With Defined Structural Feature Patents (Class 428/811.5)
  • Patent number: 11937512
    Abstract: A semiconductor device including a magnetic tunnel junction stack, a metallic hard mask aligned above the magnetic tunnel junction stack and an air gap surrounding the metallic hard mask. A method including forming a magnetic tunnel junction stack, forming a metallic hard mask aligned above the magnetic tunnel junction stack, conformally forming a dielectric over the metallic hard mask and the magnetic tunnel junction stack, forming barrier on vertical side surfaces of the dielectric, and removing the dielectric between the metallic hard mask and the barrier. A method including forming a magnetic tunnel junction stack, forming a metallic hard mask aligned above the magnetic tunnel junction stack, conformally forming a dielectric over the metallic hard mask and the magnetic tunnel junction stack, selectively removing a portion of the dielectric surrounding the metallic hard mark.
    Type: Grant
    Filed: June 2, 2021
    Date of Patent: March 19, 2024
    Assignee: International Business Machines Corporation
    Inventors: Chandrasekharan Kothandaraman, Nathan P. Marchack, Pouya Hashemi
  • Patent number: 9885764
    Abstract: A high sensitivity push-pull bridge magnetic sensor, wherein the sensor comprises two substrates, magnetoresistive sense elements, push-arm flux concentrators, and pull-arm flux concentrators, wherein the magnetization directions of the pinning layers of the magnetoresistive sense elements on the same substrate are the same, but are opposite to the magnetization directions of the pinning layers of the magnetoresistive sense elements on the adjacent substrate, and the magnetoresistive sense elements on one substrate are electrically interconnected to form a push-arm of the bridge, and the magnetoresistive sense elements on the other substrate are electrically interconnected to form a pull-arm of the bridge. The magnetoresistive sense elements on the push-arm and pull-arm are aligned respectively in the gaps between two adjacent push-arm flux concentrators and two adjacent pull-arm flux concentrators.
    Type: Grant
    Filed: December 24, 2014
    Date of Patent: February 6, 2018
    Assignee: MultiDimension Technology Co., Ltd.
    Inventors: James Geza Deak, Dan Li
  • Patent number: 9269383
    Abstract: According to one embodiment, a magnetic head includes a lower magnetic shield positioned at a media facing surface of the head, a lower sensor positioned above the lower magnetic shield, the lower sensor including a lower free layer, a middle magnetic shield positioned above the lower sensor at the media facing surface of the head, and a back side antiferromagnetic (AFM) layer positioned behind the lower free layer in an element height direction, the back side AFM layer being configured to provide magnetic stabilization for the middle magnetic shield. In another embodiment, a method includes forming a lower sensor including a lower free layer, forming a back side AFM layer behind the lower free layer in an element height direction, and forming a middle magnetic shield above the lower sensor, wherein the back side AFM layer is configured to provide magnetic stabilization for the middle magnetic shield.
    Type: Grant
    Filed: January 23, 2015
    Date of Patent: February 23, 2016
    Assignee: HGST Netherlands B.V.
    Inventors: Masashi Hattori, Kouichi Nishioka, Takashi Wagatsuma, Nobuo Yoshida, Kenichi Meguro
  • Patent number: 9202482
    Abstract: A magnetic sensor having a novel pinning structure resulting in a greatly reduced gap spacing. The sensor has a magnetic free layer structure that extends to a first stripe height and a magnetic pinned layer structure that extends to a second stripe height that is longer than the first stripe high. A layer of anti-ferromagnetic material is formed over the pinned layer structure in the region beyond the first stripe height location. In this way, the antiferromagnetic layer is between the pinned layer and the second or upper shield and does not contribute to gap spacing.
    Type: Grant
    Filed: August 27, 2013
    Date of Patent: December 1, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Quang Le, Simon H. Liao, Guangli Liu, Kochan Ju, Youfeng Zheng
  • Patent number: 9040178
    Abstract: A TMR sensor that includes a free layer having at least one B-containing (BC) layer made of CoFeB, CoFeBM, CoB, COBM, or CoBLM, and a plurality of non-B containing (NBC) layers made of CoFe, CoFeM, or CoFeLM is disclosed where L and M are one of Ni, Ta, Ti, W, Zr, Hf, Tb, or Nb. One embodiment is represented by (NBC/BC)n where n?2. A second embodiment is represented by (NBC/BC)n/NBC where n?1. In every embodiment, a NBC layer contacts the tunnel barrier and NBC layers each with a thickness from 2 to 8 Angstroms are formed in alternating fashion with one or more BC layers each 10 to 80 Angstroms thick. Total free layer thickness is <100 Angstroms. The free layer configuration described herein enables a significant noise reduction (SNR enhancement) while realizing a high TMR ratio, low magnetostriction, low RA, and low Hc values.
