Having Tunnel Junction Effect Patents (Class 360/324.2)
  • Patent number: 8852762
    Abstract: A synthetic antiferromagnetic device includes a reference layer having a first and second ruthenium layer, a magnesium oxide spacer layer disposed on the reference layer, a cobalt iron boron layer disposed on the magnesium oxide spacer layer and a third ruthenium layer disposed on the cobalt iron boron layer, the third ruthenium layer having a thickness of approximately 0 angstroms to 18 angstroms.
    Type: Grant
    Filed: July 31, 2012
    Date of Patent: October 7, 2014
    Assignee: International Business Machines Corporation
    Inventors: David W. Abraham, Michael C. Gaidis, Janusz J. Nowak, Daniel C. Worledge
  • Patent number: 8841006
    Abstract: The present invention relates to a magnetic tunnel junction device and a manufacturing method thereof. The magnetic tunnel junction device includes: i) a first magnetic layer including a compound having a chemical formula of (A100-xBx)100-yCy; ii) an insulating layer deposited on the first magnetic layer; and iii) a second magnetic layer deposited on the insulating layer and including a compound having a chemical formula of (A100-xBx)100-yCy. The first and second magnetic layers have perpendicular magnetic anisotropy, A and B are respectively metal elements, and C is at least one amorphizing element selected from a group consisting of boron (B), carbon (C), tantalum (Ta), and hafnium (Hf).
    Type: Grant
    Filed: February 16, 2010
    Date of Patent: September 23, 2014
    Assignee: Korea Institute of Science and Technology
    Inventors: Gyung-Min Choi, Byoung Chul Min, Kyung Ho Shin
  • Patent number: 8836058
    Abstract: A magnetic device includes a first electrode portion, a free layer portion arranged on the first electrode portion, the free layer portion including a magnetic insulating material, a reference layer portion contacting the free layer portion, the reference layer portion including a magnetic metallic layer, and a second electrode portion arranged on the reference layer portion.
    Type: Grant
    Filed: November 29, 2012
    Date of Patent: September 16, 2014
    Assignee: International Business Machines Corporation
    Inventors: Marcin J. Gajek, Daniel C. Worledge
  • Patent number: 8837092
    Abstract: An apparatus can be generally directed to a magnetic stack having a magnetically free layer positioned on an air bearing surface (ABS). The magnetically free layer can be biased to a predetermined magnetization in various embodiments by a biasing structure that is coupled with the magnetically free layer and positioned distal the ABS.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: September 16, 2014
    Assignee: Seagate Technology LLC
    Inventors: Mark William Covington, Dimitar Velikov Dimitrov, Dian Song
  • Patent number: 8836057
    Abstract: Magnetoresistive elements, and memory devices including the same, include a pinned layer having a fixed magnetization direction, a free layer corresponding to the pinned layer, and a protruding element protruding from the free layer and having a changeable magnetization direction. The free layer has a changeable magnetization direction. The protruding element is shaped in the form of a tube. The protruding element includes a first protruding portion and a second protruding portion protruding from ends of the free layer facing in different directions.
    Type: Grant
    Filed: October 31, 2012
    Date of Patent: September 16, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sung-chul Lee, Ung-hwan Pi, Kwang-seok Kim, Kee-won Kim, Young-man Jang
  • Patent number: 8836060
    Abstract: The present disclosure provides a spin device including: a graphene; a first ferromagnetic electrode and a second electrode that are in electrical contact with and sandwich the graphene; a third ferromagnetic electrode and a fourth electrode that sandwich the graphene at a position apart from the first and second electrodes in electrical contact with the graphene; a current applying portion that applies an electric current between the first ferromagnetic electrode and the second electrode; and a voltage-signal detecting portion that detects spin accumulation information as a voltage signal via the third ferromagnetic electrode and the fourth electrode. The spin accumulation information is generated, by application of the electric current, in a part of the graphene that is sandwiched between the third and fourth electrodes. The first and third ferromagnetic electrodes are disposed on the same surface of the graphene, and the second and fourth electrodes are non-magnetic or ferromagnetic electrodes.
    Type: Grant
    Filed: February 28, 2013
    Date of Patent: September 16, 2014
    Assignee: Panasonic Corporation
    Inventors: Akihiro Odagawa, Nozomu Matsukawa
  • Patent number: 8830616
    Abstract: A write head for a magnetic storage device includes a writing tip comprising a magnetic material, a write pulse generator configured to generate a write pulse signal comprising a varying voltage bias between the magnetic storage device and the writing tip. The write pulse signal comprising one or more write pulses effective to tunnel electrons from the writing tip to the magnetic storage device. The data stream generator configured to provide a data stream signal to the writing tip where the data stream signal is operative to vary spin polarity in the electrons from a first polarity to a second polarity.
