Detail Of Free Layer Or Additional Film For Affecting Or Biasing The Free Layer Patents (Class 360/324.12)
  • Patent number: 7495869
    Abstract: A magnetoresistive effect sensor includes a pinned layer, a nonmagnetic spacer layer, and a free layer having a total thickness of at least 10 nm. The sensor has insulating films disposed on both side surfaces of the spin valve film. The sensor has hard magnetic films disposed on the insulating films for applying a biasing magnetic field to the free layer. Each hard magnetic film extends toward the free layer in a vicinity of the spin valve film, such that as each hard magnetic film extends toward the spin valve film, a cross-sectional area thereof in a plane perpendicular to the layer width direction becomes progressively smaller. Each hard magnetic film has, in a plane parallel to the air bearing surface, a first boundary line which at least partially faces the free layer and substantially defines an end point of the hard magnetic film in the layer width direction.
    Type: Grant
    Filed: September 14, 2005
    Date of Patent: February 24, 2009
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Kazuki Sato, Takayasu Kanaya
  • Publication number: 20090046398
    Abstract: A method of biasing a magneto resistive sensor element includes providing at least one magneto resistive sensor element having a magnetic sensitivity along a first axis that is parallel to a plane of the at least one sensor element. A magnet is positioned adjacent to the at least one sensor element for biasing the at least one sensor element, wherein the magnet has a magnetization that is non-perpendicular to the plane of the at least one sensor element, and wherein the magnetization includes a component parallel to the plane of the at least one sensor element that increases a sensitive range of the at least one sensor element along the first axis.
    Type: Application
    Filed: August 14, 2007
    Publication date: February 19, 2009
    Inventors: Tobias Werth, Jurgen Zimmer
  • Publication number: 20090040662
    Abstract: An MR element includes a free layer having a direction of magnetization that changes in response to an external magnetic field, a pinned layer having a fixed direction of magnetization, and a spacer layer disposed between these layers. The spacer layer includes a first region, a second region and a third region that are each in the form of a layer and that are arranged in a direction intersecting the plane of each of the foregoing layers. The second region is sandwiched between the first region and the third region. The first region and the third region are each composed of an oxide semiconductor, and the second region includes at least a nonmagnetic conductor phase out of the nonmagnetic conductor phase and an oxide semiconductor phase.
    Type: Application
    Filed: August 8, 2007
    Publication date: February 12, 2009
    Applicant: TDK CORPORATION
    Inventors: Tsutomu Chou, Tomohito Mizuno
  • Publication number: 20090040663
    Abstract: A magnetic memory includes a stack, a first writing wire, and a second writing wire. The stack includes a magnetic pinned layer, a tunnel barrier insulating layer, and a magnetic free layer, so as to form a magnetic tunnel junction (MTJ). The MTJ has an easy axis. The first writing wire is disposed under the stack. The included angle between the first writing wire and the easy axis of the MTJ is smaller than 45 degrees and greater than 0 degrees on a projected plane. The second writing wire is disposed above the stack. The included angle between the second writing wire and the easy axis of the MTJ is smaller than 45 degrees and greater than 0 degrees on the projected plane.
    Type: Application
    Filed: October 9, 2008
    Publication date: February 12, 2009
    Applicant: Industrial Technology Research Institute
    Inventors: Yuan-Jen Lee, Ding-Yeong Wang, Chien-Chung Hung
  • Publication number: 20090034135
    Abstract: Embodiments of the present invention help to provide a single element type differential magnetoresistive magnetic head capable of achieving high resolution and high manufacturing stability. According to one embodiment, a magnetoresistive layered film is formed by stacking an underlayer film, an antiferromagnetic film, a ferromagnetic pinned layer, a non-magnetic intermediate layer, a soft magnetic free layer, a long distance antiparallel coupling layered film, and a differential soft magnetic free layer. The long distance antiparallel coupling layered film exchange-couples the soft magnetic free layer and the differential soft magnetic free layer in an antiparallel state with a distance of about 3 nanometers through 20 nanometers. By manufacturing the single element type differential magnetoresistive magnetic head using the magnetoresistive layered film, it becomes possible to achieve the high resolution and the high manufacturing stability without spoiling the GMR effect.