    Type: Grant
    Filed: September 22, 2008
    Date of Patent: May 26, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Hui-Chuan Wang, Yu-Chen Zhou, Min Li, Kunliang Zhang
  • Patent number: 9036308
    Abstract: Various embodiments may be generally directed to a magnetic sensor constructed with a decoupling layer that has a predetermined first morphology. A magnetic free layer can be deposited contactingly adjacent to the decoupling layer with the magnetic free layer configured to have at least a first sub-layer having a predetermined second morphology.
    Type: Grant
    Filed: September 21, 2011
    Date of Patent: May 19, 2015
    Assignee: Seagate Technology LLC
    Inventors: Mark William Covington, Mark Thomas Kief, Wonjoon Jung
  • Patent number: 9034491
    Abstract: A magnetic element may generally be configured at least with a magnetic stack having a multilayer barrier structure disposed between first and second ferromagnetic layers. The multilayer barrier structure can have a binary compound layer disposed between first and second alloy layers with the binary compound having a metal element and a second element where at least one alloy layer has the metal element and a third element dissimilar from the second element.
    Type: Grant
    Filed: November 30, 2012
    Date of Patent: May 19, 2015
    Assignee: Seagate Technology LLC
    Inventors: Vijay Karthik Sankar, Mark William Covington
  • Patent number: 9017832
    Abstract: Various embodiments may be generally directed to a magnetic element capable of optimized magnetoresistive data reading. Such a magnetic element may be configured at least with a magnetoresistive stack that has an electrode lamination having at least a transition metal layer disposed between a magnetically free layer of the magnetoresistive stack and an electrode layer of the electrode lamination.
    Type: Grant
    Filed: January 31, 2013
    Date of Patent: April 28, 2015
    Assignee: Seagate Technology LLC
    Inventors: Eric Walter Singleton, Liwen Tan, Jae-Young Yi
  • Patent number: 9007728
    Abstract: A method comprises providing a magnetic element including a free layer, a pinned layer, a nonmagnetic spacer layer between the free and pinned layers, and a pinning layer adjacent the pinned layer. The free layer is biased in a first direction. The pinned layer has a first layer having a first magnetization, a second layer having a second magnetization, and a nonmagnetic layer between the first and second layer. The first magnetization is pinned parallel to a second direction substantially perpendicular to the first direction and substantially perpendicular to the ABS. The second magnetization is antiparallel to the second direction. The pinning layer is oriented along the second direction. The method further comprises providing a hard bias structure having a hard bias magnetization, initializing the hard bias magnetization along the second direction, performing at least one thermal treatment, and resetting the hard bias magnetization substantially along the first direction.
    Type: Grant
    Filed: June 26, 2012
    Date of Patent: April 14, 2015
    Assignee: Western Digital (Fremont), LLC
    Inventors: Feng Liu, Prakash Mani, Christian Kaiser, Laurence L. Chen
  • Patent number: 8945730
    Abstract: A storage element including: a storage layer; a magnetization fixed layer; and an insulating layer, wherein by injecting spin-polarized electrons in a laminating direction of a layered structure that includes the storage layer, the insulating layer, and the magnetization fixed layer, the orientation of magnetization of the storage layer changes and recording of information is performed on the storage layer, and an Fe film and a film that includes Ni are formed in order from an interface side that is in contact with the insulating layer, and a graded composition distribution of Ni and Fe is formed after heating on at least one of the storage layer and the magnetization fixed layer.
    Type: Grant
    Filed: December 5, 2011
    Date of Patent: February 3, 2015
    Assignee: Sony Corporation
    Inventors: Hiroyuki Ohmori, Masanori Hosomi, Kazuhiro Bessho, Yutaka Higo, Kazutaka Yamane, Hiroyuki Uchida, Tetsuya Asayama
  • Patent number: 8947835
    Abstract: The invention provides a tunneling magnetoresistance (TMR) read sensor with a long diffusion path and ex-situ interfaces in a sense layer structure. The sense layer structure comprises a first sense layer preferably formed of a ferromagnetic Co—Fe film, a second sense layer preferably formed of a ferromagnetic Co—Fe—B film, and a third sense layer preferably formed of a ferromagnetic Ni—Fe film. The sense layer structure has a long diffusion path (defined as a total thickness of the first and second sense layers) and ex-situ interfaces for suppressing unwanted diffusions of Ni atoms. Alternatively, the sense layer structure comprises a first sense layer preferably formed of a ferromagnetic Co—Fe film, a second sense layer preferably formed of a ferromagnetic Co—Fe—B film, a third sense layer preferably formed of a ferromagnetic Co—Fe—B—Hf film, and a fourth sense layer preferably formed of a ferromagnetic Ni—Fe film.
