Having Tunnel Junction Effect Patents (Class 360/324.2)
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Patent number: 8576518Abstract: A current-perpendicular-to-the-plane magnetoresistive sensor has an exchange-coupled side shield structure on each of two side regions of the sensor and an exchange-coupled top shield structure on the sensor and the two exchange-coupled side shield structures. Each exchange-coupled structure comprises an antiferromagnetic layer and a shield of soft magnetically permeable material exchange-coupled with the antiferromagnetic layer. Each side shield and the top shield has its magnetization oriented generally parallel to the sensor front edge and generally parallel to the plane of the sensor's free ferromagnetic layer. The shields in each exchange-coupled side shield structure and the exchange-coupled top shield structure may be an antiparallel coupled structure of two magnetically permeable films separated by a nonmagnetic coupling film.Type: GrantFiled: October 30, 2012Date of Patent: November 5, 2013Assignee: HGST Netherlands B.V.Inventors: Alexander M. Zeltser, Stefan Maat
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Patent number: 8570691Abstract: In one embodiment, a tunnel magnetoresistance (TMR) head includes a lead layer above a substrate, a seed layer above the lead layer, an antiferromagnetic (AFM) layer above the seed layer, a first ferromagnetic layer above the AFM layer, a second ferromagnetic layer above the first ferromagnetic layer, a coupling layer between the first and second ferromagnetic layers, the coupling layer causing a magnetization of the second ferromagnetic layer to be coupled to a magnetization of the first ferromagnetic layer, a fixed layer above the second ferromagnetic layer, an insertion layer adjacent the fixed layer or in the fixed layer, a barrier layer above the fixed layer, a free layer above the barrier layer, and a cap layer above the free layer. In another embodiment, the insertion layer is from about 0.05 nm to 0.3 nm in thickness and includes Ta, Ti, Hf, and/or Zr, and the free layer includes CoFeB.Type: GrantFiled: April 7, 2011Date of Patent: October 29, 2013Assignee: HGST Netherlands B.V.Inventors: Masashige Sato, Kojiro Komagaki
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Patent number: 8564911Abstract: A magneto-resistive effect (MR) element includes: first and second magnetic layers in which a relative angle formed by magnetization directions changes according to an external magnetic field; and a spacer layer positioned between the first magnetic layer and the second magnetic layer. The spacer layer includes a main spacer layer composed of gallium oxide as a primary component and containing at least one metal element selected from a group of magnesium, zinc, indium and aluminum.Type: GrantFiled: February 17, 2011Date of Patent: October 22, 2013Assignee: TDK CorporationInventors: Hayato Koike, Tsutomu Chou, Yoshihiro Tsuchiya, Hironobu Matsuzawa
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Patent number: 8564080Abstract: A magnetic tunnel junction (MTJ) storage element may comprise a pinned layer stack and a first functional layer. The pinned layer stack is formed of a plurality of layers comprising a bottom pinned layer, a coupling layer, and a top pinned layer. The first functional layer is disposed in the bottom pinned layer or the top pinned layer.Type: GrantFiled: July 16, 2010Date of Patent: October 22, 2013Assignee: QUALCOMM IncorporatedInventors: Wei-Chuan Chen, Seung H. Kang, Xiaochun Zhu, Xia Li
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Patent number: 8563147Abstract: A hard bias (HB) structure for producing longitudinal bias to stabilize a free layer in an adjacent spin valve is disclosed and includes a composite seed layer made of at least Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (Co/Ni)X laminated layer. The (Co/Ni)X HB layer deposition involves low power and high Ar pressure to avoid damaging Co/Ni interfaces and thereby preserves PMA. A capping layer is formed on the HB layer to protect against etchants in subsequent process steps. After initialization, magnetization direction in the HB layer is perpendicular to the sidewalls of the spin valve and generates an Mrt value that is greater than from an equivalent thickness of CoPt. A non-magnetic metal separation layer may be formed on the capping layer and spin valve to provide an electrical connection between top and bottom shields.Type: GrantFiled: June 24, 2009Date of Patent: October 22, 2013Assignee: Headway Technologies, Inc.Inventors: Kunliang Zhang, Min Li, Yuchen Zhou, Min Zheng
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Patent number: 8558333Abstract: A method for manipulating domain pinning and reversal in a ferromagnetic material comprises applying an external magnetic field to a uniaxial ferromagnetic material comprising a plurality of magnetic domains, where each domain has an easy axis oriented along a predetermined direction. The external magnetic field is applied transverse to the predetermined direction and at a predetermined temperature. The strength of the magnetic field is varied at the predetermined temperature, thereby isothermally regulating pinning of the domains. A magnetic storage device for controlling domain dynamics includes a magnetic hard disk comprising a uniaxial ferromagnetic material, a magnetic recording head including a first magnet, and a second magnet. The ferromagnetic material includes a plurality of magnetic domains each having an easy axis oriented along a predetermined direction.Type: GrantFiled: July 9, 2010Date of Patent: October 15, 2013Assignees: The University of Chicago, UCL Business PLCInventors: Daniel M. Silevitch, Thomas F. Rosenbaum, Gabriel Aeppli