    Type: Application
    Filed: July 17, 2008
    Publication date: February 5, 2009
    Applicant: Hitachi Global Storage Technologies
    Inventors: Hiroyuki Hoshiya, Kenichi Meguro, Katsumi Hoshino, Yo Sato, Hiroyuki Katada, Kazuhiro Nakamoto
  • Publication number: 20090027813
    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: Application
    Filed: July 23, 2007
    Publication date: January 29, 2009
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
  • Patent number: 7483245
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, if a pinned layer and a free layer have a stacked construction of a magnetic layer and a non-magnetic layer or a stacked construction of a magnetic layer and a magnetic layer, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Grant
    Filed: March 4, 2008
    Date of Patent: January 27, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuzo Kamiguchi, Hiromi Yuasa, Tomohiko Nagata, Hiroaki Yoda
  • Patent number: 7483246
    Abstract: A magnetoresistive sensor having a novel seed layer that allows a bias layer formed there over to have exceptional hard magnetic properties when deposited over a crystalline structure such as an AFM layer of in a partial mill sensor design. The seed layer structure may be a CrMo/Si/CrMo sandwich or may also be a CrMo/Si/Cr sandwich and interrupts the epitaxial growth of an underlying crystalline structure, allowing a hard magnetic material formed over the seed layer to have a desired grain structure that is different from that of the underlying crystalline layer.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: January 27, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 7480122
    Abstract: A magnetic detecting device and a method of manufacturing the magnetic detecting device are provided. Non-magnetic material layer-side magnetic layers of second fixed magnetic layers form a fixed magnetic layer. Each of the non-magnetic material layer-side magnetic layers and a free magnetic layer is formed of a layer, for example, a CoMnGeCu layer. In the CoMnGeCu layer, a bulk scattering coefficient may become larger, as compared with a CoMnGe layer. As a result, it is possible to increase the product between a magnetoresistance variation and a device area. Further, the ferromagnetic coupling magnetic field can be decreased. The Cu is added by a range which is larger than 0 at. % and not more than 17.5 at. % (average composition ratio).
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: January 20, 2009
    Assignee: TDK Corporation
    Inventors: Yosuke Ide, Masamichi Saito, Masahiko Ishizone, Naoya Hasegawa, Kazumasa Nishimura
  • Patent number: 7475471
    Abstract: A GMR read head for a magnetic head, in which the hard bias layers are fabricated immediately next to the side edges of the free magnetic layer, and such that the midplane of the hard bias layer and the midplane of the free magnetic layer are approximately coplanar. The positioning of the hard bias layer is achieved by depositing a thick hard bias seedlayer, followed by an ion milling step is to remove seed layer sidewall deposits. Thereafter, the hard bias layer is deposited on top of the thick seed layer. Alternatively, a first portion of the hard bias seed layer is deposited, followed by an ion milling step to remove sidewall deposits. A thin second portion of the seed layer is next deposited, and the hard bias layer is then deposited.
    Type: Grant
    Filed: November 13, 2006
    Date of Patent: January 13, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 7477491
    Abstract: It has been found that the insertion of a copper laminate within CoFe, or a CoFe/NiFe composite, leads to higher values of CPP GMR and DRA. However, this type of structure exhibits very negative magnetostriction, in the range of high ?10?6 to ?10?5. This problem has been overcome by giving the copper laminates an oxygen exposure treatment When this is done, the free layer is found to have a very low positive magnetostriction constant. Additionally, the value of the magnetostriction constant can be adjusted by varying the thickness of the free layer and/or the position and number of the oxygen treated copper laminates.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: January 13, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Kunliang Zhang, Masashi Sano, Koichi Terunuma, Simon Liao, Kochan Ju
  • Patent number: 7472469
    Abstract: A method is disclosed for fabricating a read sensor for a magnetic head for a hard disk drive having a read sensor stack and two lateral stacks. The method of fabrication includes forming lateral stacks on a gap layer, surrounding a groove to form a template. The read sensor stack is then formed in the groove, which defines the lateral dimensions of the read sensor stack, and lead layers are then formed on the lateral stacks. Also disclosed is a read head for a disk drive having a sensor stack defined by pre-established lateral stacks, and a disk drive having the read head.