    Type: Grant
    Filed: December 22, 2011
    Date of Patent: February 3, 2015
    Assignee: HGST Netherlands B.V.
    Inventor: Tsann Lin
  • Patent number: 8946834
    Abstract: A CoFeB or CoFeNiB magnetic layer wherein the boron content is 25 to 40 atomic % and with a thickness <20 Angstroms is used to achieve high perpendicular magnetic anisotropy and enhanced thermal stability in magnetic devices. A dusting layer made of Co, Ni, Fe or alloy thereof is added to top and bottom surfaces of the CoFeB layer to increase magnetoresistance as well as improve Hc and Hk. Another embodiment includes a non-magnetic metal insertion in the CoFeB free layer. The CoFeB layer with elevated B content may be incorporated as a free layer, dipole layer, or reference layer in STT-MRAM memory elements or in spintronic devices including a spin transfer oscillator. Thermal stability is increased such that substantial Hk is retained after annealing to at least 400° C. for 1 hour. Ku enhancement is achieved and the retention time of a memory cell for STT-MRAM designs is increased.
    Type: Grant
    Filed: March 1, 2012
    Date of Patent: February 3, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Yu-Jen Wang, Witold Kula, Guenole Jan
  • Patent number: 8895162
    Abstract: A magnetoresistive element according to an embodiment includes: a base layer; a first magnetic layer formed on the base layer and having a changeable magnetization direction with an easy axis of magnetization in a direction perpendicular to a film plane; a first nonmagnetic layer formed on the first magnetic layer; and a second magnetic layer formed on the first nonmagnetic layer and having a fixed magnetization layer with an easy axis of magnetization in a direction perpendicular to the film plane. The first magnetic layer includes a ferrimagnetic layer having a DO22 structure or an L10 structure, the ferrimagnetic layer has a c-axis oriented in a direction perpendicular to the film plane, and the magnetization direction of the first magnetic layer is changeable by a current flowing through the first magnetic layer, the first nonmagnetic layer, and the second magnetic layer.
    Type: Grant
    Filed: September 19, 2011
    Date of Patent: November 25, 2014
    Assignees: Kabushiki Kaisha Toshiba, National University Corporation Tohoku University
    Inventors: Katsuya Nishiyama, Shigemi Mizukami, Terunobu Miyazaki, Hiroaki Yoda, Tadashi Kai, Tatsuya Kishi, Daisuke Watanabe, Mikihiko Oogane, Yasuo Ando, Masatoshi Yoshikawa, Toshihiko Nagase, Eiji Kitagawa, Tadaomi Daibou, Makoto Nagamine, Chunlan Feng
  • Patent number: 8871365
    Abstract: Enhanced Hc and Hk in addition to higher thermal stability to 400° C. are achieved in magnetic devices by adding dusting layers on top and bottom surfaces of a spacer in a synthetic antiferromagnetic (SAF) structure to give a RL1/DL1/spacer/DL2/RL2 reference layer configuration where RL1 and RL2 layers exhibit perpendicular magnetic anisotropy (PMA), the spacer induces antiferromagnetic coupling between RL1 and RL2, and DL1 and DL2 are dusting layers that enhance PMA. RL1 and RL2 layers are selected from laminates such as (Ni/Co)n, L10 alloys, or rare earth-transition metal alloys. The reference layer may be incorporated in STT-MRAM memory elements or in spintronic devices including a spin transfer oscillator. Dusting layers and a similar SAF design may be employed in a free layer for Ku enhancement and to increase the retention time of a memory cell.
    Type: Grant
    Filed: February 28, 2012
    Date of Patent: October 28, 2014
    Assignee: Headway Technologies, Inc.
