Detail Of Free Layer Or Additional Film For Affecting Or Biasing The Free Layer Patents (Class 360/324.12)
  • Patent number: 7869166
    Abstract: A thin film magnetic head has: a spin valve having a pinned layer whose having a fixed magnetization direction, a first nonmagnetic intermediate layer disposed on the pinned layer, and a free layer having a variable magnetization direction, the free layer disposed on the first nonmagnetic intermediate layer; and bias magnetic layers for applying a bias magnetic field to the free layer provided on both sides of the spin valve. The pinned layer has a hard magnetic layer, a second nonmagnetic intermediate layer disposed on the hard magnetic layer, and a ferromagnetic layer disposed on the second nonmagnetic intermediate layer. The bias magnetic layer has a bias antiferromagnetic layer, and a bias ferromagnetic layer disposed on the bias antiferromagnetic layer. A height direction dimension of the pinned layer is longer than a track width direction dimension, and longer than a height direction dimension of the free layer.
    Type: Grant
    Filed: February 20, 2007
    Date of Patent: January 11, 2011
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Shinji Hara, Takahiko Machita
  • Publication number: 20100328799
    Abstract: A spin torque oscillation magnetoresistive sensor for measuring a magnetic field. The sensor uses a change in precessional oscillation frequency of a magnetization of a magnetic layer to determine the magnitude of a magnetic field. The sensor can include a magnetic free layer, a magnetic pinned layer and a non-magnetic layer sandwiched therebetween. Circuitry is connected with these layers to induce an electrical current through the layers. Spin polarization of electrons traveling through the device causes a spin torque induced precession of the magnetization of one or more of the layers. The frequency of this oscillation modulates in response to a magnetic field. The modulation of the oscillation frequency can be measured to detect the presence of the magnetic field, and determine its magnitude.
    Type: Application
    Filed: June 25, 2009
    Publication date: December 30, 2010
    Inventors: Patrick Mesquita Braganca, Bruce Alvin Gurney, Bruce Alexander Wilson
  • Publication number: 20100328823
    Abstract: A magnetic reader comprises first and second shields oriented transversely to a media-facing surface, a magnetoresistive stack located between the first and second shields, and a flux guide. The magnetoresistive stack extends from a proximal end oriented toward the media-facing surface to a distal end oriented away from the media-facing surface. The flux guide extends from the first shield toward the second shield, and is spaced from the magnetoresistive stack at the distal end. The flux guide magnetically couples the distal end of the magnetoresistive stack to the first shield.
    Type: Application
    Filed: June 25, 2009
    Publication date: December 30, 2010
    Applicant: SEAGATE TECHNOLOGY LLC
    Inventors: Yonghua Chen, Jiaoming Qiu, Xilin Peng, Kaizhong Gao
  • Patent number: 7848065
    Abstract: A magnetoresistive sensor having magnetically anisotropic bias layers for biasing the free layer of the sensor. Hard bias structures for biasing the magnetization of the free layer are formed at either side of the sensor stack, and each of the hard bias structure includes a hard magnetic layer that has a magnetic anisotropy to enhance the stability of the biasing. The hard bias structure can include a Cr under-layer having a surface that has been treated by a low power angled ion milling to form it with an anisotropic surface texture. A layer of Cr—Mo alloy is formed over the Cr under-layer and the hard magnetic material layer is formed over the Cr—Mo alloy layer. The anisotropic surface texture of the Cr layer induces an aligned crystalline structure in the hard magnetic layer that causes the hard magnetic layer to have a magnetic anisotropy.
    Type: Grant
    Filed: December 22, 2006
    Date of Patent: December 7, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi, Wipul Pemsiri Jayasekara
  • Patent number: 7839607
    Abstract: A method is presented for fabricating a CPP read head having a CPP read head sensor and a hard bias layer which includes forming a strip of sensor material in a sensor material region, and depositing strips of fast-milling dielectric material in first and second fast-milling dielectric material regions adjacent to the sensor material region. A protective layer and a layer of masking material are deposited on the strip of sensor material and the strips of fast-milling dielectric material to provide masked areas and exposed areas. A shaping source, such as an ion milling source, is provided which shapes the exposed areas. Hard bias material is then deposited on the regions of sensor material and fast-milling dielectric material to form caps on each of these regions. The caps of hard bias material and the masking material are then removed from each of these regions.
    Type: Grant
    Filed: August 7, 2007
    Date of Patent: November 23, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Robert E. Fontana, Jr., Ying Hong, Wipul Pemsiri Jayasekara, Howard Gordon Zolla
  • Patent number: 7826182
    Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has a ferromagnetic alloy comprising Co, Fe and Ge in the sensor's free layer and/or pinned layer. The sensor may be a simple pinned structure, in which case the pinned layer may be formed of the CoFeGe ferromagnetic alloy. Alternatively, the sensor may have an AP-pinned layer structure, in which case the AP2 layer may be formed of the CoFeGe ferromagnetic alloy. The Ge-containing alloy comprises Co, Fe and Ge, wherein Ge is present in the alloy in an amount between about 20 and 40 atomic percent, and wherein the ratio of Co to Fe in the alloy is between about 0.8 and 1.2. More particularly, the CoFeGe alloy may consist essentially of only Co, Fe and Ge according to the formula (CoxFe(100-x))(100-y)Gey where the subscripts represent atomic percent, x is between about 45 and 55, and y is between about 23 and 37.