    Type: Grant
    Filed: September 20, 2005
    Date of Patent: January 6, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: David Eugene Heim, Kim Y. Lee, Tsann Lin, Jih-Shiuan Luo, Chun-Ming Wang
  • Patent number: 7474514
    Abstract: Exchange coupling energy between an anti-ferromagnetic layer and a first ferromagnetic layer, and an anti-ferromagnetic coupling energy between the first ferromagnetic layer and a second ferromagnetic layer by way of an Ru anti-ferromagnetic coupling layer of a spin valve device are increased thereby increasing the magnetoresistance ratio and decreasing the coercivity of the free layer of the spin valve film. In an MnPt anti-ferromagnetic bottom type synthetic ferri-type spin valve film in which an underlayer, an anti-ferromagnetic layer comprising MnPt, a first ferromagnetic layer comprising CoFe, an anti-ferromagnetic coupling layer comprising Ru, a second ferromagnetic layer comprising CoFe, an intermediate non-magnetic layer comprising Cu, a free layer comprising synthetic films of CoFe and NiFe and a protective layer are stacked over a substrate, the Fe composition X in CoFeX of the first ferromagnetic layer is set as about: 20<x?50 at %.
    Type: Grant
    Filed: June 29, 2005
    Date of Patent: January 6, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kouichi Nishioka, Satoshi Shigematsu, Yasunari Tajima
  • Publication number: 20090002893
    Abstract: The invention provides a giant magneto-resistive effect device (CPP-GMR device) having a CPP (current perpendicular to plane) structure comprising a spacer layer, and a fixed magnetized layer and a free layer stacked one upon another with said spacer layer interposed between them, with a sense current applied in a stacking direction, wherein the free layer functions such that the direction of magnetization changes depending on an external magnetic field, and the spacer layer comprises a first and a second nonmagnetic metal layer, each formed of a nonmagnetic metal material, and a semiconductor oxide layer interposed between the first and the second nonmagnetic metal layer, wherein the semiconductor oxide layer that forms a part of the spacer layer is made of zinc oxide, tin oxide, indium oxide, and indium tin oxide (ITO), the first nonmagnetic metal layer is made of Cu, and the second nonmagnetic metal layer is substantially made of Zn.
    Type: Application
    Filed: June 26, 2007
    Publication date: January 1, 2009
    Applicant: TDK CORPORATION
    Inventors: Yoshihiro Tsuchiya, Tomohito Mizuno, Shinji Hara
  • Publication number: 20090002899
    Abstract: According to one embodiment, a magnetoresistive element includes a magnetization fixed layer, an intermediate layer provided on the magnetization fixed layer, a free layer provided on the intermediate layer, a separating layer composed of nonmagnetic metal and provided on the free layer, and a fluctuation compensated layer whose static magnetic coupling with the free layer is disconnected by the separating layer, whose magnetization direction is fixed so as to be antiparallel to the magnetization direction of the magnetization fixed layer, and provided on the separating layer.