    Type: Grant
    Filed: December 4, 2012
    Date of Patent: September 9, 2014
    Assignee: Varian Semiconductor Equipment Associates, Inc.
    Inventors: Frank Sinclair, Alexander C. Kontos, Rajesh Dorai
  • Patent number: 8823119
    Abstract: A magnetic body structure including: a magnetic layer pattern; and a conductive pattern including a metallic glass alloy and covering at least a portion of the magnetic body structure.
    Type: Grant
    Filed: November 21, 2012
    Date of Patent: September 2, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Ki-joon Kim, Hyung-joon Kwon
  • Patent number: 8810973
    Abstract: A magnetoresistive sensor having employing a Mn containing Huesler alloy for improved magnetoresistive performance in a structure that minimizes corrosion and Mn migration. The sensor can be constructed with a pinned layer structure that includes a lamination of layers of Co2MnX and CoFe, where X is Al, Ge or Si. The Co2MnX can be sandwiched between the layers of CoFe to prevent Mn migration into the spacer/barrier layer. The free layer can also be constructed as a lamination of Co2MnX and CoFe layers, and may also be constructed so that the Co2MnX layer is sandwiched between CoFe layers to prevent Mn migration.
    Type: Grant
    Filed: May 13, 2008
    Date of Patent: August 19, 2014
    Assignee: HGST Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 8809978
    Abstract: A memory element includes a layered structure: a memory layer having a changeable magnetization direction, the magnetization direction being changed by applying a current in a lamination direction of the layered structure to record the information in the memory layer, including a first ferromagnetic layer having a magnetization direction that is inclined from a direction perpendicular to a film face, a bonding layer laminated on the first ferromagnetic layer, and a second ferromagnetic layer laminated on the bonding layer and bonded to the first ferromagnetic layer via the bonding layer, having a magnetization direction that is inclined from the direction perpendicular to the film face, a magnetization-fixed layer having a fixed magnetization direction, an intermediate layer that is provided between the memory layer and the magnetization-fixed layer, and is contacted with the first ferromagnetic layer, and a cap layer that is contacted with the second ferromagnetic layer.
    Type: Grant
    Filed: November 13, 2012
    Date of Patent: August 19, 2014
    Assignee: Sony Corporation
    Inventors: Yutaka Higo, Masanori Hosomi, Hiroyuki Ohmori, Kazuhiro Bessho, Tetsuya Asayama, Kazutaka Yamane, Hiroyuki Uchida
  • Patent number: 8790798
    Abstract: A magnetoresistive element (and method of fabricating the magnetoresistive element) that includes a free ferromagnetic layer comprising a first reversible magnetization direction directed substantially perpendicular to a film surface, a pinned ferromagnetic layer comprising a second fixed magnetization direction directed substantially perpendicular to the film surface, and a nonmagnetic insulating tunnel barrier layer disposed between the free ferromagnetic layer and the pinned ferromagnetic layer, wherein the free ferromagnetic layer, the tunnel barrier layer, and the pinned ferromagnetic layer have a coherent body-centered cubic (bcc) structure with a (001) plane oriented, and a bidirectional spin-polarized current passing through the coherent structure in a direction perpendicular to the film surface reverses the magnetization direction of the free ferromagnetic layer.
    Type: Grant
    Filed: April 12, 2012
    Date of Patent: July 29, 2014
    Inventor: Alexander Mikhailovich Shukh
  • Patent number: 8791535
    Abstract: 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?atan(?)) degrees.
    Type: Grant
    Filed: August 19, 2013
    Date of Patent: July 29, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Yoshiaki Asao
  • Patent number: 8778515
    Abstract: Embodiments of the present invention provide a practical magneto-resistive effect element for CPP-GMR, which exhibits appropriate resistance-area-product and high magnetoresistance change ratio, and meets the demand for a narrow read gap. Certain embodiments of a magneto-resistive effect element in accordance with the present invention include a pinned ferromagnetic layer containing a first ferromagnetic film having a magnetization direction fixed in one direction, a free ferromagnetic layer containing a second ferromagnetic film having a magnetization direction varying in response to an external magnetic field, an intermediate layer provided between the pinned ferromagnetic layer and the free ferromagnetic layer, and a current confinement layer for confining a current. At least one of the pinned ferromagnetic layer or the free ferromagnetic layer includes a highly spin polarized layer.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: July 15, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Yo Sato, Katsumi Hoshino, Hiroyuki Hoshiya
  • Patent number: 8765490
    Abstract: The present disclosure describes a semiconductor MRAM device and a manufacturing method. The device reduces magnetic field induction “interference” (disturbance) phenomenon between adjacent magnetic tunnel junctions when data is written and read. This semiconductor MRAM device comprises a magnetic tunnel junction unit and a magnetic shielding material layer covering the sidewalls of the magnetic tunnel junction unit. The method for manufacturing a semiconductor device comprises: forming a magnetic tunnel junction unit, depositing an isolation dielectric layer to cover the top and the sidewall of the magnetic tunnel junction unit, and depositing a magnetic shielding material layer on the isolation dielectric layer.