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Patent number: 8557407Abstract: A high performance TMR sensor is fabricated by incorporating a tunnel barrier having a Mg/MgO/Mg configuration. The 4 to 14 Angstroms thick lower Mg layer and 2 to 8 Angstroms thick upper Mg layer are deposited by a DC sputtering method while the MgO layer is formed by a NOX process involving oxygen pressure from 0.1 mTorr to 1 Torr for 15 to 300 seconds. NOX time and pressure may be varied to achieve a MR ratio of at least 34% and a RA value of 2.1 ohm-um2. The NOX process provides a more uniform MgO layer than sputtering methods. The second Mg layer is employed to prevent oxidation of an adjacent ferromagnetic layer. In a bottom spin valve configuration, a Ta/Ru seed layer, IrMn AFM layer, CoFe/Ru/CoFeB pinned layer, Mg/MgO/Mg barrier, CoFe/NiFe free layer, and a cap layer are sequentially formed on a bottom shield in a read head.Type: GrantFiled: August 6, 2010Date of Patent: October 15, 2013Assignee: Headway Technologies, Inc.Inventors: Tong Zhao, Kunliang Zhang, Hui Chuan Wang, Yu-Hsia Chen, Min Li
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Patent number: 8559141Abstract: A spin tunneling element includes a pinned layer, a barrier layer, and a free layer. The free layer includes a ferromagnetic layer including a ferromagnetic material that adjoins the barrier layer at a first interface. The free layer also includes a layer of amorphous material that adjoins the ferromagnetic layer at a second interface opposite the first interface. A first crystallization temperature of the ferromagnetic material at the first interface is lower than a second crystallization temperature at the second interface.Type: GrantFiled: May 7, 2007Date of Patent: October 15, 2013Assignee: Western Digital (Fremont), LLCInventors: Mahendra Pakala, Chando Park
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Patent number: 8555486Abstract: A method for fabricating a magnetic recording transducer is described. The transducer has an ABS location and a nonmagnetic intermediate layer having a pole trench. The method includes depositing at least one magnetic pole layer having a top surface and a pole tip portion proximate to the ABS location. A first portion of the magnetic pole layer(s) resides in the pole trench. The magnetic pole layer(s) have a seam in the pole tip portion that extends to the top surface. The method also includes cathodically etching a second portion of the magnetic pole layer(s) from the seam at a rate of not more than 0.1 nanometers/second, thereby forming a seam trench in the magnetic pole layer(s). The method also includes refilling the seam trench with at least one magnetic refill layer. At least an additional magnetic pole layer is deposited on the top surface and the magnetic refill layer(s).Type: GrantFiled: December 6, 2011Date of Patent: October 15, 2013Assignee: Western Digital (Fremont), LLCInventors: Jose A. Medina, Tiffany Yun Wen Jiang, Ming Jiang
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Patent number: 8553372Abstract: According to one embodiment, a magnetic oscillator includes a layered film and a pair of electrodes. The layered film includes a first ferromagnetic layer, an insulating layer stacked on the first ferromagnetic layer, and a second ferromagnetic layer stacked on the insulating layer. The pair of electrodes is configured to apply a current to the layered film in a direction perpendicular to a film surface of the layered film. Regions having different resistance area products are provided between the first ferromagnetic layer and the second ferromagnetic layer.Type: GrantFiled: March 26, 2012Date of Patent: October 8, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Tazumi Nagasawa, Kiwamu Kudo, Rie Sato, Koichi Mizushima
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Patent number: 8553371Abstract: Embodiments herein generally relate to TMR readers and methods for their manufacture. The embodiments discussed herein disclose TMR readers that utilize a structure that avoids use of the DLC layer over the sensor structure and over the hard bias layer. The capping structure over the sensor structure functions as both a protective layer for the sensor structure and a CMP stop layer. The hard bias capping structure functions as both a protective structure for the hard bias layer and as a CMP stop layer. The capping structures that are free of DLC reduce the formation of notches in the second shield layer so that second shield layer is substantially flat.Type: GrantFiled: November 24, 2010Date of Patent: October 8, 2013Assignee: HGST Netherlands B.V.Inventors: Honglin Zhu, Liubo Hong, Hicham M. Sougrati, Quang Le, Jui-Lung Li, Chando Park
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Patent number: 8551626Abstract: A magnetoresistive device having a high giant magnetoresistance (GMR) value and a moderate low resistance area product (RA) includes a first magnetic layer, a second magnetic layer, and a current confined path (CCP) spacer layer positioned between the first magnetic layer and the second magnetic layer. The spacer layer includes copper current confined paths extending between the first magnetic layer and the second magnetic layer in a matrix of magnesium oxide. The spacer layer is formed by a mixture copper and magnesium oxide, which is heattreated to form the copper current confined paths within the magnesium oxide matrix.Type: GrantFiled: June 25, 2009Date of Patent: October 8, 2013Assignee: Seagate Technology LLCInventors: Qing He, Yonghua Chen, Juren Ding
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Patent number: 8553370Abstract: The present invention generally relates to a TMR reader and a method for its manufacture. The TMR reader discussed herein adds a shield layer to the sensor structure. The shield layer is deposited over the capping layer so that the shield layer and the capping layer collectively protect the free magnetic layer within the sensor structure from damage during further processing. Additionally, the hard bias layer is shaped such that the entire hard bias layer underlies the hard bias capping layer so that a top lead layer is not present. By eliminating the top lead layer and including a shield layer within the sensor structure, the read gap is reduced while still protecting the free magnetic layer during later processing.Type: GrantFiled: November 24, 2010Date of Patent: October 8, 2013Assignee: HGST Netherlands B.V.Inventors: Liubo Hong, Honglin Zhu, Tsann Lin, Zheng Gao