    Type: Grant
    Filed: July 23, 2007
    Date of Patent: November 2, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
  • Patent number: 7810228
    Abstract: An example method for manufacturing a magneto-resistance effect element involves irradiating inert gas ions to enhance an adhesive force between an area around an oxide layer and a metallic layer.
    Type: Grant
    Filed: July 5, 2007
    Date of Patent: October 12, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Yoshihiko Fuji
  • Patent number: 7813088
    Abstract: A magnetoresistance effect device has a fixed ferromagnetism layer, a free ferromagnetism layer, and a barrier layer sandwiched by these ferromagnetic layers. It is constituted so that CoFeB whose amount of addition of boron B (b: atomic %) is 21%?b?23% may be used for the free ferromagnetism layer. In the magnetic resistance effect element, a magnetostrictive constant does not change steeply near the magnetostrictive constant zero. A MR ratio is maintained to be high.
    Type: Grant
    Filed: September 27, 2006
    Date of Patent: October 12, 2010
    Assignee: Canon Anelva Corporation
    Inventors: Koji Tsunekawa, David D. Djayaprawira
  • Patent number: 7813086
    Abstract: Producing a thin film magnetic head includes forming a pair of openings in a predetermined region of a TMR layer formed on a lower magnetic shield layer; forming a pair of bias-applying layers in the pair of openings so that an upper surface thereof is located above an upper surface of the TMR layer; laminating a metal layer that covers the upper surface of a portion located between the pair of bias-applying layers in the TMR layer and the upper surface of the pair of bias-applying layers; forming a resist layer across the upper surface of a portion located above the pair of bias-applying layers in the metal layer and the upper surface of a portion located above the TMR layer in the metal layer; and etching a part of the TMR layer and a part of the pair of bias-applying layers with the resist layer being as a mask.
    Type: Grant
    Filed: May 21, 2007
    Date of Patent: October 12, 2010
    Assignee: TDK Corporation
    Inventors: Kosuke Tanaka, Kazuki Sato, Eiji Komura
  • Patent number: 7813202
    Abstract: A thin-film magnetic device comprises, on a substrate, a composite assembly deposited by cathode sputtering and consists of a first layer made of a ferromagnetic material with a high rate of spin polarization, the magnetization of which is in plane in the absence of any electric or magnetic interaction, a second layer made of a magnetic material with high perpendicular anisotropy, the magnetization of which is outside the plane of said layer in the absence of any electric or magnetic interaction, and coupling of which with said first layer induces a decrease in the effective demagnetizing field of the entire device, a third layer that is in contact with the first layer via its interface opposite to that which is common to the second layer and made of a material that is not magnetic and not polarizing for electrons passing through the device.
    Type: Grant
    Filed: August 3, 2007
    Date of Patent: October 12, 2010
    Assignees: Commissariat a l'Energie Atomique, Centre National de la Recherche Scientifique
    Inventors: Bernard Rodmacq, Bernard Dieny
  • Patent number: 7808750
    Abstract: The thin-film magnetic head of the invention comprises a magneto-resistive effect device including a multilayer film and a bias mechanism portion including a bias magnetic field-applying layer formed on each widthwise end of the multilayer film. When the magneto-resistive effective device including a multilayer film and the bias mechanism portion are viewed in plane on their own, the uppermost extremity of the rear end of the magneto-resistive effect device and the uppermost extremity of the rear end of the bias mechanism portion lie at substantially the same depth-wise position, and the rear slant of the bias mechanism portion is gentler in gradient than the rear slat of the magneto-resistive effect device. It is thus possible just only to facilitate the fabrication of the device but also to achieve several advantages of being a lower rate of occurrence of noise, higher reliability and higher yields.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: October 5, 2010
    Assignee: TDK Corporation
    Inventors: Takumi Yanagisawa, Takayasu Kanaya
  • Patent number: 7804667
    Abstract: An MR element incorporates a nonmagnetic conductive layer, and a pinned layer and a free layer that are disposed to sandwich the nonmagnetic conductive layer. Each of the pinned layer and the free layer includes a Heusler alloy layer. The Heusler alloy layer contains a Heusler alloy in which atoms of a magnetic metallic element are placed at body-centered positions of unit cells, and an additive element that is a nonmagnetic metallic element that does not constitute the Heusler alloy. At least one of the pinned layer and the free layer includes a region in which the concentration of the additive element increases as the distance from the nonmagnetic conductive layer decreases, the region being adjacent to the nonmagnetic conductive layer.