    Inventors: Yu-Jen Wang, Witold Kula, Ru Ying Tong, Guenole Jan
  • Patent number: 8852760
    Abstract: A boron or boron containing dusting layer such as CoB or FeB is formed along one or both of top and bottom surfaces of a free layer at interfaces with a tunnel barrier layer and capping layer to improve thermal stability while maintaining other magnetic properties of a MTJ stack. Each dusting layer has a thickness from 0.2 to 20 Angstroms and may be used as deposited, or at temperatures up to 400° C. or higher, or following a subsequent anneal at 400° C. or higher. The free layer may be a single layer of CoFe, Co, CoFeB or CoFeNiB, or may include a non-magnetic insertion layer. The resulting MTJ is suitable for STT-MRAM memory elements or spintronic devices. Perpendicular magnetic anisotropy is maintained in the free layer at temperatures up to 400° C. or higher. Ku enhancement is achieved and the retention time of a memory cell for STT-MRAM designs is increased.
    Type: Grant
    Filed: April 17, 2012
    Date of Patent: October 7, 2014
    Assignee: Headway Technologies, Inc.
    Inventors: Yu-Jen Wang, Witold Kula, Ru-Ying Tong, Guenole Jan
  • Patent number: 8830735
    Abstract: A magnetic memory includes: a magnetization fixed layer having perpendicular magnetic anisotropy, a magnetization direction of the magnetization fixed layer being fixed; an interlayer dielectric; an underlayer formed on upper faces of the magnetization fixed layer and the interlayer dielectric; and a data recording layer formed on an upper face of the underlayer and having perpendicular magnetic anisotropy. The underlayer includes: a first magnetic underlayer; and a non-magnetic underlayer formed on the first magnetic underlayer. The first magnetic underlayer is formed with such a thickness that the first magnetic underlayer does not exhibit in-plane magnetic anisotropy in a portion of the first magnetic underlayer formed on the interlayer dielectric.
    Type: Grant
    Filed: November 23, 2011
    Date of Patent: September 9, 2014
    Assignee: Renesas Electronics Corporation
    Inventors: Eiji Kariyada, Katsumi Suemitsu, Hironobu Tanigawa, Kaoru Mori, Tetsuhiro Suzuki, Kiyokazu Nagahara, Yasuaki Ozaki, Norikazu Ohshima
  • Patent number: 8822046
    Abstract: A stack having a seed layer structure with a first part having a first cross-track width and a free layer deposited over the seed layer structure and with a second cross-track width, wherein the first cross-track width is greater than the second cross-track width. In one implementation, the seed layer structure further comprises an antiferromagnetic (AFM) layer and a synthetic antiferromagnetic (SAF) layer. In one alternate implementation, the cross-track width of the seed layer structure is substantially equal to the combined cross-track width of the free layer and cross-track width of two permanent magnets.
    Type: Grant
    Filed: April 30, 2012
    Date of Patent: September 2, 2014
    Assignee: Seagate Technology LLC
    Inventors: Eric Walter Singleton, Jae-Young Yi, Konstantin Nikolaev, Victor Boris Sapozhnikov, Stacey Christine Wakeham, Shaun Eric McKinlay
  • 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: 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: 8758909
    Abstract: A magnetoresistive element that includes a free ferromagnetic layer comprising a reversible magnetization directed substantially perpendicular to a film surface, a pinned ferromagnetic layer comprising a fixed magnetization directed substantially perpendicular to the film surface, and a tunnel barrier layer disposed between the free and pinned ferromagnetic layers, wherein the free and pinned layers contain at least one element selected from the group consisting of Fe, Co, and Ni, at least one element selected from the group consisting of V, Cr, and Mo, and at least one element selected from the group consisting of B, P, C, and Si, and wherein the free layer, the tunnel barrier layer, and the pinned layer have a coherent body-centered cubic 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 a magnetization direction of the free layer.