    Type: Grant
    Filed: October 17, 2012
    Date of Patent: July 1, 2014
    Assignees: Semiconductor Manufacturing International (Shanghai) Corporation, Semiconductor Manufacturing International (Beijing) Corporation
    Inventor: Gavin Zeng
  • Patent number: 8767356
    Abstract: An MR sensor includes a first shielding layer, a second shielding layer, an MR element formed therebetween, and a pair of hard magnet layers respectively placed on two sides of the MR element. The MR element includes an AFM layer formed on the first shielding layer, a pinned layer formed on the AFM layer and a free layer formed between the pinned layer and the second shielding layer. The free layer is funnel-shaped, which has a first edge facing an air bearing surface and a second edge opposite the first edge, and the first edge has a narrower width than that of the second edge. The MR sensor can improve MR height control performance, and improve the ESD performance and decrease the PCN and RTN and, in turn, get a more stable performance. The present invention also discloses a magnetic head, an HGA and a disk drive unit.
    Type: Grant
    Filed: June 11, 2010
    Date of Patent: July 1, 2014
    Assignees: SAE Magnetics (H.K.) Ltd., TDK Corporation
    Inventors: Chiuming Leung, Kosuke Tanaka, Kazuki Sato, Cheukwing Leung, Juren Ding, Rongkwang Ni, Wanyin Kwan, Mankit Lee
  • Patent number: 8758850
    Abstract: A spin transfer torque 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: Grant
    Filed: September 21, 2011
    Date of Patent: June 24, 2014
    Assignee: Avalanche Technology, Inc.
    Inventors: Yuchen Zhou, Yiming Huai
  • Patent number: 8753899
    Abstract: A method includes patterning a plurality of magnetic tunnel junction (MTJ) layers to form an MTJ cell, and forming a dielectric cap layer over a top surface and on a sidewall of the MTJ cell. The step of patterning and the step of forming the dielectric cap layer are in-situ formed in a same vacuum environment. A plasma treatment is performed on the dielectric cap layer to transform the dielectric cap layer into a treated dielectric cap layer, whereby the treated dielectric cap layer improves protection from H2O or O2, and thus degradation.
    Type: Grant
    Filed: August 23, 2011
    Date of Patent: June 17, 2014
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Bang-Tai Tang, Cheng-Yuan Tsai
  • Patent number: 8743511
    Abstract: A method and apparatus for increasing the electrical resistivity and corrosion resistance of the material forming a spacer layer in current-perpendicular-to-the-plane (CPP) giant magnetoresistive (GMR) sensors. The increased resistivity of the spacer layer, and thus, the CPP-GMR sensor permits a larger voltage across the sensor and a higher signal-to-noise ratio. The increased corrosion resistance of the spacer layer minimizes the effects of exposing the spacer layer to corrosive materials during fabrication. For example, adding tin to silver to form a metallic alloy spacer layer increases the corrosion resistance of the spacer layer and the electrical resisitivity of the CPP-GMR sensor relative to a spacer layer consisting solely of silver. The Ag—Sn alloy permits a larger current to flow through the sensor, which increases the signal-to-noise ratio.
    Type: Grant
    Filed: August 31, 2011
    Date of Patent: June 3, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Jeffrey R. Childress, John C. Read, Neil Smith
  • Patent number: 8729647
    Abstract: A thermally stable Magnetic Tunnel Junction (MTJ) cell, and a memory device including the same, include a pinned layer having a pinned magnetization direction, a separation layer on the pinned layer, and a free layer on the separation layer and having a variable magnetization direction. The pinned layer and the free layer include a magnetic material having Perpendicular Magnetic Anisotropy (PMA). The free layer may include a central part and a marginal part on a periphery of the central part. The free layer is shaped in the form of a protrusion in which the central part is thicker than the marginal part.
    Type: Grant
    Filed: November 20, 2012
    Date of Patent: May 20, 2014
    Assignee: Samsung Electronics., Ltd.