    Type: Grant
    Filed: March 20, 2007
    Date of Patent: September 28, 2010
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Yoshihiro Tsuchiya, Tomohito Mizuno, Koji Shimazawa
  • Patent number: 7804668
    Abstract: A hard bias (HB) structure for longitudinally biasing a free layer in a MR sensor is disclosed that is based on HB easy axis growth perpendicular to an underlying seed layer which is formed above a substrate and along two sidewalls of the sensor. In one embodiment, a conformal soft magnetic layer that may be a top shield contacts the HB layer to provide direct exchange coupling that compensates HB surface charges. Optionally, a thin capping layer on the HB layer enables magneto-static shield-HB coupling. After HB initialization, HB regions along the sensor sidewalls have magnetizations that are perpendicular to the sidewalls as a result of surface charges near the seed layer. Sidewalls may be extended into the substrate (bottom shield) to give enhanced protection against side reading. The top surface of the seed layer may be amorphous or crystalline to promote HB easy axis perpendicular growth.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: September 28, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Yuchen Zhou, Kenichi Takano, Kunliang Zhang
  • Patent number: 7800868
    Abstract: A magnetic sensor includes a sensor stack having a first magnetic portion, a second magnetic portion, and a barrier layer between the first magnetic portion and the second magnetic portion. At least one of the first magnetic portion and the second magnetic portion includes a multilayer structure having a first magnetic layer having a positive magnetostriction adjacent to the barrier layer, a second magnetic layer, and an intermediate layer between the first magnetic layer and the second magnetic layer. The magnetic sensor has an MR ratio of at least about 80% when the magnetic sensor has a resistance-area (RA) product of about 1.0 ?·?m2.
    Type: Grant
    Filed: December 16, 2005
    Date of Patent: September 21, 2010
    Assignee: Seagate Technology LLC
    Inventors: Zheng Gao, Brian W. Karr, Song Xue, Eric L. Granstrom, Khuong T. Tran, Yi X. Li
  • Publication number: 20100232075
    Abstract: A method and apparatus for detecting the presence of magnetic beads is disclosed. By providing both a static magnetic field and a magnetic field that alternates in the MHz range, or beyond, the bead can be excited into FMR (ferromagnetic resonance). The appearance of the latter is then detected by a magneto-resistive type of sensor. This approach offers several advantages over prior art methods in which the magnetic moment of the bead is detected directly.
    Type: Application
    Filed: May 12, 2010
    Publication date: September 16, 2010
    Inventor: Vuchen Zhou
  • Publication number: 20100232066
    Abstract: A magneto-resistive effect (MR) element includes a first magnetic layer and a second magnetic layer in which a relative angle of magnetization directions of the first and second magnetic layers changes according to an external magnetic field; and a spacer layer that is provided between the first magnetic layer and the second magnetic layer. The spacer layer contains gallium nitride (GaN) as a main component.
    Type: Application
    Filed: March 10, 2009
    Publication date: September 16, 2010
    Applicant: TDK CORPORATION
    Inventors: Shinji Hara, Yoshihiro Tsuchiya, Tsutomu Chou, Hironobu Matsuzawa
  • Publication number: 20100226048
    Abstract: A magneto-resistance effect element, a magneto-resistance effect head, a magnetic storage and a magnetic memory, in which noise caused by a spin-transfer torque is reduced, are provided. In a fixed magnetization layer or a free magnetization layer of a magneto-resistance effect element including the fixed magnetization layer, a spacer layer and the free magnetization layer; a layer containing one element selected from the group consisting of Ti, Zr, Nb, Mo, Ru, Rh, Pd, Ag, La, Hf, Ta, W, Re, Os, Ir, Pt and Au is disposed.
    Type: Application
    Filed: September 22, 2006
    Publication date: September 9, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideaki Fukuzawa, Masahiro Takashita, Hiromi Yuasa, Yoshihiko Fuji, Hitoshi Iwasaki
  • Patent number: 7791844
    Abstract: A magnetoresistive sensor having a magnetically stable free layer fabricated from a material having a positive magnetostriction such as a Co—Fe—B alloy. Although the free layer is fabricated from a material that has a positive magnetostriction, which would ordinarily make the free layer unstable, the magnetization of the free layer remains stable because of an induced magnetic anisotropy that has an easy axis of magnetization oriented parallel to the Air-bearing Surface (ABS). This magnetic anisotropy of the free layer is induced by an anisotropic texturing of the surface of the free layer. The resulting anisotropic surface texture is produced by an ion milling process that utilizes an ion beam directed at an acute angle relative to the normal to the surface of the wafer whereon the sensor is fabricated while the wafer is held on a stationary chuck.
    Type: Grant
    Filed: April 19, 2007
    Date of Patent: September 7, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew Joseph Carey, Jeffrey Robinson Childress, Stefan Maat, James L. Nix
  • Patent number: 7784171
    Abstract: A method is provided for manufacturing a magneto-resistive device. The magneto-resistive device is for reducing the deterioration in the characteristics of the device due to annealing. The magneto-resistive device has a magneto-resistive layer formed on one surface side of a base, and an insulating layer formed of two layers and deposited around the magneto-resistive layer. The layer of the insulating layer closest to the base is made of a metal or semiconductor oxide. This layer extends over end faces of a plurality of layers made of different materials from one another, which make up the magneto-resistive device, and is in contact with the end faces of the plurality of layers with the same materials.