    Type: Grant
    Filed: April 20, 2012
    Date of Patent: June 24, 2014
    Inventor: Alexander Mikhailovich Shukh
  • Patent number: 8709617
    Abstract: In accordance with one aspect of the invention, a magnetic memory element records information in a spin valve structure having a free layer, a pinning layer, and a nonmagnetic layer sandwiched therebetween. The magnetic memory element further has, on the free layer, a separate nonmagnetic layer and a magnetic change layer having magnetic characteristics which change according to temperature. Multiple cutouts, including one cutout with a different shape, are provided in a peripheral portion of the spin valve structure. A method of driving the magnetic memory element is characterized in that information is recorded by applying unipolar electric pulses.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: April 29, 2014
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Yasushi Ogimoto, Haruo Kawakami
  • Patent number: 8687321
    Abstract: A magnetic head assembly includes: a magnetic recording head, a head slider, a suspension and an actuator arm. The magnetic recording head includes a spin torque oscillator and a main magnetic pole. The spin torque oscillator includes, a first magnetic layer including at least one selected from the group consisting of a Fe—Co—Al alloy, a Fe—Co—Si alloy, a Fe—Co—Ge alloy, a Fe—Co—Mn alloy a Fe—Co—Cr alloy and a Fe—Co—B alloy, a second magnetic layer, and an intermediate layer provided between the first magnetic layer and the second magnetic layer. The main magnetic pole is placed together with the spin torque oscillator. The magnetic recording head is mounted on the head slider. The head slider is mounted on one end of the suspension. The actuator arm is connected to other end of the suspension.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: April 1, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kenichiro Yamada, Hitoshi Iwasaki, Masayuki Takagishi, Tomomi Funayama
  • Patent number: 8679653
    Abstract: A spin-valve element has a pair of ferromagnetic layers having mutually different coercive forces, sandwiching an insulating layer or a nonmagnetic layer therebetween. The in-plane shape of the spin-valve element is substantially circular in shape but is provided, in the peripheral portion, with a plurality of cutouts NS, NW, NE, NN. Preferably, the shape of at least one cutout be made different from that of others. Moreover, a storage device that employs such a spin-valve element is provided.
    Type: Grant
    Filed: September 5, 2008
    Date of Patent: March 25, 2014
    Assignee: Fuji Electric Co., Ltd.
    Inventors: Haruo Kawakami, Yasushi Ogimoto
  • Patent number: 8637170
    Abstract: A magnetic sensor comprises a support; a nonmagnetic conductive layer disposed on the support; a fixed magnetization layer disposed on a first part of the nonmagnetic conductive layer and on the support; a free magnetization layer disposed on a second part of the nonmagnetic conductive layer different from the first part and on the support; and a nonmagnetic low resistance layer, disposed on a part overlapping the nonmagnetic conductive layer in at least one of the fixed magnetization layer and free magnetization layer, having an electrical resistivity lower than that of the one layer.
    Type: Grant
    Filed: May 26, 2009
    Date of Patent: January 28, 2014
    Assignee: TDK Corporation
    Inventor: Tomoyuki Sasaki
  • 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: 8586216
    Abstract: A large spin-polarized current can be provided. A single crystal MgO layer is grown on an Si single crystal substrate, being lattice-matched. Thereon, a ferromagnetic metal layer is grown. Growth plane of MgO layer formed on (100) plane of Si single crystal substrate is (100) plane. At interface between Si single crystal substrate and MgO layer, Si (100) [110] and MgO (100) [100] directions are parallel. FIG. 2(A) shows Si (100) plane, FIG. 2(B) MgO (100) plane, and FIG. 2(C) the state of these two planes being lattice-matched. Si (100) plane in FIG. 2(A) is constituted by Si atoms 111 alone, while MgO (100) plane in FIG. 2(B) is constituted by Mg atoms 121 and oxygen (O) atoms 122. MgO (100) plane is grown on Si (100) plane, and as shown in FIG. 2(C), Si (100) [110] and MgO (100) [100] directions are parallel at the interface.
    Type: Grant
    Filed: December 13, 2011
    Date of Patent: November 19, 2013
    Assignees: Akita Prefecture, TDK Corporation
    Inventor: Toshio Suzuki
  • Patent number: 8582249
    Abstract: A magnetic element has a magnetically responsive lamination with a ferromagnetic free layer separated from a synthetic antiferromagnetic (SAF) layer by a spacer layer and from a sensed data bit stored in an adjacent medium by an air bearing surface (ABS). The lamination is coupled to at least one antiferromagnetic (AFM) tab a predetermined offset distance from the ABS.