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Patent number: 8545999Abstract: A method and system for providing a magnetoresistive structure are described. The magnetoresistive structure includes a first electrode, an insertion layer, a crystalline tunneling barrier layer, and a second electrode. The first electrode includes at least a first magnetic material and boron. The crystalline tunneling barrier layer includes at least one constituent. The insertion layer has a first boron affinity. The at least one constituent of the crystalline tunneling barrier layer has at least a second boron affinity that is less than the first boron affinity. The second electrode includes at least a second magnetic material.Type: GrantFiled: February 21, 2008Date of Patent: October 1, 2013Assignee: Western Digital (Fremont), LLCInventors: Qunwen Leng, Mahendra Pakala, Yong Shen
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Patent number: 8546897Abstract: A magnetic memory element includes a memory layer, a reference layer, and a spin-injection layer provided between the memory layer and the reference layer. The reference layer has a structure in which at least two CoPt layers containing 20 atomic % or more and 50 atomic % or less of Pt and having a thickness of 1 nm or more and 5 nm or less are stacked with a Ru layer provided therebetween. The thickness of the Ru layer is 0.45±0.05 nm or 0.9±0.1 nm. In addition, the axis of 3-fold crystal symmetry of the CoPt layers is oriented perpendicularly to the film surface. The reference layer includes a high spin polarization layer of 1.5 nm or less containing Co or Fe as a main component at an interface with the spin-injection layer.Type: GrantFiled: July 29, 2011Date of Patent: October 1, 2013Assignee: Sony CorporationInventors: Hiroyuki Ohmori, Masanori Hosomi, Kazuhiro Bessho, Yutaka Higo, Kazutaka Yamane, Hiroyuki Uchida
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Patent number: 8547666Abstract: Embodiments of the present invention aim suppress the generation of spin torque noise in a current perpendicular to plane magnetoresistive head. According to one embodiment, when sensing current is applied to a current perpendicular to plane magnetoresistive head from a free layer toward a first pinned layer, a configuration wherein the relative angle between the magnetization of a second pinned layer and the magnetization of the free layer is in the range of 70 to 80 degrees is used. Further, when sensing current is applied to a current perpendicular to plane magnetoresistive head from a first pinned layer toward a free layer, a configuration wherein the relative angle between the magnetization of a second pinned layer and the magnetization of the free layer is in the range of 100 to 110 degrees is used.Type: GrantFiled: August 3, 2007Date of Patent: October 1, 2013Assignee: HGST Netherlands BVInventors: Hiroyuki Katada, Hiroyuki Hoshiya
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Patent number: 8536668Abstract: A magnetic layer that includes a seed layer comprising at least tantalum and a free magnetic layer comprising at least iron. The free magnetic layer is grown on top of the seed layer and the free magnetic layer is perpendicularly magnetized. The magnetic layer may be included in a magnetic tunnel junction (MTJ) stack.Type: GrantFiled: August 9, 2012Date of Patent: September 17, 2013Assignee: International Business Machines CorporationInventor: Daniel C. Worledge
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Patent number: 8530987Abstract: A magnetic memory includes a magnetoresistive element. The magnetoresistive element includes a reference layer having an invariable magnetization direction, a storage layer having a variable magnetization direction, and a spacer layer provided between the reference layer and the storage layer. The storage layer has a multilayered structure including first and second magnetic layers, the second magnetic layer is provided between the first magnetic layer and the spacer layer and has a magnetic anisotropy energy lower than that of the first magnetic layer, and an exchange coupling constant Jex between the first magnetic layer and the second magnetic layer is not more than 5 erg/cm2.Type: GrantFiled: March 28, 2012Date of Patent: September 10, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Hisanori Aikawa, Tadashi Kai, Masahiko Nakayama, Sumio Ikegawa, Naoharu Shimomura, Eiji Kitagawa, Tatsuya Kishi, Jyunichi Ozeki, Hiroaki Yoda, Satoshi Yanagi
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Patent number: 8519498Abstract: A magnetic cell includes a ferromagnetic free layer having a free magnetization orientation direction and a first ferromagnetic pinned reference layer having a first reference magnetization orientation direction that is parallel or anti-parallel to the free magnetization orientation direction. A first oxide barrier layer is between the ferromagnetic free layer and the first ferromagnetic pinned reference layer. The magnetic cell further includes a second ferromagnetic pinned reference layer having a second reference magnetization orientation direction that is orthogonal to the first reference magnetization orientation direction. The ferromagnetic free layer is between the first ferromagnetic pinned reference layer and the second ferromagnetic pinned reference layer.Type: GrantFiled: September 13, 2012Date of Patent: August 27, 2013Assignee: Seagate Technology LLCInventors: Yuankai Zheng, Zheng Gao, Wenzhong Zhu, Wonjoon Jung, Haiwen Xi
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Patent number: 8518562Abstract: A magnetic storage device stable in write characteristic is provided. A first nonmagnetic film is provided over a recording layer. A first ferromagnetic film is provided over the first nonmagnetic film and has a first magnetization and a first film thickness. A second nonmagnetic film is provided over the first ferromagnetic film. A second ferromagnetic film is provided over the second nonmagnetic film, is coupled in antiparallel with the first ferromagnetic film, and has a second magnetization and a second film thickness. An antiferromagnetic film is provided over the second ferromagnetic film. The sum of the product of the first magnetization and the first film thickness and the product of the second magnetization and the second film thickness is smaller than the product of the magnetization of the recording layer and the film thickness of the recording layer.Type: GrantFiled: November 12, 2009Date of Patent: August 27, 2013Assignee: Renesas Electronics CorporationInventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Takada, Ryoji Matsuda, Yosuke Takeuchi