    Type: Application
    Filed: June 27, 2008
    Publication date: January 1, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Katsuhiko Koui
  • Patent number: 7471492
    Abstract: A magnetoresistive element has a first magnetic layer and a second magnetic layer separate from each other, the first magnetic layer and the second magnetic layer each having a magnetization whose direction is substantially pinned, and a non-magnetic conductive layer formed in contact with the first magnetic layer and the second magnetic layer and electrically connecting the first and second magnetic layers, the non-magnetic conductive layer forming a path of spin-polarized electrons from one of the magnetic layer to the other magnetic layer, the non-magnetic conductive layer comprising a portion located between the first magnetic layer and the second magnetic layer, the portion being a sensing area.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: December 30, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Susumu Hashimoto, Hitoshi Iwasaki
  • Patent number: 7467459
    Abstract: A current in plane giant magnetoresistive (GMR) sensor having a hard bias layer that extends along the back edge (strip height) of the sensor rather than from the sides of the sensor. The hard bias layer preferably extends beyond the track width of the sensor. Electrically conductive leads, which may be a highly conductive material such as Cu, Rh or Au, or may be an electrically conductive magnetic material extend from the sides of the sensor stack. The bias layer is separated from the sensor stack and from the leads by thin layer of electrically conductive material, thereby preventing current shunting through the hard bias layer.
    Type: Grant
    Filed: April 18, 2005
    Date of Patent: December 23, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hardayal Singh Gill, Kuok San Ho
  • Patent number: 7468870
    Abstract: Making thinner the magnetic domain control layer deteriorates the magnetic properties. Also, disturbances tend to increase the magnetization dispersion of the magnetic domain control layer, thereby lowering the magnetic domain control bias magnetic field. In one embodiment of the invention, a first magnetic domain control layer is provided in the proximity of the free layer of the GMR sensor in such a way that the track width is Twr1. Outside the first magnetic domain control layer is provided a second magnetic domain control layer. The second magnetic domain control layer placed outside the first magnetic domain control layer gives the first magnetic domain control layer an external bias field. The amount of magnetization of the tip of the first magnetic domain control layer is polarized and increased by the bias magnetic field from the second magnetic domain control layer.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: December 23, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masatoshi Arasawa, Wataru Kimura, Shuichi Kojima, Koji Okazaki, Norihiro Ookawa
  • Patent number: 7466522
    Abstract: A magnetic head including an electrical lead layer that is comprised of a material having an ordered-phase crystalline structure. In a preferred embodiment, the ordered-phase crystalline structure of the electrical lead is epitaxially matched to the crystalline structure of the hard bias layer upon which it is formed, and there is no need for a seed layer for the electrical leads. Electrical leads comprised of the materials used in the invention having an ordered-phase crystalline structure, particularly a B2, L10, L11, and L12 structure, will have significantly reduced resistivity over the prior art electrical leads that are typically composed of rhodium or tantalum. As a result, thinner electrical leads can be fabricated which carry the same, or even greater, current than the prior art rhodium or tantalum leads. The preferred leads are comprised of NiAl, FeCo, or CuZn having a B2 crystalline structure, and alternative embodiments are comprised of CuAu, Cu3Au, CuPt, and Cu3Pt.
    Type: Grant
    Filed: February 27, 2006
    Date of Patent: December 16, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Michael Andrew Parker, Mustafa Michael Pinarbasi
  • Patent number: 7466525
    Abstract: A magnetic sensing element exhibiting a large ?RA is provided, in which a free magnetic layer has a small coercive force Hc and a small magnetostriction constant ?s. The free magnetic layer includes a Co2MnZ alloy layer (where Z may represent at least one element selected from the group consisting of Al, Sn, In, Sb, Ga, Si, Ge, Pb, and Zn) and a (NiaFe100-a)bX100-b alloy layer (where X may represent at least one element selected from the group consisting of Cu, Au, Ag, Zn, Mn, Al, Cd, Zr, and Hf, a may represent a composition ratio satisfying 80<a?100, and b may represent a composition ratio satisfying 60<b?100). Consequently, the magnetostriction constant ?s and the coercive force Hc of the free magnetic layer may be decreased and the soft magnetic properties of the free magnetic layer may be improved.