    Inventors: Sung-chul Lee, Kwang-seok Kim, Kee-won Kim, Young-man Jang, Ung-hwan Pi
  • Patent number: 8726491
    Abstract: 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: Grant
    Filed: November 4, 2011
    Date of Patent: May 20, 2014
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 8722211
    Abstract: A magnetic memory device may include a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer arranged on a substrate. The tunnel barrier layer may include a crystal structure and may be arranged between the first ferromagnetic layer and the second ferromagnetic layer. At least the first ferromagnetic layer may include a first layer in contact with the tunnel barrier layer and a second layer in contact with the first layer, and an orientation of the first layer with respect to the tunnel barrier layer may be greater than an orientation of the second layer with respect to the tunnel barrier layer.
    Type: Grant
    Filed: January 19, 2010
    Date of Patent: May 13, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Woojin Kim, Jangeun Lee, Sechung Oh, KyungTae Nam, Dae Kyom Kim, Junho Jeong
  • Patent number: 8717715
    Abstract: A spin accumulation magnetic sensor having improved signal strength and efficiency. The spin accumulation magnetic sensor has a detector structure and a spin injection structure and has a non-magnetic, electrically conductive layer extending between the spin injection structure and the detector structure. The detector structure has first and second free layers arranged such that the non-magnetic, electrically conductive layer extends between them and so that they are magnetically anti-parallel coupled with one another. The spin injection structure can also include first and second magnetic layers with the electrically conductive layer extending between them and with the first magnetic layer being pinned and the second magnetic layer being anti-parallel coupled with the first magnetic layer.
    Type: Grant
    Filed: December 13, 2012
    Date of Patent: May 6, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Daisuke Sato, Masaki Yamada
  • Patent number: 8710604
    Abstract: In accordance with an embodiment, a magnetoresistive element includes a lower electrode, a first magnetic layer on the lower electrode, a first diffusion prevention layer on the first magnetic layer, a first interfacial magnetic layer on the first metal layer, a nonmagnetic layer on the first interfacial magnetic layer, a second interfacial magnetic layer on the nonmagnetic layer, a second diffusion prevention layer on the second interfacial magnetic layer, a second magnetic layer on the second diffusion prevention layer, and an upper electrode layer on the second magnetic layer. The ratio of a crystal-oriented part to the other part in the second interfacial magnetic layer is higher than the ratio of a crystal-oriented part to the other part in the first interfacial magnetic layer.
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: April 29, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Yamakawa, Katsuaki Natori, Daisuke Ikeno, Tadashi Kai
  • Patent number: 8701274
    Abstract: A manner for stabilizing the shield domain structure is described that employs the magnetic field of a hard bias layer. More particularly, it has been found that the shield domain structure is stabilized when the height of the hard bias layer in the depth direction is made substantially half the height of upper shield layer. In another embodiment of the invention, a stabilizing structure is provided at approximately the midpoint of the shield in order to fix the closure domain of the shield to the desired two-domain structure. In an embodiment of the invention, the stabilizing structure is made convex or concave as viewed from the air-bearing surface.
    Type: Grant
    Filed: December 30, 2011
    Date of Patent: April 22, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Koji Kataoka, Takashi Wagatsuma
  • Patent number: 8705213
    Abstract: A disclosed device having a principle axis and including a magnetoresistive stack, the magnetoresistive stack having first and second opposing surfaces, the magnetoresistive stack including a free layer, a spacer layer, and a reference layer, wherein the spacer layer is positioned between the first and reference layer, the free layer includes magnetic material having a free magnetic orientation in a first plane; the spacer layer includes nonmagnetic material; and the reference layer includes magnetic material having a pinned magnetic orientation in a second plane, wherein the second plane is perpendicular to the first plane and parallel to the principle axis of the device; an insulating layer at least a portion of the outer surface of the magnetoresistive stack; a shielding layer surrounding at least a portion of the insulating layer; and a conducting layer, wherein the conducting layer provides electrical connection between the magnetoresistive stack and the shielding layer.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: April 22, 2014
    Assignee: Seagate Technology LLC
    Inventors: William Hill Butler, Dimitar V. Dimitrov
  • Patent number: 8689430
    Abstract: A method and system for providing a perpendicular magnetic recording (PMR) head are disclosed. A PMR pole having a bottom and a top wider than the bottom is provided. The PMR pole may be formed by depositing a PMR pole layer, then removing part of the PMR pole layer, leaving the PMR pole. The PMR pole may also be provided by forming a trench having the desired profile in a photoresist layer, depositing the PMR pole layer, then removing the photoresist layer, leaving the PMR pole in the location of the trench. A side gap is deposited over the PMR pole. A side shield is provided on the side gap. A planarization that removes part of the side shield on the PMR pole is performed. A top gap is provided on the PMR pole, substantially covering the entire PMR pole. A top shield is provided on the top gap.