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Patent number: 8514525Abstract: A current-perpendicular-to-the-plane magnetoresistive (CPP MR) sensor has a shield layers that also functions as the sensor's reference layer. In a CPP MR disk drive read head, the shield layer has a fixed magnetization oriented substantially parallel to the air-bearing surface (ABS) of the slider that supports the read head. The quiescent magnetization of the sensor free layer is oriented at an angle relative to the magnetization of the shield layer, preferably between 120 and 150 degrees, to optimize the sensor response to magnetic fields from the recorded data bits on the disk. The magnetization of the free layer is biased by a biasing structure that includes a ferromagnetic side biasing layer formed near the side edges of the free layer and a ferromagnetic back biasing layer that is recessed from the ABS and has a magnetization oriented generally orthogonal to the ABS.Type: GrantFiled: September 13, 2010Date of Patent: August 20, 2013Assignee: HGST Netherlands B.V.Inventors: Jeffrey R. Childress, Jordan Asher Katine, Manfred Ernst Schabes
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Patent number: 8513751Abstract: A memory includes a semiconductor substrate. Magnetic tunnel junction elements are provided above the semiconductor substrate. Each of the magnetic tunnel junction elements stores data by a change in a resistance state, and the data is rewritable by a current. Cell transistors are provided on the semiconductor substrate. Each of the cell transistors is in a conductive state when the current is applied to the corresponding magnetic tunnel junction element. Gate electrodes are included in the respective cell transistors. Each of the gate electrodes controls the conductive state of the corresponding cell transistor. In active areas, the cell transistors are provided, and the active areas extend in an extending direction of intersecting the gate electrodes at an angle of (90-a tan(?)) degrees.Type: GrantFiled: March 14, 2012Date of Patent: August 20, 2013Assignee: Kabushiki Kaisha ToshibaInventor: Yoshiaki Asao
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Patent number: 8514527Abstract: According to one embodiment, a magnetoresistive effect head includes a magnetically pinned layer having a direction of magnetization that is pinned, a free magnetic layer positioned above the magnetically pinned layer, the free magnetic layer having a direction of magnetization that is free to vary, and a barrier layer comprising an insulator positioned between the magnetically pinned layer and the free magnetic layer, wherein at least one of the magnetically pinned layer and the free magnetic layer has a layered structure, the layered structure including a crystal layer comprising one of: a CoFe magnetic layer or a CoFeB magnetic layer and an amorphous magnetic layer comprising CoFeB and an element selected from: Ta, Hf, Zr, and Nb, wherein the crystal layer is positioned closer to a tunnel barrier layer than the amorphous magnetic layer. In another embodiment, a magnetic data storage system includes the magnetoresistive effect head described above.Type: GrantFiled: November 29, 2010Date of Patent: August 20, 2013Assignee: HGST Netherlands B.V.Inventors: Kojiro Komagaki, Katsumi Hoshino, Masashige Sato, Hiroyuki Hoshiya
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Patent number: 8513752Abstract: A magnetic tunnel junction includes an amorphous ferromagnetic reference layer having a first reference layer side and an opposing second reference layer side. The first reference layer side has a greater concentration of boron than the second reference layer side. A magnesium oxide tunnel barrier layer is disposed on the second side of the amorphous ferromagnetic reference layer. The magnesium oxide tunnel barrier layer has a crystal structure. An amorphous ferromagnetic free layer is disposed on the magnesium oxide tunnel barrier layer.Type: GrantFiled: September 13, 2012Date of Patent: August 20, 2013Assignee: Seagate Technology LLCInventors: Xilin Peng, Konstantin Nikolaev, Taras Pokhil, Victor Sapazhnikov, Yonghua Chen
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Patent number: 8498084Abstract: A magnetoresistive sensor having a novel free layer and a method of producing the same are disclosed. The magnetoresistive sensor comprises a pinned layer, a barrier layer disposed over the pinned layer, and a free layer disposed over the barrier layer. The free layer comprises a first magnetic layer disposed over the barrier layer. The first magnetic layer has a positive spin polarization, a positive magnetostriction, and a polycrystalline structure. The free layer further comprises a second magnetic layer disposed over the first magnetic layer. The second magnetic layer has a negative magnetostriction and comprises at least cobalt (Co) and boron (B).Type: GrantFiled: July 21, 2009Date of Patent: July 30, 2013Assignee: Western Digital (Fremont), LLCInventors: Qunwen Leng, Christian Kaiser, Yimin Guo, Mahendra Pakala, Sining Mao
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Patent number: 8497139Abstract: A magnetic memory device including a memory layer having a vertical magnetization on the layer surface, of which the direction of magnetization is changed according to information; and a reference layer provided against the memory layer, and being a basis of information while having a vertical magnetization on the layer surface, wherein the memory device memorizes the information by reversing the magnetization of the memory layer by a spin torque generated when a current flows between layers made from the memory layer, the nonmagnetization layer and the reference layer, and a coercive force of the memory layer at a memorization temperature is 0.7 times or less than a coercive force at room temperature, and a heat conductivity of a center portion of an electrode formed on one side of the memory layer in the direction of the layer surface is lower than a heat conductivity of surroundings thereof.Type: GrantFiled: July 28, 2011Date of Patent: July 30, 2013Assignee: Sony CorporationInventors: Hiroyuki Ohmori, Masanori Hosomi, Kazuhiro Bessho, Yutaka Higo, Kazutaka Yamane, Hiroyuki Uchida