    Type: Grant
    Filed: May 1, 2006
    Date of Patent: December 16, 2008
    Assignee: TDK Corporation
    Inventors: Naoya Hasegawa, Masamichi Saito, Yosuke Ide, Masahiko Ishizone
  • Patent number: 7463459
    Abstract: A self pinned magnetoresistive sensor that has a relatively thick compressive material at either side to assist with self pinning. A shield having recessed portions at either side of the sensor area allows room for a thicker compressive layer than would otherwise be possible.
    Type: Grant
    Filed: February 18, 2004
    Date of Patent: December 9, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Meng Ding, Robert E. Fontana, Jr., Kuok San Ho, Neil Leslie Robertson, Ching Hwa Tsang
  • Patent number: 7460343
    Abstract: A magnetoresistive sensor having an in stack bias layer with an engineered magnetic anisotropy in a direction parallel with the medium facing surface. The in-stack bias layer may be constructed of CoPt, CoPtCr or some other magnetic material and is deposited over an underlayer that has been ion beam etched. The ion beam etch has been performed at an angle with respect to normal in order to form anisotropic roughness in form of oriented ripples or facets. The anisotropic roughness induces a uniaxial magnetic anisotropy substantially parallel to the medium facing surface in the hard magnetic in-stack bias layer deposited thereover.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: December 2, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew Joseph Carey, Jeffrey Robinson Childress, Eric Edward Fullerton, Stefan Maat
  • Patent number: 7457085
    Abstract: A magnetoresistive sensor having a hard bias layer with an engineered magnetic anisotropy in a direction substantially parallel with the medium facing surface. The hard bias layer may be constructed of CoPt, CoPtCr or some other magnetic material and is deposited over an underlayer that has been ion beam etched. The ion beam etch has been performed at an angle with respect to normal in order to induce anisotropic roughness on its surface for example in form of oriented ripples or facets. The anisotropic roughness induces a uniaxial magnetic anisotropy substantially parallel to the medium facing surface in the hard magnetic bias layers deposited there over.
    Type: Grant
    Filed: March 31, 2005
    Date of Patent: November 25, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew Joseph Carey, Jeffrey Robinson Childress, Eric Edward Fullerton, Stefan Maat
  • Publication number: 20080278865
    Abstract: A magnetoresistive element includes an antiferromagnetic layer formed from a layer containing manganese, a layered magnetization fixed layer which includes a first magnetization fixed layer located over a side of the antiferromagnetic layer and formed from a layer containing a ferromagnetic material and a platinum group metal, a second magnetization fixed layer formed from a layer containing a ferromagnetic material, and a first nonmagnetic intermediate layer located between the first magnetization fixed layer and the second magnetization fixed layer, a magnetic free layer formed from a layer containing a ferromagnetic material, and a second nonmagnetic intermediate layer located between the layered magnetization fixed layer and the magnetic free layer.
    Type: Application
    Filed: May 2, 2008
    Publication date: November 13, 2008
    Applicant: CANON ANELVA CORPORATION
    Inventors: Koji Tsunekawa, David D. Djayaprawira
  • Publication number: 20080278867
    Abstract: A magnetoresistance device is provided for improving thermal stability of a magnetoresistance element by preventing inter-diffusion between a conductor (such as a via and an interconnection) for connecting the magnetoresistance element to another element and layers constituting the magnetoresistance element. A magnetoresistance device is composed of a magnetoresistance element, a non-magnetic conductor providing electrical connection between said magnetoresistance element to another element, and a diffusion barrier structure disposed between said conductor and said magnetoresistance element, the magnetoresistance element including a free ferromagnetic layer having reversible spontaneous magnetization, a fixed ferromagnetic layer having fixed spontaneous magnetization, and a tunnel dielectric layer disposed between said free and fixed ferroelectric layer.