    Type: Grant
    Filed: November 29, 2006
    Date of Patent: April 8, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Yingjian Chen, Kyusik Sin
  • Patent number: 8686524
    Abstract: A magnetic stack having a ferromagnetic free layer, a metal oxide layer that is antiferromagnetic at a first temperature and non-magnetic at a second temperature higher than the first temperature, a ferromagnetic pinned reference layer, and a non-magnetic spacer layer between the free layer and the reference layer. During a writing process, the metal oxide layer is non-magnetic. For magnetic memory cells, such as magnetic tunnel junction cells, the metal oxide layer provides reduced switching currents.
    Type: Grant
    Filed: June 8, 2012
    Date of Patent: April 1, 2014
    Assignee: Seagate Technology LLC
    Inventors: Xiaohua Lou, Yuankai Zheng, Wenzhong Zhu, Wei Tian, Zheng Gao
  • Patent number: 8679577
    Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.
    Type: Grant
    Filed: September 12, 2012
    Date of Patent: March 25, 2014
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Haiwen Xi
  • Patent number: 8677607
    Abstract: The method according to the present invention includes the steps of: sequentially applying a plurality of different voltages to an MR element and sequentially detecting output signals from the MR element; and eliminating the MR element as a defective product when an evaluation value, based on a difference of SN ratios of the output signals from the MR element respectively obtained for each applied voltage, is less than a threshold value, and selecting the MR element as a non-defective product when the evaluation value is greater than or equal to the threshold value.
    Type: Grant
    Filed: March 7, 2008
    Date of Patent: March 25, 2014
    Assignee: TDK Corporation
    Inventors: Takumi Yanagisawa, Masaru Hirose, Shunji Saruki
  • Patent number: 8671554
    Abstract: An example method for manufacturing a magneto-resistance effect element having a magnetic layer, a free magnetization layer, and a spacer layer includes forming a first metallic layer and forming, on the first metallic layer, a second metallic layer. A first conversion treatment is performed to convert the second metallic layer into a first insulating layer and to form a first metallic portion penetrating through the first insulating layer. A third metallic layer is formed on the first insulating layer and the first metallic portion. A second conversion treatment is performed to convert the third metallic layer into a second insulating layer and to form a second metallic portion penetrating through the second insulating layer.
    Type: Grant
    Filed: March 13, 2012
    Date of Patent: March 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Yoshihiko Fuji
  • Patent number: 8674465
    Abstract: A semiconductor device includes a magnetic tunnel junction (MTJ) storage element configured to be disposed in a common interlayer metal dielectric (IMD) layer with a logic element. Cap layers separate the common IMD layer from a top and bottom IMD layer. Top and bottom electrodes are coupled to the MTJ storage element. Metal connections to the electrodes are formed in the top and bottom IMD layers respectively through vias in the separating cap layers. Alternatively, the separating cap layers are recessed and the bottom electrodes are embedded, such that direct contact to metal connections in the bottom IMD layer is established. Metal connections to the top electrode in the common IMD layer are enabled by isolating the metal connections from the MTJ storage elements with metal islands and isolating caps.
    Type: Grant
    Filed: August 5, 2010
    Date of Patent: March 18, 2014
    Assignee: QUALCOMM Incorporated
    Inventors: Xia Li, Xiaochun Zhu, Seung H. Kang
  • Patent number: 8670218
    Abstract: A hard magnet biasing structure for a CPP-GMR or CPP-TMR read head for a magnetic recording disk drive is located between the two sensor shields and abutting the side edges of the sensor free layer. The biasing structure includes a crystalline MgO insulating layer on the lower shield and the side edges of the free layer, a seed layer of either Ir or Ru on and in contact with the MgO layer, a layer of at least partially chemically-ordered ferromagnetic FePt alloy hard bias layer on the seed layer, and a capping layer on the FePt alloy hard bias layer. The MgO layer may be a single layer on and in contact with the side edges of the free layer, or an upper layer on and in contact with a base insulating layer selected from an aluminum oxide, a tantalum oxide, a titanium oxide, and a silicon nitride.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: March 11, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Alexander M. Zeltser, Stefan Maat, Ning Shi
  • Patent number: 8670216
    Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor has a reference layer formed as an exchange-coupled structure. The exchange-coupled structure includes a patterned layer formed of alternating stripes of ferromagnetic stripes and nonmagnetic stripes, and a continuous unpatterned ferromagnetic layer in contact with and exchange-coupled to the ferromagnetic stripes of the patterned layer. The ferromagnetic stripes have a length-to-width aspect ratio of at least 2, which results in increased uniaxial anisotropy of the exchange-coupled ferromagnetic layer.