    Type: Grant
    Filed: May 4, 2007
    Date of Patent: August 31, 2010
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Tetsuya Kuwashima, Norio Takahashi
  • Patent number: 7787220
    Abstract: A free layer of an MR element incorporates a first layer, a second layer, a third layer, a fourth layer, a fifth layer and a sixth layer that are stacked in this order on a nonmagnetic conductive layer. The absolute value of magnetostriction constant of the free layer is 1×10?6 or smaller. The coercivity of the free layer is 20×79.6 A/m or smaller. The first layer is made of an alloy containing ‘a’ atomic percent cobalt and (100?a) atomic percent iron wherein ‘a’ falls within a range of 20 to 50 inclusive. The second layer is made of an alloy containing ‘b’ atomic percent cobalt and (100?b) atomic percent iron wherein ‘b’ falls within a range of 70 to 90 inclusive. In addition, oxidation treatment is given to a surface of the second layer farther from the first layer.
    Type: Grant
    Filed: March 29, 2006
    Date of Patent: August 31, 2010
    Assignee: TDK Corporation
    Inventors: Tomohito Mizuno, Daisuke Miyauchi
  • Publication number: 20100214701
    Abstract: An MR element according to the present invention has the superior effects that further improve an MR ratio because a structure of a spacer layer 40 is configured of a certain three-layer structure with certain materials, and at least one of a first ferromagnetic layer 30 and a second ferromagnetic layer 50 contains a certain amount of an element selected from the group of nitrogen (N), carbon (C), and oxygen (O).
    Type: Application
    Filed: February 26, 2009
    Publication date: August 26, 2010
    Applicant: TDK CORPORATION
    Inventors: Yoshihiro Tsuchiya, Shinji Hara, Tsutomu Chou, Hironobu Matsuzawa
  • Publication number: 20100214700
    Abstract: A thin film magnetic head includes a first through fourth free layers, a spacer layer, and a bias magnetic field application layer. The first and second free layers are magnetized in opposite directions of each other in the orthogonal direction to the ABS when the bias magnetic field is applied to the first and second free layers, and are exchange-coupled such that an angle between the magnetization direction of the bias magnetic field and the first free layer is acute and such that an angle between the magnetization direction of the bias magnetic field and the second free layer is acute. Similarly, the third and fourth layers have the same configuration.
    Type: Application
    Filed: February 26, 2009
    Publication date: August 26, 2010
    Applicant: TDK CORPORATION
    Inventors: Shinji Hara, Yoshihiro Tsuchiya
  • Patent number: 7779535
    Abstract: An MR effect element that can obtain the sufficient back flux-guide effect under the condition of reducing the capacitance between the upper and lower electrode layers is provided. The element comprises: an MR effect multilayer provided on the lower electrode layer; an insulating layer surrounding a rear side surface and side surfaces opposed to each other in track width direction of the MR effect multilayer; and an upper electrode layer provided on the MR effect multilayer and the insulating layer, the insulating layer having a concave portion filled with a portion of the upper electrode layer, the concave portion positioned near the rear side surface of the MR effect multilayer, and a bottom point of a concave of the concave portion positioned at the same level or a lower level in stacking direction compared to an upper surface of the free layer.
    Type: Grant
    Filed: November 24, 2006
    Date of Patent: August 24, 2010
    Assignee: TDK Corporation
    Inventors: Takayasu Kanaya, Kazuki Sato
  • Patent number: 7782577
    Abstract: A magnetic random access memory structure comprising an anti-ferromagnetic layer structure, a crystalline ferromagnetic structure physically coupled to the anti-ferromagnetic layer structure and a ferromagnetic free layer structure physically coupled to the crystalline ferromagnetic structure.
    Type: Grant
    Filed: June 6, 2006
    Date of Patent: August 24, 2010
    Assignees: Infineon Technologies AG, ALTIS Semiconductor, SNC
    Inventors: Wolfgang Raberg, Ulrich Klostermann
  • Patent number: 7771570
    Abstract: This application discloses a method and apparatus for manufacturing a magnetoresistive multilayer film having a structure where an antiferromagnetic layer, a pinned-magnetization layer, a nonmagnetic spacer layer and a free-magnetization layer are laminated on a substrate in this order. A film for the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. A film for an extra layer interposed between the substrate and the antiferromagnetic layer is deposited by sputtering as oxygen gas is added to a gas for the sputtering. The film for the antiferromagnetic layer is deposited by sputtering as a gas mixture of argon and another gas of larger atomic number than argon is used.
    Type: Grant
    Filed: November 30, 2007
    Date of Patent: August 10, 2010
    Assignee: Canon Anelva Corporation
    Inventors: David Djulianto Djayaprawira, Koji Tsunekawa, Motonobu Nagai
  • Patent number: 7773348
    Abstract: Methods and apparatus provide improved properties of a hard bias layer of a magnetoresistance sensor. The properties of the hard bias layer are improved by using a multilayer seed structure that includes a chromium-containing layer disposed between two tungsten-containing layers.