    Type: Application
    Filed: June 12, 2008
    Publication date: November 13, 2008
    Applicant: NEC CORPORATION
    Inventors: Yoshiyuki FUKUMOTO, Ken-ichi SHIMURA, Atsushi KAMIJO
  • Publication number: 20080278866
    Abstract: At both sides of an element portion, a first hard bias layer having a higher residual magnetization Mr and a second hard bias layer having a higher coercive force Hc are deposited in that order from the bottom with one end of the first hard bias layer being closed close to a free magnetic layer. A film thickness ratio of the first hard bias layer in a whole hard bias layer is from 35% to 75%. This stabilizes magnetization in the free magnetic layer to reduce asymmetry, thus enabling improvement in stability of reproducing characteristics including noise suppression.
    Type: Application
    Filed: May 7, 2008
    Publication date: November 13, 2008
    Inventors: Masahiko Ishizone, Yasuo Hayakawa
  • Publication number: 20080278864
    Abstract: A CPP-GMR spin valve having a composite spacer layer comprised of at least one metal (M) layer and at least one semiconductor or semi-metal (S) layer is disclosed. The composite spacer may have a M/S, S/M, M/S/M, S/M/S, M/S/M/S/M, or a multilayer (M/S/M)n configuration where n is an integer ?1. The pinned layer preferably has an AP2/coupling/AP1 configuration wherein the AP2 portion is a FCC trilayer represented by CoZFe(100-Z)/FeYCo(100-Y)/CoZFe(100-Z) where y is 0 to 60 atomic %, and z is 75 to 100 atomic %. In one embodiment, M is Cu with a thickness from 0.5 to 50 Angstroms and S is ZnO with a thickness of 1 to 50 Angstroms. The S layer may be doped with one or more elements. The dR/R ratio of the spin valve is increased to 10% or greater while maintaining acceptable EM and RA performance.
    Type: Application
    Filed: May 11, 2007
    Publication date: November 13, 2008
    Inventors: Kunliang Zhang, Min Li, Moris Dovek, Yue Liu
  • Patent number: 7450351
    Abstract: A magnetoresistive element of a CPP type configuration including a fixed magnetic layer, a first non-magnetic layer, a free magnetic layer, and a second non-magnetic layer is disclosed. The magnetoresistive element includes a first interface layer situated between the free magnetic layer and the first non-magnetic layer, and a second interface layer situated between the free magnetic layer and the second non-magnetic layer. The first interface layer and the second interface layer include a material mainly having CoNiFe.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: November 11, 2008
    Assignee: Fujitsu Limited
    Inventors: Hirotaka Oshima, Keiichi Nagasaka, Arata Jogo, Yutaka Shimizu, Atsushi Tanaka
  • Patent number: 7446985
    Abstract: A magnetic head and magnetic storage system containing such a head, the head including a free layer and a layer of metal oxide substantially epitaxially formed relative to the free layer. Preferably, the layer of metal oxide is a crystalline structure, and is of ZnO.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: November 4, 2008
    Assignees: Agency for Science Technology and Research, Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Wen-yaung Lee, Jinshan Li, Kebin Li, Yihong Wu
  • Patent number: 7446987
    Abstract: A hard bias structure for biasing a free layer in a MR element within a magnetic read head is comprised of a soft magnetic underlayer such as NiFe and a hard bias layer comprised of Co78.6Cr5.2Pt16.2 or Co65Cr15Pt20 that are rigidly exchange coupled to ensure a well aligned longitudinal biasing direction with minimal dispersions. The hard bias structure is formed on a BCC seed layer such as CrTi to improve lattice matching. The hard bias structure may be laminated in which each of the underlayers and hard bias layers has a thickness that is adjusted to optimize the total Hc, Mrt, and S values. The present invention encompasses CIP and CPP spin values, MTJ devices, and multi-layer sensors. A larger process window for fabricating the hard bias structure is realized and lower asymmetry output and NBLW (normalized base line wandering) reject rates during a read operation are achieved.
