sensor height with accurate positioning of write head flare.Type: GrantFiled: September 7, 2007Date of Patent: January 18, 2011Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventors: Vladimir Nikitin, Samuel Wei-san Yuan