    Type: Grant
    Filed: March 2, 2006
    Date of Patent: August 10, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7770284
    Abstract: A manufacturing method of an MR element in which current flows in a direction perpendicular to layer planes, includes forming on a lower electrode layer an MR multi-layered film having a cap layer at a top thereof, forming a mask on the cap layer of the MR multi-layered film, patterning the MR multi-layered film by milling through the mask to form an MR multi-layered structure, forming a magnetic domain control bias layer by using a lift off method using the mask, after forming the magnetic domain control bias layer, forming an additional cap layer on the cap layer and a part of the magnetic domain control bias layer, planarizing a top surface of the additional cap layer and the magnetic domain control bias layer, and forming an upper electrode layer on the planarized top surface.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: August 10, 2010
    Assignee: TDK Corporation
    Inventors: Naoki Ohta, Takeo Kagami
  • Publication number: 20100195253
    Abstract: MR devices and associated methods of fabrication are disclosed. An MR device includes an MR element and a bias structure on either side of the MR element for biasing a free layer of the MR element. The bias structure includes an amorphous buffer layer, a first seed layer formed from Cr, a second seed layer formed from a non-magnetic Cr alloy, and a hard bias magnetic layer. The second seed layer formed from the non-magnetic Cr alloy is formed between the Cr seed layer and the hard bias magnetic layer. An example of a non-magnetic Cr alloy is Chromium-Molybdenum (CrMo).
    Type: Application
    Filed: April 8, 2010
    Publication date: August 5, 2010
    Inventors: James M. Freitag, Mustafa M. Pinarbasi
  • Publication number: 20100182723
    Abstract: A magnetic detector includes a magnetoresistive element and an impact sensor. The magnetoresistive element has a plurality of element-constituent layers that are stacked and include a free layer having a magnetization direction that changes in response to a magnetic field to be detected by the magnetic detector. The impact sensor has a plurality of sensor-constituent layers that are made of materials the same as those of the element-constituent layers and stacked in the same order as the element-constituent layers. The plurality of sensor-constituent layers include an impact detecting layer corresponding to the free layer and having a magnetization direction that changes by an inverse magnetostrictive effect in response to distortion created in the impact detecting layer by an impact received by the magnetic detector. The impact detecting layer exhibits a greater amount of change in magnetization direction when the magnetic detector receives an impact, compared with the free layer.
    Type: Application
    Filed: January 21, 2009
    Publication date: July 22, 2010
    Applicant: TDK CORPORATION
    Inventor: Takumi Yanagisawa
  • Patent number: 7760474
    Abstract: A method and system for providing a magnetic element are described. The method and system include providing a pinned layer, a barrier layer, and a free layer. The free layer includes a first ferromagnetic layer, a second ferromagnetic layer, and an intermediate layer between the first ferromagnetic layer and the second ferromagnetic layer. The barrier layer resides between the pinned layer and the free layer and includes MgO. The first ferromagnetic layer resides between the barrier layer and the intermediate layer. The first ferromagnetic layer includes at least one of CoFeX and CoNiFeX, with X being selected from the group of B, P, Si, Nb, Zr, Hf, Ta, Ti, and being greater than zero atomic percent and not more than thirty atomic percent. The first ferromagnetic layer is ferromagnetically coupled with the second ferromagnetic layer.
    Type: Grant
    Filed: July 14, 2006
    Date of Patent: July 20, 2010
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Zhitao Diao, Eugene Youjun Chen
  • Patent number: 7760475
    Abstract: A magnetoresistance effect element includes a pinned layer having a fixed magnetization direction, a free layer having a magnetization direction variable depending on an external magnetic field, and a nonmagnetic spacer layer disposed between the pinned layer and the free layer. The free layer includes a Heusler alloy layer and a magnetostriction reduction layer made of a 4th group element, a 5th group element, or a 6th group element.
    Type: Grant
    Filed: March 12, 2007
    Date of Patent: July 20, 2010
    Assignee: TDK Corporation
    Inventors: Tomohito Mizuno, Yoshihiro Tsuchiya, Kei Hirata
  • Publication number: 20100177440
    Abstract: Foundation layers of a thin film magnetic head are disposed between insulating layers and bias magnetic field application layers, and are configured of Cr or Cr alloy. The insulating layers are configured of a Si oxide such that the Si content of the Si oxide is in the range of 30˜56 at % (atom %) and that the atom ratio of oxygen to Si (O/Si) is in the range of 0.8˜1.3. With the configuration, the occurrence rate of noise is reduced.
    Type: Application
    Filed: January 13, 2009
    Publication date: July 15, 2010
    Applicant: TDK CORPORATION
    Inventors: Takayasu Kanaya, Kei Hirata, Yohei Koyanagi, Seiichi Takayama, Shinji Hara, Toshiyuki Ayukawa
  • Publication number: 20100177441
    Abstract: A thin film magnetic head has a magneto-resistive (MR) effect element including an MR effect film formed by sequentially layering a magnetic pinned layer, a nonmagnetic layer and a free layer, and a pair of bias magnetic field application layers formed at junction tapered parts formed on both end parts of the magneto-resistive effect film in the width direction via insulating layers. Further, magnetic pinned layer oxidized films whose thickness is Hx (unit: nm) are disposed on end parts of the magnetic pinned layer at the junction tapered parts, free layer oxidized films whose thickness is Hf (unit: nm) are disposed on end parts of the free layer at the junction tapered parts, and the oxidized films are configured such that the thickness ratio (Hx/Hf) is not more than 0.5.