    Type: Grant
    Filed: December 17, 2004
    Date of Patent: November 4, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Mao-Min Chen, Chyu-Jiuh Torng, Min Li, Chen-Jung Chien
  • Patent number: 7446986
    Abstract: A magnetoresistive sensor having an in stack bias structure. The sensor includes a bias spacer that allows biasing of free layer magnetic moment in a direction orthogonal to the magnetic moment of the biasing layer.
    Type: Grant
    Filed: August 31, 2004
    Date of Patent: November 4, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Satoru Araki, Jeffrey Robinson Childress, Stefan Maat, Daniele Mauri, Matthew Joseph Carey
  • Patent number: 7441326
    Abstract: In a magnetic sensor, a lower terminal layer, a magnetosensitive layer, and a cover film are simultaneously patterned into substantially the same size. The opposing surface of the lower terminal layer, which opposes the magnetosensitive film is substantially superposed on one opposing surface of the magnetosensitive film. The opposing surface of the upper terminal layer, which opposes the magnetosensitive film is formed into a shape smaller than and included in the other opposing surface of the magnetosensitive film. This implements a magnetic sensor which uses a CPP structure and is yet readily processible and which includes a substantially accurate fine CPP structure in accordance with a desired output.
    Type: Grant
    Filed: August 17, 2006
    Date of Patent: October 28, 2008
    Assignee: Fujitsu Limited
    Inventors: Yoshihiko Seyama, Atsushi Tanaka
  • Patent number: 7443638
    Abstract: Disclosed herein is a magnetoresistive structure, for example useful as a spin-valve or GMR stack in a magnetic sensor, and a fabrication method thereof. The magnetoresistive structure uses twisted coupling to induce a perpendicular magnetization alignment between the free layer and the pinned layer. Ferromagnetic layers of the free and pinned layers are exchange-coupled using antiferromagnetic layers having substantially parallel exchange-biasing directions. Thus, embodiments can be realized that have antiferromagnetic layers formed of a same material and/or having a same blocking temperature. At least one of the free and pinned layers further includes a second ferromagnetic layer and an insulating layer, such as a NOL, between the two ferromagnetic layers. The insulating layer causes twisted coupling between the two ferromagnetic layers, rotating the magnetization direction of one 90 degrees relative to the magnetization direction of the other.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: October 28, 2008
    Assignee: Taiwan Semiconductor Manufacturing Company Ltd.
    Inventors: Yu-Jen Wang, Chih-Huang Lai, Wen-Chin Lin, Denny Tang, Chao-Hsiung Wang
  • Patent number: 7440241
    Abstract: A magnetoresistive head and a fabricating method thereof accomplishing high read sensitivity and excellent linear response with low noise even if track width narrowing makes progress are provided. In one embodiment, using a magnetoresistive film having a laminated body of a pinned layer/an intermediate layer/a free layer/a separate layer/a first ferromagnetic layer/a 90-degree magnetic interlayer coupling layer/a second ferromagnetic layer, and the magnetizations of both the pinned layer and the second ferromagnetic layer are fixed nearly in the direction along the sensor height. On the other hand, the magnetizations of the first ferromagnetic layer and the second ferromagnetic layer have an interlayer interaction being directed in nearly orthogonal directions to each other through the 90-degree magnetic interlayer coupling layer, and the first ferromagnetic layer has a magnetization directed nearly in the direction along the track width in zero external magnetic field.
    Type: Grant
    Filed: October 3, 2005
    Date of Patent: October 21, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Katsumi Hoshino, Hiroyuki Hoshiya, Hiroyuki Katada, Kenichi Meguro
  • Patent number: 7440243
    Abstract: A read sensor of the current-perpendicular-to-the-planes (CPP) type includes a sensor stack structure formed in a central region between first and second shield layers which serve as leads for the read sensor; insulator layers formed in side regions adjacent the central region; seed layer structures formed over the insulator layers in the side regions; and hard bias layers formed over the seed layer structures in the side regions. The hard bias layers are made of a nitrogenated cobalt-based alloy, such as nitrogenated cobalt-platinum (CoPt). Suitable if not exemplary coercivity and squareness properties are exhibited using the nitrogenated cobalt-based alloy. The hard bias layers may be formed by performing an ion beam deposition of cobalt-based materials using a sputtering gas (e.g. xenon) and nitrogen as a reactive gas.