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Patent number: 8491799Abstract: A method for forming a magnetic tunnel junction cell includes forming a pinning layer, a pinned layer, a dielectric layer and a free layer over a first electrode, forming a second electrode on the free layer, etching the free layer and the dielectric layer using the second electrode as an etch barrier to form a first pattern, forming a prevention layer on a sidewall of the first pattern, and etching the pinned layer and the pinning layer using the second electrode and the prevention layer as an etch barrier to form a second pattern.Type: GrantFiled: June 30, 2008Date of Patent: July 23, 2013Assignee: Hynix Semiconductor Inc.Inventor: Jin-Ki Jung
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Patent number: 8483035Abstract: In a method and an apparatus for inspecting a thermally assisted magnetic recording head element, a specimen is mounted on a table movable in a plane of a scanning probe microscope device, evanescent light is generated from a portion of light emission of evanescent light of the specimen, scattered light of the evanescent light is detected by moving the table in the plane while a cantilever of the scanning probe microscope having a probe is vertically vibrated in the vicinity of a surface of the specimen, and an intensity distribution of the evanescent light emitted from the portion of light emission of evanescent light or a surface profile of the portion of light emission of evanescent light of the specimen is inspected using position information of generation of the evanescent light based on the detected scattered light.Type: GrantFiled: May 29, 2012Date of Patent: July 9, 2013Assignee: Hitachi High-Technologies CorporationInventors: Kaifeng Zhang, Takenori Hirose, Masahiro Watanabe, Shinji Homma, Tsuneo Nakagomi, Teruaki Tokutomi, Toshihiko Nakata, Takehiro Tachizaki
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Patent number: 8482883Abstract: A tunneling magneto-resistive reader includes a sensor stack separating a top magnetic shield from a bottom magnetic shield. The sensor stack includes a reference magnetic element having a reference magnetization orientation direction and a free magnetic element having a free magnetization orientation direction substantially perpendicular to the reference magnetization orientation direction. A non-magnetic spacer layer separates the reference magnetic element from the free magnetic element. A first side magnetic shield and a second side magnetic shield is disposed between the top magnetic shield from a bottom magnetic shield, and the sensor stack is between the first side magnetic shield and the second side magnetic shield. The first side magnetic shield and the second side magnetic shield electrically insulates the top magnetic shield from a bottom magnetic shield.Type: GrantFiled: January 20, 2012Date of Patent: July 9, 2013Assignee: Seagate Technology LLCInventors: Dimitar V. Dimitrov, Zheng Gao, Wonjoon Jung, Paul Edward Anderson, Olle Gunnar Heinonen
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Patent number: 8472150Abstract: A giant magneto-resistive effect device (CPP-GMR device) having the CPP (current perpendicular to plane) structure comprising a spacer layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked one upon another with the spacer layer interposed between them, with a sense current applied in a stacking direction, wherein the spacer layer comprises a first nonmagnetic metal layer and a second nonmagnetic metal layer, each made of a nonmagnetic metal material, and a semiconductor oxide layer interposed between the first nonmagnetic metal layer and the second nonmagnetic metal layer, the semiconductor oxide layer that forms a part of the spacer layer contains zinc oxide as its main component wherein the main component zinc oxide contains an additive metal, and the additive metal is less likely to be oxidized than zinc.Type: GrantFiled: January 3, 2008Date of Patent: June 25, 2013Assignee: TDK CorporationInventors: Yoshihiro Tsuchiya, Tomohito Mizuno, Kei Hirata, Koji Shimazawa, Shinji Hara
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Patent number: 8466524Abstract: Apparatus and associated method for writing data to a non-volatile memory cell, such as spin-torque transfer random access memory (STRAM). In accordance with some embodiments, a resistive sense element (RSE) has a heat assist region, magnetic tunneling junction (MTJ), and pinned region. When a first logical state is written to the MTJ with a spin polarized current, the pinned and heat assist regions each have a substantially zero net magnetic moment. When a second logical state is written to the MTJ with a static magnetic field, the pinned region has a substantially zero net magnetic moment and the heat assist region has a non-zero net magnetic moment.Type: GrantFiled: March 3, 2011Date of Patent: June 18, 2013Assignee: Seagate Technology LLCInventors: Yuankai Zheng, Xiaohua Lou, Haiwen Xi, Michael Xuefei Tang
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Patent number: 8462461Abstract: A spin-torque oscillator (STO) has increased magnetic damping of the oscillating free ferromagnetic layer. The Gilbert magnetic damping parameter (?) is at least 0.05, and preferably greater than 0.05. The free layer may be a any type of conventional ferromagnetic material, but contains one or more damping elements as a dopant. The damping element is selected from the group consisting of Pt, Pd and the 15 lanthanide elements. The free layer damping may also be increased by a damping layer adjacent the free layer. One type of damping layer may be an antiferromagnetic material, like a Mn alloy. As a modification to the antiferromagnetic damping layer, a bilayer damping layer may be formed of the antiferromagnetic layer and a nonmagnetic metal electrically conductive separation layer between the free layer and the antiferromagnetic layer. Another type of damping layer may be one formed of one or more of the elements selected from Pt, Pd and the lanthanides.Type: GrantFiled: July 5, 2011Date of Patent: June 11, 2013Assignee: HGST Netherlands B.V.Inventors: Patrick Mesquita Braganca, Bruce Alvin Gurney