    Type: Application
    Filed: January 13, 2009
    Publication date: July 15, 2010
    Applicant: TDK CORPORATION
    Inventor: Takayasu Kanaya
  • Publication number: 20100177449
    Abstract: A composite free layer having a FL1/insertion/FL2 configuration is disclosed for achieving high dR/R, low RA, and low ? in TMR or GMR sensors. Ferromagnetic FL1 and FL2 layers have (+) ? and (?) ? values, respectively. FL1 may be CoFe, CoFeB, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, or Nb. FL2 may be CoFe, NiFe, or alloys thereof with Ni, Ta, Mn, Ti, W, Zr, Hf, Tb, Nb, or B. The thin insertion layer includes at least one magnetic element such as Co, Fe, and Ni, and at least one non-magnetic element selected from Ta, Ti, W, Zr, Hf, Nb, Mo, V, Cr, or B. In a TMR stack with a MgO tunnel barrier, dR/R>60%, ?˜1×10?6, and RA=1.2 ohm-um2 when FL1 is CoFe/CoFeB/CoFe, FL2 is CoFe/NiFe/CoFe, and the insertion layer is CoTa or CoFeBTa.
    Type: Application
    Filed: January 14, 2009
    Publication date: July 15, 2010
    Inventors: Tong Zhao, Hui-Chuan Wang, Min Li, Kunliang Zhang
  • Patent number: 7755929
    Abstract: First and second tunnel junctions having a common electrode composed of a nonmagnetic conductor and each of which has a counterelectrode composed of a ferromagnet are spaced apart from each other by a distance that is shorter than a spin diffusion length of the nonmagnetic conductor. The first tunnel junction injects spin from the ferromagnet into the nonmagnetic conductor and the second tunnel junction detects, between the ferromagnetic metal and the nonmagnetic conductor, a voltage that accompanies spin injection of the first tunnel junction. The nonmagnetic conductor may be a semiconductor or semimetal that is lower in carrier density than a metal. The common electrode alternatively may be composed of a superconductor. A spin injection device thus provided can exhibit a large signal voltage with a low current and under low magnetic field and can be miniaturized in device size.
    Type: Grant
    Filed: November 20, 2003
    Date of Patent: July 13, 2010
    Assignee: Japan Science and Technology Agency
    Inventors: Kouichiro Inomata, Sadamichi Maekawa, Saburo Takahashi
  • Patent number: 7751156
    Abstract: Tunneling magnetoresistive (TMR) elements and associated methods of fabrication are disclosed. In one embodiment, the TMR element includes a ferromagnetic pinned layer structure, a tunnel barrier layer, and a free layer having a dual-layer structure. In one embodiment, the free layer includes a first amorphous free layer and a second amorphous free layer. In another embodiment, the free layer includes a first polycrystalline free layer and a second amorphous free layer. The compositions of the first free layer and the second free layer of the dual layer structure differ to provide improved TMR performance and controlled magnetostriction. In one example, the first free layer may have a composition optimized for TMR while the second free layer may have a composition optimized for magnetostriction.
    Type: Grant
    Filed: September 29, 2006
    Date of Patent: July 6, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Daniele Mauri, Satoshi Shigematsu, Alexander M. Zeltser
  • Patent number: 7746603
    Abstract: A magnetoresistive sensor and method for forming the magnetoresistive sensor. The magnetoresistive sensor includes a first layer and an antiparallel free layer disposed on the first layer. The antiparallel free layer includes a first free layer disposed on the first layer and a first ferromagnetic coupling free layer disposed on the first free layer. The first ferromagnetic coupling layer is configured to provide increased coupling between the first free layer and an antiferromagnetic coupling layer. The antiparallel free layer also includes the antiferromagnetic coupling layer disposed on the first ferromagnetic coupling free layer, a second ferromagnetic coupling free layer disposed on the antiferromagnetic coupling layer, and a second free layer disposed on the second ferromagnetic coupling free layer. The second ferromagnetic coupling layer is configured to provide increased coupling between the second free layer and the antiferromagnetic coupling layer.
    Type: Grant
    Filed: December 19, 2006
    Date of Patent: June 29, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal S. Gill
  • Patent number: 7746602
    Abstract: A magnetic read head and a method for manufacturing a magnetic read head are provided. In one embodiment, the method includes providing the magnetic read head comprising a pinning layer disposed over a substrate of the magnetic read head, a pinned layer, a reference layer, a tunneling barrier layer, and a free layer, wherein the free layer is in contact with the tunneling barrier layer. The method further includes milling partially through the free layer from a back surface, thereby creating an exposed face of the free layer which is parallel to the substrate and oxidizing a portion of the free layer between the exposed face and the tunneling barrier layer. The method further includes milling through the free layer, tunneling barrier layer, reference layer, pinned layer, and pinning layer along lateral sides of the magnetic read head.