    Type: Grant
    Filed: February 11, 2013
    Date of Patent: March 11, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jeffrey R. Childress, Yang Li, Neil Smith
  • Patent number: 8670217
    Abstract: A scissoring-type CPP-MR sensor has the two free ferromagnetic layers formed as exchange-coupled structures. Each exchange-coupled structure includes a patterned layer formed of alternating stripes of ferromagnetic stripes and nonmagnetic stripes, and a continuous unpatterned ferromagnetic layer in contact with and exchange-coupled to the ferromagnetic stripes of the patterned layer. The ferromagnetic stripes have a length-to-width aspect ratio of at least 2, which results in increased uniaxial anisotropy of the exchange-coupled unpatterned ferromagnetic layer. The stripes are oriented at an acute angle relative to the disk-facing surface of the sensor, and the stripes of the first free layer are generally orthogonal to the stripes of the second free layers. A hard magnet layer is magnetized in a direction orthogonal to the disk-facing surface for biasing the magnetization directions of the unpatterned ferromagnetic layers in the first and second free layers generally orthogonal to one another.
    Type: Grant
    Filed: February 11, 2013
    Date of Patent: March 11, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jeffrey R. Childress, Yang Li, Neil Smith
  • Patent number: 8659103
    Abstract: According to one embodiment, a magnetoresistive element includes the following configuration. A first magnetic layer has an invariable magnetization. A second magnetic layer has a variable magnetization. A nonmagnetic layer is provided between the first and the second magnetic layers. The first magnetic layer has a structure in which first, second and third magnetic material films and a nonmagnetic material film are stacked. The first magnetic material film is provided in contact with the nonmagnetic layer, the nonmagnetic material film is provided in contact with the first magnetic material film, the second magnetic material film is provided in contact with the nonmagnetic material film, and the third magnetic material film is provided in contact with the second magnetic material film. The second magnetic material film has a Co concentration higher than that of the first magnetic material film.
    Type: Grant
    Filed: March 19, 2012
    Date of Patent: February 25, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Daisuke Watanabe, Katsuya Nishiyama, Toshihiko Nagase, Koji Ueda, Tadashi Kai
  • Patent number: 8653824
    Abstract: A method for quasi-static testing a magnetic recording head read sensor is described. The method includes applying a first voltage to a heater in the magnetic recording head and measuring an output of the magnetic recording head read sensor while applying the first voltage to the heater and recording the measured output as a first set of measurements. The method further includes applying a second voltage to the heater in the magnetic recording head and measuring the output of the magnetic recording head read sensor while applying the second voltage to the heater and recording the measured output as a second set of measurements. The first and second sets of measurements are then compared.
    Type: Grant
    Filed: December 16, 2009
    Date of Patent: February 18, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Feng Liu, Mehran Zargari
  • Patent number: 8638530
    Abstract: A current-perpendicular-to-the-plane magnetoresistive sensor structure includes at least an improved top shield structure and optionally also a similar bottom shield structure. The top shield structure includes an antiparallel structure (APS) of two ferromagnetic films and a nonmagnetic antiparallel coupling (APC) film between them. The APC film induces antiferromagnetic (AF) coupling between the two ferromagnetic films so that they have their respective magnetizations oriented antiparallel. An important aspect of the APS is that there is no antiferromagnetic layer adjacent the upper ferromagnetic film, so that the upper ferromagnetic film does not have its magnetization pinned by an antiferromagnetic layer. An electroplated shield layer is formed above the APS.
    Type: Grant
    Filed: February 20, 2013
    Date of Patent: January 28, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Yimin Hsu, Stefan Maat, Arley Cleveland Marley, Alexander M. Zeltser
  • Patent number: 8637947
    Abstract: A memory element includes a layered structure and a negative thermal expansion material layer. The layered structure includes a memory layer, a magnetization-fixed layer, and an intermediate layer. The memory layer has magnetization perpendicular to a film face in which a magnetization direction is changed depending on information, and includes a magnetic layer having a positive magnetostriction constant. The magnetization direction is changed by applying a current in a lamination direction of the layered structure to record the information in the memory layer. The magnetization-fixed layer has magnetization perpendicular to a film face that becomes a base of the information stored in the memory layer. The intermediate layer is formed of a non-magnetic material and is provided between the memory layer and the magnetization-fixed layer.