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Patent number: 8456967Abstract: Systems and methods for providing a write pole pedestal for microwave assisted magnetic recording systems are provided. One such system includes a magnetic transducer for microwave assisted magnetic recording, the magnetic transducer including a pole including a leading edge and a trailing edge, a trailing shield positioned closer to the pole trailing edge than the pole leading edge, and an energy transducer positioned between the pole trailing edge and the trailing shield, where a trailing parallel side of the trapezoid is smaller than a leading parallel side of the trapezoid.Type: GrantFiled: October 12, 2011Date of Patent: June 4, 2013Assignee: Western Digital (Fremont), LLCInventor: Michael L. Mallary
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Patent number: 8445979Abstract: A magnetic memory device may include a first vertical magnetic layer, a non-magnetic layer on the first vertical magnetic layer, and a first junction magnetic layer on the non-magnetic layer, with the non-magnetic layer being between the first vertical magnetic layer and the first junction magnetic layer. A tunnel barrier may be on the first junction magnetic layer, with the first junction magnetic layer being between the non-magnetic layer and the tunnel barrier. A second junction magnetic layer may be on the tunnel barrier with the tunnel barrier being between the first and second junction magnetic layers, and a second vertical magnetic layer may be on the second junction magnetic layer with the second junction magnetic layer being between the tunnel barrier and the second vertical magnetic layer.Type: GrantFiled: August 24, 2010Date of Patent: May 21, 2013Assignee: Samsung Electronics Co., Ltd.Inventors: Sechung Oh, Jangeun Lee, Jeahyoung Lee, Woojin Kim, Woo Chang Lim, Junho Jeong, Sukhun Choi
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Patent number: 8441083Abstract: To provide a semiconductor device that has an improved adhesion between a bottom conductive layer and a protection film protecting an MTJ element. This semiconductor device includes a bottom electrode formed over a semiconductor substrate, an MTJ element part formed over a part of the bottom electrode by lamination of a bottom magnetic film, an insulating film, a top magnetic film, and a top electrode in this order, and a protection film formed over the bottom electrode so as to cover the MTJ element part, wherein the bottom electrode is formed by amorphized metal nitride and the protection film is formed by an insulating film containing nitrogen.Type: GrantFiled: April 30, 2012Date of Patent: May 14, 2013Assignee: Renesas Electronics CorporationInventors: Keisuke Tsukamoto, Mikio Tsujiuchi
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Patent number: 8437107Abstract: A magnetic coupling type isolator includes: a magnetic field generator for generating an external magnetic field by an input signal; a magnetoresistive element for detecting the external magnetic field and converting the detected magnetic field into an electric signal, the magnetoresistive element being electrically insulated from the magnetic field generator and positioned in a location capable of being magnetically coupled so as to be overlapped with the magnetic field generator as seen in a top plan view; and first and second shield films overlapped with the magnetic field generator and the magnetoresistive element as seen in a top plan view, wherein a distance between the magnetoresistive element and the second shield film is set to 8 to 100 ?m.Type: GrantFiled: April 5, 2010Date of Patent: May 7, 2013Assignee: Alps Green Devices Co., Ltd.Inventors: Yosuke Ide, Masamichi Saito, Akira Takahashi, Tsuyoshi Nojima, Yoshihiro Nishiyama, Hidekazu Kobayashi, Kenji Ichinohe, Naoki Sakatsume
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Patent number: 8427791Abstract: According to one embodiment, a magnetic head includes a barrier layer having a crystalline structure, a first magnetic layer above the barrier layer, a magnetic insertion layer above the first magnetic layer, and a second magnetic layer above the magnetic insertion layer, the second magnetic layer having a textured face-centered cubic (fcc) structure. The first magnetic layer comprises a high spin polarization magnetic material having a crystalline structure and a characteristic of crystallization being more similar to the crystalline structure of the barrier layer than a crystalline structure of the second magnetic layer and the magnetic insertion layer comprises a magnetic material having a crystalline structure and a characteristic of crystallization being more similar to the crystalline structure of the second magnetic layer than the crystalline structure of the barrier layer. Additional magnetic head structures and methods of producing magnetic heads are described according to more embodiments.Type: GrantFiled: November 23, 2010Date of Patent: April 23, 2013Assignee: HGST Netherlands B.V.Inventors: Zheng Gao, Liubo Hong, Richard Hsiao, Sangmun Oh, Chando Park, Chang-Man Park
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Patent number: 8427790Abstract: A thin film magnetic head includes a magnetoresistive element having a recording-medium-facing-surface which is to be faced with a magnetic recording medium; a magnetic bias layer located on a side opposite to the recording-medium-facing-surface of the magnetoresistive element, and applying a bias magnetic field to the magnetoresistive element in a direction orthogonal to the recording-medium-facing-surface; and a resistive film pattern having the recording-medium-facing-surface, the resistive film pattern being located side by side with the magnetoresistive element in a track-width direction.Type: GrantFiled: June 30, 2008Date of Patent: April 23, 2013Assignee: TDK CorporationInventors: Kei Hirata, Kazuki Sato, Yohei Koyanagi, Takayasu Kanaya, Takeo Kagami