    Type: Grant
    Filed: April 26, 2011
    Date of Patent: November 12, 2013
    Assignee: Seagate Technology LLC
    Inventors: Victor Boris Sapozhnikov, Eric Walter Singleton, Mark William Covington
  • Patent number: 8563147
    Abstract: 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: Grant
    Filed: June 24, 2009
    Date of Patent: October 22, 2013
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yuchen Zhou, Min Zheng
  • Patent number: 8557407
    Abstract: 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: Grant
    Filed: August 6, 2010
    Date of Patent: October 15, 2013
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Kunliang Zhang, Hui Chuan Wang, Yu-Hsia Chen, Min Li
  • Patent number: 8551626
    Abstract: 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: Grant
    Filed: June 25, 2009
    Date of Patent: October 8, 2013
    Assignee: Seagate Technology LLC
    Inventors: Qing He, Yonghua Chen, Juren Ding
  • Patent number: 8545999
    Abstract: 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: Grant
    Filed: February 21, 2008
    Date of Patent: October 1, 2013
    Assignee: Western Digital (Fremont), LLC
    Inventors: Qunwen Leng, Mahendra Pakala, Yong Shen
  • Patent number: 8518562
    Abstract: 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: Grant
    Filed: November 12, 2009
    Date of Patent: August 27, 2013
    Assignee: Renesas Electronics Corporation
    Inventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Takada, Ryoji Matsuda, Yosuke Takeuchi
  • Patent number: 8507113
    Abstract: The present invention is directed to align crystal c-axes in magnetic layers near two opposed junction wall surfaces of a magnetoresistive element so as to be almost perpendicular to the junction wall surfaces. A magnetic sensor stack body has, on sides of opposed junction wall surfaces of a magnetoresistive element, field regions for applying a bias magnetic field to the element. The field region has first and second magnetic layers having magnetic particles having crystal c-axes, the first magnetic layer is disposed adjacent to the junction wall surface in the field region, the crystal c-axes in the first magnetic layer are aligned and oriented along an ABS in a film plane, the second magnetic layer is disposed adjacent to the first magnetic layer in the field region, and the crystal c-axis directions in the second magnetic layer are distributed at random in a plane.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: August 13, 2013
    Assignee: Canon Anelva Corporation
    Inventors: Einstein Noel Abarra, Tetsuya Endo
  • Patent number: 8456898
    Abstract: Techniques and magnetic devices associated with a magnetic element that includes a fixed layer having a fixed layer magnetization and perpendicular anisotropy, a nonmagnetic spacer layer, and a free layer having a changeable free layer magnetization and perpendicular anisotropy.
    Type: Grant
    Filed: December 5, 2011
    Date of Patent: June 4, 2013
    Assignee: Grandis Inc.
    Inventors: Eugene Youjun Chen, Shengyuan Wang
  • Patent number: 8440330
    Abstract: Magnetic tunnel junction cells and methods of making magnetic tunnel junction cells that include a radially protective layer extending proximate at least the ferromagnetic free layer of the cell. The radially protective layer can be specifically chosen in thickness, deposition method, material composition, and/or extent along the cell layers to enhance the effective magnetic properties of the free layer, including the effective coercivity, effective magnetic anisotropy, effective dispersion in magnetic moment, or effective spin polarization.
    Type: Grant
    Filed: October 21, 2011
    Date of Patent: May 14, 2013
    Assignee: Seagate Technology, LLC
    Inventors: Paul E. Anderson, Song S. Xue
  • Patent number: 8431255
    Abstract: Embodiments of the present invention relate to a galvanomagnetic device for use as a magnetic sensor or magnetic memory device. In a particular embodiment, the galvanomagnetic device comprises a non-conductive substrate, a first magnetic layer having a magnetic anisotropy perpendicular to the surface thereof, and a ferromagnetic second magnetic layer formed on the first magnetic layer. On the second magnetic layer, current electrodes are disposed to pass a current between two points, and voltage electrodes are disposed to detect a Hall voltage between two points perpendicularly to the current flow direction.
    Type: Grant
    Filed: December 24, 2008
    Date of Patent: April 30, 2013
    Assignee: HGST Netherlands BV
    Inventors: Das Sarbanoo, Hiroyuki Suzuki, Takayoshi Ohtsu
  • Patent number: 8406040
    Abstract: A magnetic tunnel junction stack including a pinned magnetic layer, a tunnel barrier layer formed of magnesium oxide (MgO), a free magnetic layer adjacent to the tunnel barrier layer, and a layer of vanadium (V) adjacent to the free magnetic layer.
    Type: Grant
    Filed: January 8, 2010
    Date of Patent: March 26, 2013
    Assignee: International Business Machines Corporation
    Inventors: Daniel C. Worledge, Guohan Hu, Jonathan Z. Sun
  • Patent number: 8400738
    Abstract: An apparatus and associated method may be used to provide a data sensing element capable of detecting changes in magnetic states. Various embodiments of the present invention are generally directed to a magnetically responsive lamination of layers and [a] means for generating a high magnetic moment region proximal to an air bearing surface (ABS) and a low magnetic moment region proximal to a hard magnet.