    Type: Grant
    Filed: November 26, 2012
    Date of Patent: January 28, 2014
    Assignee: Sony Corporation
    Inventors: Kazutaka Yamane, Masanori Hosomi, Hiroyuki Ohmori, Kazuhiro Bessho, Yutaka Higo, Tetsuya Asayama, Hiroyuki Uchida
  • Patent number: 8625237
    Abstract: A magnetic reproduction head includes a lower magnetic shield layer, an upper magnetic shield layer, a magnetoresistive film formed between the lower and the upper magnetic shield layers, a refill film in an element height direction disposed in contact with a surface opposite a floating surface of the magnetoresistive film, and a refill film in a track width direction disposed on a side wall surface of the magnetoresistive film. The magnetoresistive film is a tunneling magnetoresistive film including a free layer, an insulating barrier layer, and a fixed layer. The insulating barrier layer is one of a magnesium oxide film, an aluminum oxide film, and a titanium oxide film which contains at least one of nitrogen and silicon.
    Type: Grant
    Filed: November 17, 2008
    Date of Patent: January 7, 2014
    Assignee: Hitachi, Ltd.
    Inventor: Tomio Iwasaki
  • Patent number: 8615868
    Abstract: A method for manufacturing a magnetic sensor that includes depositing a plurality of mask layers, then forming a stripe height defining mask over the sensor layers. A first ion milling is performed just sufficiently to remove portions of the free layer that are not protected by the stripe height defining mask, the first ion milling being terminated at the non-magnetic barrier or spacer layer. A dielectric layer is then deposited, preferably by ion beam deposition. A second ion milling is then performed to remove portions of the pinned layer structure that are not protected by the mask, the free layer being protected during the second ion milling by the dielectric layer.
    Type: Grant
    Filed: November 29, 2011
    Date of Patent: December 31, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Yongchul Ahn, Xiaozhong Dang, Quang Le, Simon H. Liao
  • Patent number: 8607438
    Abstract: A read sensor for a transducer is fabricated. The transducer has a field region and a sensor region corresponding to the sensor. A sensor stack is deposited. A hybrid mask including hard and field masks is provided. The hard mask includes a sensor portion covering the sensor region and a field portion covering the field region. The field mask covers the field portion of the hard mask. The field mask exposes the sensor portion of the hard mask and part of the sensor stack between the sensor and field regions. The sensor is defined from the sensor stack in a track width direction. Hard bias layer(s) are deposited. Part of the hard bias layer(s) resides on the field mask. Part of the hard bias layer(s) adjoining the sensor region is sealed. The field mask is lifted off. The transducer is planarized.
    Type: Grant
    Filed: December 1, 2011
    Date of Patent: December 17, 2013
    Assignee: Western Digital (Fremont), LLC
    Inventors: Wei Gao, Guanxiong Li, Ming Mao, Chih-Ching Hu, Guanghong Luo, Miao Wang, Zhihong Zhang, Anup G. Roy
  • Patent number: 8611055
    Abstract: A method of producing a magnetoresistive read head and a tunneling magnetoresistive read head produced thereby are disclosed. A shield layer is provided. A magnetic etch-stop layer is formed over the shield layer, where the magnetic etch-stop layer comprises a nonmagnetic metal and a soft magnetic material with overall property still being magnetically soft. A sensor stack is formed over the magnetic etch-stop layer. A patterned mask layer is formed over the sensor stack. Material from a portion of the sensor stack not covered by the patterned mask is removed.
    Type: Grant
    Filed: July 31, 2009
    Date of Patent: December 17, 2013
    Assignee: Western Digital (Fremont), LLC
    Inventors: Mahendra Pakala, Rongfu Xiao, Chando Park
  • Patent number: 8604573
    Abstract: According to one embodiment, a semiconductor memory device includes plural magneto-resistance elements. In the semiconductor memory device, each of the magneto-resistance elements includes: a first magnetic layer formed on a semiconductor substrate, the first magnetic layer having an easy axis of magnetization perpendicular to a film surface thereof; a non-magnetic layer formed on the first magnetic layer; a second magnetic layer formed on the non-magnetic layer, the second magnetic layer having an easy axis of magnetization perpendicular to a film surface thereof; and a sidewall film provided so as to cover a sidewall of each of the magneto-resistance elements with a protective film interposed therebetween, the sidewall film providing a tensile stress to the magneto-resistance element along the easy axis of magnetization.
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: December 10, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Yamakawa, Katsuaki Natori, Daisuke Ikeno, Yasuyuki Sonoda
  • Patent number: 8593766
    Abstract: A magneto-resistive effect (MR) element includes first and second magnetic layers in which a relative angle formed by magnetization directions changes responsive to an external magnetic field, and a spacer layer positioned between the first and second magnetic layers. The first magnetic layer is positioned closer to a substrate above which the MR element is formed than the second magnetic layer. The spacer layer includes copper and metal intermediate layers and a main spacer layer composed primarily of gallium oxide. The copper and metal intermediate layers are positioned between the main spacer and first magnetic layers. The metal intermediate layer is positioned between the copper and main spacer layers. The metal intermediate layer is composed primarily of at least one from a group of one of magnesium and at least partially oxidized magnesium, and one of aluminum and at least partially oxidized aluminum.