    Type: Grant
    Filed: June 21, 2006
    Date of Patent: June 29, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal S. Gill
  • Patent number: 7742262
    Abstract: A magnetoresistive element includes a first magnetic layer a magnetization direction of which is substantially pinned, a second magnetic layer a magnetization direction of which varies depending on an external field, a magnetic spacer layer provided between the first magnetic layer and the second magnetic layer, and electrodes which supply a current perpendicularly to a plane of a stacked film including the first magnetic layer, the magnetic spacer layer and the second magnetic layer. In this element, the magnetization directions of the first and the second magnetic layers are substantially orthogonal at zero external field.
    Type: Grant
    Filed: August 31, 2007
    Date of Patent: June 22, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Hitoshi Iwasaki
  • Patent number: 7739787
    Abstract: In an MR element, each of a pinned layer and a free layer includes a Heusler alloy layer. The Heusler alloy layer has two surfaces that are quadrilateral in shape and face toward opposite directions. The Heusler alloy layer includes one crystal grain that touches four sides of one of the two surfaces. In a method of manufacturing the MR element, a layered film to be the MR element is formed and patterned, and then heat treatment is performed on the layered film patterned, so that crystal grains included in a film to be the Heusler alloy layer in the layered film grow and one crystal grain that touches four sides of one of the surfaces of the film to be the Heusler alloy layer is thereby formed.
    Type: Grant
    Filed: March 8, 2007
    Date of Patent: June 22, 2010
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Yoshihiro Tsuchiya, Tomohito Mizuno, Daisuke Miyauchi, Shinji Hara, Takahiko Machita
  • Patent number: 7742261
    Abstract: The conventional free layer in a TMR read head has been replaced by a composite of two or more magnetic layers, one of which is iron rich The result is an improved device that has a higher MR ratio than prior art devices, while still maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is also described.
    Type: Grant
    Filed: January 12, 2005
    Date of Patent: June 22, 2010
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Hui-Chuan Wang, Chyu-Jiuh Torng
  • Patent number: 7738218
    Abstract: A magnetic detection element capable of maintaining the ?RA at a high level and reducing the magnetostriction by improving a material for a free magnetic layer, as well as a method for manufacturing the same, is provided. The free magnetic layer includes a laminate composed of a CoMnX alloy layer formed from a metal compound represented by a compositional formula CoaMnbXc (where X represents at least one of Ge, Ga, In, Si, Pb, Zn, and Sb and a+b+c=100 atomic percent) and a CoMnZ alloy layer formed from a metal compound represented by a compositional formula CodMneZf (where Z represents at least one of Sn and Al and d+e+f=100 atomic percent). In this manner, the magnetostriction of the free magnetic layer can be reduced.
    Type: Grant
    Filed: May 17, 2006
    Date of Patent: June 15, 2010
    Assignee: TDK Corporation
    Inventors: Yosuke Ide, Masamichi Saito, Masahiko Ishizone, Naoya Hasegawa
  • Patent number: 7738220
    Abstract: A magnetoresistance effect element, comprising a nonmagnetic spacer layer, first and second ferromagnetic layers separated by the nonmagnetic spacer layer, the first ferromagnetic layer having a magnetization direction at an angle relative to a magnetization direction of the second ferromagnetic layer at zero applied magnetic field, the magnetization of the first ferromagnetic layer freely rotating in a magnetic field signal, a magnetoresistance effect-improving layer comprising a plurality of metal films and disposed in contact with the first ferromagnetic layer so that the first ferromagnetic layer is disposed between the nonmagnetic spacer layer and the magnetoresistance effect-improving layer, one of the plurality of metal films disposed in contact with the first ferromagnetic layer contains metal element of not solid solution with metal element of the first ferromagnetic layer and a nonmagnetic underlayer or a nonmagnetic protecting layer disposed in contact with the magnetoresistance effect-improving la
    Type: Grant
    Filed: July 17, 2007
    Date of Patent: June 15, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Yuzo Kamiguchi, Katsuhiko Koui, Shin-ichi Nakamura, Hitoshi Iwasaki, Kazuhiro Saito, Hiromi Fuke, Masatoshi Yoshikawa, Susumu Hashimoto, Masashi Sahashi
  • Patent number: 7733614
    Abstract: Embodiments in accordance with the present invention provide a method of manufacturing a magneto-resistive head which can realize high sensitivity and good linear response characteristics with low noise even if a track width becomes narrower. A uniaxial anisotropy unaffected by annealing which is due to the orientation of the crystal grain growth direction, is induced in a magnetic layer. The free magnetic layer has the synthetic antiferromagnetic construction: first magnetic layer/interlayer antiferromagnetic coupling layer/second magnetic layer, the magnitude of the antiferromagnetic coupling is adjusted, and linear response characteristics are obtained even if a longitudinal biasing field applying mechanism is not provided.