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Patent number: 8416540Abstract: A method and system define a magnetoresistive junction in a magnetic recording transducer. The method and system include performing a first mill at a first angle from a normal to the surface of the magnetic recording transducer. A second mill is performed at a second angle from the normal to the surface. The second angle is larger than the first angle. A third mill is performed at a third angle from the normal to the surface. The third angle is not larger than the first angle.Type: GrantFiled: June 26, 2008Date of Patent: April 9, 2013Assignee: Western Digital (Fremont), LLCInventors: Guanxiong Li, Xiaozhong Dang, Mahendra Pakala, Yong Shen
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Patent number: 8415756Abstract: There are provided a semiconductor device in which short circuit failures in magnetic resistor elements and the like are reduced, and a method of manufacturing the same. An interlayer insulating film in which memory cells are formed is formed such that the upper surface of the portion of the interlayer insulating film located in a memory cell region where the magnetic resistor elements are formed is at a position lower than that of the upper surface of the portion of the interlayer insulating film located in a peripheral region. Another interlayer insulating film is formed so as to cover the magnetic resistor elements. In the another interlayer insulating film, formed are bit lines electrically coupled to the magnetic resistor elements. Immediately below the magnetic resistor elements, formed are digit lines.Type: GrantFiled: August 27, 2010Date of Patent: April 9, 2013Assignee: Renesas Electronics CorporationInventors: Keisuke Tsukamoto, Shinya Hirano, Yuichiro Fujiyama, Tatsunori Murata
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Patent number: 8402635Abstract: A method of manufacturing a magnetic head, including a magneto resistance effect (MR) element that reads a magnetic recording medium, is disclosed. A multilayer film is formed on a shield layer. Unnecessary portions of the multilayer film are removed from both sides of the MR element in a first direction orthogonal to a lamination direction of the multilayer film and parallel to the MR element surface facing the magnetic recording medium. An insulating layer is formed on a surface exposed by removal of the unnecessary portions. An integrated soft magnetic layer covering both sides of the MR element in the first direction and an upper side of the MR element is formed, thereby configuring a second shield layer. An anisotropy application layer is formed on the second shield layer, thereby providing exchange anisotropy to the soft magnetic layer, and magnetizing the soft magnetic layer in a predetermined direction.Type: GrantFiled: March 21, 2011Date of Patent: March 26, 2013Assignee: TDK CorporationInventors: Naomichi Degawa, Takumi Yanagisawa, Satoshi Miura, Yoshikazu Sawada, Takahiko Machita, Kenzo Makino, Takekazu Yamane, Shohei Kawasaki
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Patent number: 8383427Abstract: A semiconductor device having a MTJ device excellent in operating characteristics and a manufacturing method therefor are provided. The MTJ device is formed of a laminated structure which is obtained by laminating a lower magnetic film, a tunnel insulating film, and an upper magnetic film in this order. The lower and upper magnetic films contain noncrystalline or microcrystalline ferrocobalt boron (CoFeB) as a constituent material. The tunnel insulating film contains aluminum oxide (AlOx) as a constituent material. A CAP layer is formed over the upper magnetic film and a hard mask is formed over the CAP layer. The CAP layer contains a substance of crystalline ruthenium (Ru) as a constituent material and the hard mask contains a substance of crystalline tantalum (Ta) as a constituent material. The film thickness of the hard mask is larger than that of the CAP layer.Type: GrantFiled: August 3, 2012Date of Patent: February 26, 2013Assignee: Renesas Electronics CorporationInventors: Ryoji Matsuda, Shuichi Ueno, Haruo Furuta, Takashi Takenaga, Takeharu Kuroiwa
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Patent number: 8385027Abstract: A composite free layer having a FL1/insertion/FL2 configuration is disclosed for achieving high dR/R, low RA, and low ? in TMR or GMR sensors. Ferromagnetic FL1 and FL2 layers have (+) ? and (?) ? values, respectively. FL1 may be CoFe, CoFeB, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, or Nb. FL2 may be CoFe, NiFe, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, Nb, or B. The thin insertion layer includes at least one magnetic element such as Co, Fe, and Ni, and at least one non-magnetic element selected from Ta, Ti, W, Zr, Hf, Nb, Mo, V, Cr, or B. In a TMR stack with a MgO tunnel barrier, dR/R>60%, ?˜1×10?6, and RA=1.2 ohm-um2 when FL1 is CoFe/CoFeB/CoFe, FL2 is CoFe/NiFe/CoFe, and the insertion layer is CoTa or CoFeBTa.Type: GrantFiled: October 19, 2011Date of Patent: February 26, 2013Assignee: Headway Technologies, Inc.Inventors: Tong Zhao, Hui-Chuan Wang, Min Li, Kunliang Zhang
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Patent number: 8385026Abstract: A tunneling magnetoresistance (TMR) device, like a TMR read head for a magnetic recording disk drive, has low magnetic damping, and thus low mag-noise, as a result of the addition of a ferromagnetic backing layer to the ferromagnetic free layer. The backing layer is a material with a low Gilbert damping constant or parameter ?, the well-known dimensionless coefficient in the Landau-Lifshitz-Gilbert equation. The backing layer may have a thickness such that it contributes up to two-thirds of the total moment/area of the combined free layer and backing layer. The backing layer may be formed of a material having a composition selected from (CoxFe(100-x))(100-y)Xy, (Co2Mn)(100-y)Xy and (Co2FexMn(1-x))(100-y)Xy, where X is selected from Ge, Al and Si, and (Co2Fe)(100-y)Aly, where y is in a range that results in a low damping constant for the material.Type: GrantFiled: August 21, 2009Date of Patent: February 26, 2013Assignee: HGST Netherlands B.V.Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