    Type: Grant
    Filed: April 25, 2011
    Date of Patent: March 19, 2013
    Assignee: Seagate Technology LLC
    Inventors: Mark William Covington, Qing He, Thomas Roy Boonstra
  • Patent number: 8379429
    Abstract: A domain wall motion element has a magnetic recording layer 10 that is formed of a ferromagnetic film and has a domain wall DW. The magnetic recording layer 10 has: a pair of end regions 11-1 and 11-2 whose magnetization directions are fixed; and a center region 12 sandwiched between the pair of end regions 11-1 and 11-2, in which the domain wall. DW moves. A first trapping site TS1 by which the domain wall DW is trapped is formed at a boundary between the end region 11-1, 11-2 and the center region 12. Furthermore, at least one second trapping site TS2 by which the domain wall DW is trapped is formed within the center region 12.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: February 19, 2013
    Assignee: NEC Corporation
    Inventors: Nobuyuki Ishiwata, Tetsuhiro Suzuki, Norikazu Ohshima, Kiyokazu Nagahara, Shunsuke Fukami
  • Patent number: 8338004
    Abstract: The present invention provides a magnetic tunnel junction structure, including a first magnetic layer having a fixed magnetization direction and a second magnetic layer having a reversible magnetization direction. A non-magnetic layer is formed between the first magnetic layer and the second magnetic layer and a third magnetic layer allows the magnetization direction of the second magnetic layer to be inclined with respect to a plane of the second magnetic layer by a magnetic coupling to the second magnetic layer with a vertical magnetic anisotropic energy thereof larger than a horizontal magnetic anisotropic energy thereof. A crystal-structure separation layer is formed between the second magnetic layer and the third magnetic layer for separating a crystal orientation between the second and the third magnetic layers.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: December 25, 2012
    Assignee: Korea Institute of Science and Technology
    Inventors: Kyung Ho Shin, Byoung Chul Min
  • Patent number: 8288023
    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: December 23, 2010
    Date of Patent: October 16, 2012
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Haiwen Xi
  • Patent number: 8274811
    Abstract: A spin transfer oscillator (STO) structure is disclosed that includes two assist layers with perpendicular magnetic anisotropy (PMA) to enable a field generation layer (FGL) to achieve an oscillation state at lower current density for MAMR applications. In one embodiment, the STO is formed between a main pole and write shield and the FGL has a synthetic anti-ferromagnetic structure. The STO configuration may be represented by seed layer/spin injection layer (SIL)/spacer/PMA layer 1/FGL/spacer/PMA layer 2/capping layer. The spacer may be Cu for giant magnetoresistive (GMR) devices or a metal oxide for tunneling magnetoresistive (TMR) devices. Alternatively, the FGL is a single ferromagnetic layer and the second PMA assist layer has a synthetic structure including two PMA layers with magnetic moment in opposite directions in a seed layer/SIL/spacer/PMA assist 1/FGL/spacer/PMA assist 2/capping layer configuration. SIL and PMA assist layers are laminates of (CoFe/Ni)x or the like.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: September 25, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yuchen Zhou
  • Patent number: 8240025
    Abstract: Provided is a method and apparatus to manufacture a thermally-assisted magnetic recording head in which a light source unit including a light source and a slider including an optical system are joined. The method comprises steps of: adhering by suction the light source unit with a back holding jig; bringing the light into contact with a slider back surface; applying a load to a load application surface of the light source unit by a loading means to bring a joining surface of the light source unit into conformity with the slider back surface; positioning the light source unit apart from the slider, and then aligning the light source with the optical system; bringing again the light source unit into contact with the slider; and applying a load again to the load application surface.
    Type: Grant
    Filed: September 23, 2010
    Date of Patent: August 14, 2012
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Seiichi Takayama, Nobuyuki Mori, Yoshihiro Tsuchiya, Shinji Hara
  • Patent number: 8216703
    Abstract: A magnetic tunnel junction (MTJ) (10) employing a dielectric tunneling barrier (16), useful in magnetoresistive random access memories (MRAMs) and other devices, has a synthetic antiferromagnet (SAF) structure (14, 16), comprising two ferromagnetic (FM) layers (26, 41; 51, 58; 61, 68) separated by a coupling layer (38, 56, 66). Improved magnetoresistance (MR) ratio is obtained by providing a further layer (44, 46, 46?, 47, 52, 62), e.g. containing Ta, preferably spaced apart from the coupling layer (38, 56, 66) by a FM layer (41, 30-2, 54). The further layer (44, 46, 46?, 47, 52, 62) may be a Ta dusting layer (44) covered by a FM layer (30-2), or a Ta containing FM alloyed layer (46), or a stack (46?) of interleaved FM and N-FM layers, or other combination (47, 62). Furthering these benefits, another FM layer, e.g., CoFe, NiFe, (30, 30-1, 51, 61) is desirably provided between the further layer (44, 46, 46?, 47, 52, 62) and the tunneling barrier (16).