    Type: Grant
    Filed: January 24, 2007
    Date of Patent: June 8, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kenichi Meguro, Hiroyuki Katada, Katsumi Hoshino, Hiroyuki Hoshiya
  • Patent number: 7724481
    Abstract: A magnetic sensing element is provided. A free magnetic layer has a three-layer structure including CoMn? sublayers each composed of a metal compound represented by the formula: Co2xMnx?y. The ? contains an element ? and Sb, the element ? being at least one element selected from Ge, Ga, In, Si, Pb, Zn, Sn, and Al. The concentration x and the concentration y are each represented in terms of atomic percent and satisfy the equation: 3x+y=100 atomic percent. One of the CoMn? sublayers is in contact with a lower nonmagnetic material layer. The other CoMn? sublayer is in contact with upper nonmagnetic material layer. As a result, it is possible to achieve a high ?RA and a lower interlayer coupling magnetic field Hin compared with the known art.
    Type: Grant
    Filed: August 15, 2006
    Date of Patent: May 25, 2010
    Assignee: TDK Corporation
    Inventors: Yosuke Ide, Masamichi Saito, Masahiko Ishizone, Kazumasa Nishimura, Naoya Hasegawa
  • Patent number: 7719801
    Abstract: Magnetoresistive (MR) elements having flux guides defined by the free layer are disclosed. The MR element includes a free layer, a spacer/barrier layer, a pinned layer, and a pinning layer. A back edge of the free layer (opposite the sensing surface of the MR element) extends past a back edge of the spacer/barrier layer. The portion of the free layer extending past the back edge of the spacer/barrier layer defines a continuous flux guide. The flux guide is processed to reduce the conductive characteristics of the flux guide, thereby reducing current shunt loss in the flux guide.
    Type: Grant
    Filed: April 18, 2006
    Date of Patent: May 18, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventor: Hardayal S. Gill
  • Patent number: 7715154
    Abstract: An apparatus comprises a ferromagnetic free layer having a first magnetic moment and having a magnetization that rotates in response to an external magnetic field, a first ferromagnetic reference layer positioned adjacent to a first side of the ferromagnetic free layer and having a second magnetic moment that is greater than the first magnetic moment of the ferromagnetic free layer, a second ferromagnetic reference layer positioned adjacent to a second side of the ferromagnetic free layer and having a third magnetic moment that is greater than the first magnetic moment of the ferromagnetic free layer, a first non-magnetic spacer layer positioned between the ferromagnetic free layer and the first ferromagnetic reference layer, a second non-magnetic spacer layer positioned between the ferromagnetic free layer and the second ferromagnetic reference layer, and a source of magnetic field for biasing the first and second ferromagnetic reference layers.
    Type: Grant
    Filed: April 13, 2005
    Date of Patent: May 11, 2010
    Assignee: Seagate Technology LLC
    Inventors: Mark William Covington, Nils Jan Gokemeijer
  • Patent number: 7715155
    Abstract: A thin-film magnetic head includes a lower magnetic shield layer, an MR multi-layered structure formed on the lower magnetic shield layer so that current flows in a direction perpendicular to surfaces of laminated layers, an insulation layer formed to surround the MR multi-layered structure, an additional metal layer laminated on at least the MR multi-layered structure, an upper electrode layer made of a soft magnetic material laminated on the additional metal layer and the insulation layer, and an upper magnetic shield layer laminated on the upper electrode layer. The additional metal layer has a multi-layered structure including a nonmagnetic metal layer and a soft magnetic layer laminated on the nonmagnetic metal layer, and has a length along a track-width direction of the MR multi-layered structure larger than a width of a magnetization-free layer in the MR effect multi-layered structure.
    Type: Grant
    Filed: April 11, 2007
    Date of Patent: May 11, 2010
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Kazuki Sato, Kosuke Tanaka, Takayasu Kanaya, Naoki Ohta
  • Patent number: 7697246
    Abstract: A current perpendicular to plane (CPP) magnetoresistive sensor having a current path defined by first and second overlying insulation layers between which an electrically conductive lead makes content with a surface of the sensor stack. The current path being narrower than the width of the sensor stack allows the outer edges of the sensor stack to be moved outside of the active area of the sensor. This results in a sensor that is unaffected by damage at outer edges of the sensor layers. The sensor stack includes a free layer that is biased by direct exchange coupling with a layer of antiferromagnetic material (AFM layer). The strength of the exchange field can be controlled by adding Cr to the AFM material to ensure that the exchange field is sufficiently weak to avoid pinning the free layer.
    Type: Grant
    Filed: August 10, 2006
    Date of Patent: April 13, 2010
    Assignee: Hitachi Global Storage Technologies Netherlands B. V.
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Patent number: 7695761
    Abstract: The method and system for providing a spin tunneling element are disclosed. The method and system include depositing a pinned layer, a barrier layer, and a free layer. The barrier layer has a first crystal structure and a texture. The free layer includes a first ferromagnetic layer and a second ferromagnetic layer. The first ferromagnetic is adjacent to the second ferromagnetic layer and between the second ferromagnetic layer and the barrier layer. The first ferromagnetic layer has the first crystal structure and the texture, while the second ferromagnetic layer has a second crystal structure different from the first crystal structure.
    Type: Grant
    Filed: December 21, 2006
    Date of Patent: April 13, 2010
    Assignee: Western Digital (Fremont), LLC
    Inventors: Yong Shen, Qunwen Leng