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Patent number: 8379352Abstract: A “thermagnonic” spin-torque oscillator (STO) uses heat flow alone to cause the spin-torque (ST) effect and generate the persistent oscillation of the free layer magnetization. In addition to the conventional free and reference layers, the thermagnonic STO also includes a magnetic oxide layer having a fixed in-plane magnetization, a ferromagnetic metallic layer on one surface of the magnetic oxide layer, a nonmagnetic electrically conductive layer between the free layer and the metallic layer, and an electrically resistive heater on the other surface of the magnetic oxide layer. Due to the thermagnonic effect, heat flow from the magnetic oxide layer through the metallic layer, conductive layer and free layer ultimately results in a spin transfer torque (STT) to the free layer. Electrical sense current flowing in the opposite direction as the heat flow is used to monitor the frequency of oscillation of the free layer magnetization.Type: GrantFiled: September 8, 2011Date of Patent: February 19, 2013Assignee: HGST Netherlands B.V.Inventors: Patrick Mesquita Braganca, Bruce Alvin Gurney
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Patent number: 8375565Abstract: A method fabricates a transducer having an air-bearing surface (ABS). The method includes providing at least one near-field transducer (NFT) film and providing an electronic lapping guide (ELG) film substantially coplanar with a portion of the at least one NFT film. The method also includes defining a disk portion of an NFT from the portion of the at least one NFT film and at least one ELG from the ELG film. The disk portion corresponds to a critical dimension of the NFT from an ABS location. The method also includes lapping the at least one transducer. The lapping is terminated based on a signal from the ELG.Type: GrantFiled: May 28, 2010Date of Patent: February 19, 2013Assignee: Western Digital (Fremont), LLCInventors: Yufeng Hu, Zhongyan Wang, Jinshan Li
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Patent number: 8373948Abstract: A method in one embodiment includes forming a first layer of magnesium above at least one of a free layer and a reference layer; exposing the first layer of magnesium to an oxidizing environment for causing oxidation of the first layer of magnesium; forming a second layer of magnesium above the oxidized first layer of magnesium; and exposing the second layer of magnesium to the oxidizing environment for causing oxidation of the second layer of magnesium. A system in one embodiment includes a free layer; and a tunnel barrier layer having microstructure and composition characteristic of in situ natural oxidation of magnesium. Additional systems and methods are also presented.Type: GrantFiled: April 28, 2008Date of Patent: February 12, 2013Assignee: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Alexander M. Zeltser
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Patent number: 8347487Abstract: A fabricating method of a magnetoresistance sensor is provided with cost effective and process flexibility features. Firstly, a substrate is provided. Then, at least one magnetoresistance structure and at least one bonding pad are formed over the substrate, wherein the bonding pad is electrically connected with the magnetoresistance structure. Then, a passivation layer is formed over the magnetoresistance structure and the bonding pad. Then, a magnetic shielding and concentrator structure is formed over the passivation layer at a location corresponding to the magnetoresistance structure. Finally, bonding pad openings is formed on the passivation layer by patterned polyimide, thereby exposing the bonding pad. After bonding pad was opened, the patterned polyimide can be removed or retained as an additional protection layer.Type: GrantFiled: June 30, 2011Date of Patent: January 8, 2013Assignee: Voltafield Technology CorporationInventors: Fu-Tai Liou, Chih-Chien Liang, Chien-Min Lee
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Patent number: 8345390Abstract: An MR element according to the present invention has the superior effects that further improve an MR ratio because a structure of a spacer layer 40 is configured of a certain three-layer structure with certain materials, and at least one of a first ferromagnetic layer 30 and a second ferromagnetic layer 50 contains a certain amount of an element selected from the group of nitrogen (N), carbon (C), and oxygen (O).Type: GrantFiled: February 26, 2009Date of Patent: January 1, 2013Assignee: TDK CorporationInventors: Yoshihiro Tsuchiya, Shinji Hara, Tsutomu Chou, Hironobu Matsuzawa
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Patent number: 8345389Abstract: A magnetoresistive element includes a first ferromagnetic layer, a second ferromagnetic layer, a nonmagnetic layer, a first metal layer, a second metal layer, a first electrode, and a second electrode. The nonmagnetic layer is provided between the first ferromagnetic layer and the second ferromagnetic layer. The first metal layer includes Au and is provided so that the first ferromagnetic layer is sandwiched between the nonmagnetic layer and the first metal layer. The second metal layer includes a CuNi alloy, and is provided so that the first metal layer is sandwiched between the first ferromagnetic layer and the second metal layer. In addition, magnetization of either one of the first ferromagnetic layer and the second ferromagnetic layer is fixed in a direction. Magnetization of the other is variable in response to an external field. At least one of the first ferromagnetic layer and the second ferromagnetic layer includes a half metal.Type: GrantFiled: September 10, 2010Date of Patent: January 1, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Hiromi Yuasa, Shuichi Murakami, Yoshihiko Fuji, Hideaki Fukuzawa