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: July 10, 2012
    Assignee: Everspin Technologies, Inc.
    Inventors: Jijun Sun, Jon M. Slaughter
  • Patent number: 8197953
    Abstract: A magnetic stack having a free layer having a switchable magnetization orientation, a reference layer having a pinned magnetization orientation, and a barrier layer therebetween. The stack includes an annular antiferromagnetic pinning layer electrically isolated from the free layer and in physical contact with the reference layer. In some embodiments, the reference layer is larger than the free layer.
    Type: Grant
    Filed: April 11, 2011
    Date of Patent: June 12, 2012
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Antoine Khoueir, Brian Lee, Pat Ryan, Michael Tang, Insik Jin, Paul E. Anderson
  • Patent number: 8194361
    Abstract: It is made possible to provide a spin-torque oscillator that has a high Q value and a high output. A spin-torque oscillator includes: an oscillating field generating unit configured to generate an oscillating field; and a magnetoresistive element including a magnetoresistive effect film including a first magnetization pinned layer of which a magnetization direction is pinned, a first magnetization free layer of which a magnetization direction oscillates with the oscillating field, and a first spacer layer interposed between the first magnetization pinned layer and the first magnetization free layer.
    Type: Grant
    Filed: September 29, 2008
    Date of Patent: June 5, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Kiwamu Kudo, Tazumi Nagasawa, Koichi Mizushima, Rie Sato
  • Patent number: 8169753
    Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with ferromagnetic amorphous buffer and polycrystalline seed layers is disclosed for reducing a read gap, in order to perform magnetic recording at higher linear densities. The ferromagnetic amorphous buffer and polycrystalline seed layers couples to a ferromagnetic lower shield, thus acting as part of the ferromagnetic lower shield and defining the upper surface of the ferromagnetic polycrystalline seed layer as the lower bound of the read gap. In addition, a CPP TMR or GMR read sensor with nonmagnetic and ferromagnetic cap layers is also disclosed for reducing the read gap, in order to perform magnetic recording at even higher linear densities. The ferromagnetic cap layer couples to a ferromagnetic upper shield, thus acting as part of the ferromagnetic upper shield and defining the lower surface of the ferromagnetic cap layer as the upper bound of the read gap.
    Type: Grant
    Filed: November 21, 2008
    Date of Patent: May 1, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Tsann Lin
  • Patent number: 8147994
    Abstract: A layered structure includes an amorphous Ta layer, a metallic oxide layer formed from zinc oxide (ZnO) or magnesium oxide (MgO) on the Ta layer, and a FePt magnetic layer formed on the metallic oxide layer. Therefore, an L10 structural FePt ordered alloy is obtained at a temperature of 300° C. or lower.
    Type: Grant
    Filed: February 26, 2009
    Date of Patent: April 3, 2012
    Assignee: TDK Corporation
    Inventors: Hironobu Matsuzawa, Tsutomu Chou
  • Patent number: 8124253
    Abstract: A tunneling magnetic sensing element includes a laminate in which an underlayer, a seed layer, an antiferromagnetic layer, a pinned magnetic layer, an insulating barrier layer, and a free magnetic layer are laminated in order from below. The insulating barrier layer is made of Mg—O. The underlayer is made of Ti, and the seed layer is made of one selected from a group consisting of Ni—Fe—Cr and Ru.
    Type: Grant
    Filed: November 10, 2009
    Date of Patent: February 28, 2012
    Assignee: ALPS Electric Co., Ltd.
    Inventors: Kazumasa Nishimura, Masamichi Saito, Yosuke Ide, Ryo Nakabayashi, Yoshihiro Nishiyama, Hidekazu Kobayashi, Naoya Hasegawa
  • Patent number: 8072800
    Abstract: Techniques and magnetic devices associated with a magnetic element that includes a fixed layer having a fixed layer magnetization and perpendicular anisotropy, a nonmagnetic spacer layer, and a free layer having a changeable free layer magnetization and perpendicular anisotropy.
    Type: Grant
    Filed: September 15, 2009
    Date of Patent: December 6, 2011
    Assignee: Grandis Inc.
    Inventors: Eugene Youjun Chen, Shengyuan Wang