    Type: Grant
    Filed: February 22, 2011
    Date of Patent: November 26, 2013
    Assignee: TDK Corporation
    Inventors: Yoshihiro Tsuchiya, Tsutomu Chou, Hironobu Matsuzawa, Hayato Koike
  • Patent number: 8592930
    Abstract: A magnetic memory element includes: a first magnetization free layer; a non-magnetic layer; a reference layer; a first magnetization fixed layer group; and a first blocking layer. The first magnetization free layer is composed of ferromagnetic material with perpendicular magnetic anisotropy and includes a first magnetization fixed region, a second magnetization fixed region and a magnetization free region. The non-magnetic layer is provided near the first magnetization free layer. The reference layer is composed of ferromagnetic material and provided on the non-magnetic layer. The first magnetization fixed layer group is provided near the first magnetization fixed region. The first blocking layer is provided being sandwiched between the first magnetization fixed layer group and the first magnetization fixed region or in the first magnetization fixed layer group.
    Type: Grant
    Filed: October 21, 2010
    Date of Patent: November 26, 2013
    Assignee: NEC Corporation
    Inventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Norikazu Ohshima, Nobuyuki Ishiwata
  • Patent number: 8592929
    Abstract: A spin transfer torque magnetic random access memory (STT-MRAM) device includes magnetic tunnel junctions (MTJs) with reduced switching current asymmetry. At least one switching asymmetry balance layer (SABL) near the free layer of the MTJ reduces a first switching current Ic(p-ap) causing the value of the first switching current to be nearly equal to the value of a second switching current Ic(ap-p) without increasing the average switching current of the device. The SABL may be a non-magnetic switching asymmetry balance layer (NM-SABL) and/or a magnetic switching asymmetry balance layer (M-SABL).
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: November 26, 2013
    Assignee: QUALCOMM Incorporated
    Inventors: Wei-Chuan Chen, Kangho Lee, Xiaochun Zhu, Seung H. Kang
  • Patent number: 8582252
    Abstract: A magnetic sensor includes a magnetic layer comprising magnetic material and a grain refining agent. The magnetic layer having a grain-refined magnetic layer surface. A layer adjacent the magnetic layer has a layer surface that conforms to the grain-refined magnetic layer surface.
    Type: Grant
    Filed: November 2, 2005
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventors: Brian William Karr, Eric Walter Singleton, Qing He
  • Patent number: 8582253
    Abstract: A magnetic sensor configured to reside in proximity to a recording medium during use having a high spin polarization reference layer stack above AFM layers. The reference layer stack comprises a first boron-free ferromagnetic layer above the AFM coupling layer; a magnetic coupling layer on and in contact with the first boron-free ferromagnetic layer; a second ferromagnetic layer comprising boron deposited on and contact with the magnetic coupling layer; and a boron-free third ferromagnetic layer on and in contact the second ferromagnetic layer. A barrier layer is deposited on and in contact with the boron-free third ferromagnetic layer. In one aspect of the invention, the magnetic coupling layer may comprise at least one of Ta, Ti, or Hf. A process for providing the magnetic sensor is also provided.
    Type: Grant
    Filed: June 4, 2012
    Date of Patent: November 12, 2013
    Assignee: Western Digital (Fremont), LLC
    Inventors: Yuankai Zheng, Qunwen Leng, Mahendra Pakala, Zhitao Diao, Christian Kaiser, Cheng-Han Yang
  • Patent number: 8576519
    Abstract: A current-perpendicular-to-the-plane magnetoresistive sensor has magnetic damping material located adjacent either or both of the sensor side edges and back edge to reduce the effect of spin transfer torque. The damping material may be Pt, Pd, Os, or a rare earth metal from the 15 lanthanoid elements. The damping material may be an ultrathin layer in contact with the sensor edges. An insulating layer is deposited on the damping layer and isolates the sensor's ferromagnetic biasing layer from the damping layer. Instead of being a separate layer, the damping material may be formed adjacent the sensor edges by being incorporated into the material of the insulating layer.
    Type: Grant
    Filed: October 11, 2012
    Date of Patent: November 5, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Young-suk Choi, John Creighton Read
  • Patent number: 8576518
    Abstract: 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: Grant
    Filed: October 30, 2012
    Date of Patent: November 5, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Alexander M. Zeltser, Stefan Maat