    Type: Grant
    Filed: April 9, 2007
    Date of Patent: October 21, 2008
    Assignee: Hitachi Global Storage Technologies
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7440240
    Abstract: Embodiments of the invention provide a spin-valve type magnetic head that satisfies the requirements of both high read output and stability with narrow tracks. In one embodiment, a domain control film is formed on a magnetoresistive layered film in the same track width. A double closed flux path structure that uses three magnetic layers is employed with magnetic coupled structure in both ends of the track. The three magnetic layers are a soft magnetic free layer, a domain-stabilization ferromagnetic layer, and a soft magnetic anti-parallel layer.
    Type: Grant
    Filed: April 8, 2005
    Date of Patent: October 21, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hiroyuki Hoshiya, Katsumi Hoshino, Masahiko Hatatani, Kenichi Meguro
  • Patent number: 7440242
    Abstract: A magnetic head with improved hard magnet properties includes a sensor stack structure of current-perpendicular-to-the-planes (CPP) type formed in a central region between first and second shield layers, and a multi-layered seed layer structure formed in side regions adjacent the central region. The multi-layered structure has a first layer including nitrogenated nickel-tantalum (NiTa+N) and a second layer including chromium-molybdenum (CrMo), which are formed over an insulator in the side regions. A hard bias layer formed over the multi-layered structure is preferably a cobalt-based alloy. Methods of making the magnetic head are also described.
    Type: Grant
    Filed: April 5, 2007
    Date of Patent: October 21, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 7440239
    Abstract: It is possible to obtain sensitivity which can achieve an excellent error rate with a high recording density. There are provided a magnetization free layer which has two opposed main surfaces, one of which is set to be generally parallel to an air bearing surface; an intermediate layer which is formed on an opposite side face of the magnetization free layer from a medium to come in contact with the magnetization free layer; and a pair of magnetization pinned layers which are formed on an opposite side face of the intermediate layer from the magnetization free layer to come in contact with the intermediate layer and extend outwardly. A sense current flows from one magnetization pinned layer to the other magnetization pinned layer through the magnetization free layer.
    Type: Grant
    Filed: September 29, 2003
    Date of Patent: October 21, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuzo Kamiguchi, Masayuki Takagishi, Yuichi Ohsawa
  • Patent number: 7436638
    Abstract: A CPP magnetic sensor is disclosed with a ferromagnetic layer that extends in a first direction a first distance; a nonferromagnetic spacer layer that adjoins the ferromagnetic layer and extends in the first direction a second distance that is substantially equal to the first distance; and a ferromagnetic structure that is separated from the ferromagnetic layer by the spacer layer, the ferromagnetic structure having a first section that extends in the first direction a third distance that is substantially equal to the second distance, the ferromagnetic structure having a second section that is disposed further than the first section from the spacer layer, the second section extending at least twice as far as the first section in the first direction. The ferromagnetic structure can be used for in-stack bias or pinning of free or pinned layers, respectively, and side shields can be provided for high areal density.
    Type: Grant
    Filed: September 18, 2007
    Date of Patent: October 14, 2008
    Assignee: Western Digital (Fremont), LLC
    Inventor: Tao Pan
  • Patent number: 7433163
    Abstract: A seedlayer structure for a high coercivity hard bias layer is disclosed, having at least one bi-layer seedlayer, including a CrMo layer, and a W layer fabricated on the CrMo layer. A hard bias layer is fabricated on the bi-layer seedlayer. Preferably, the seedlayer structure includes two bi-layer seedlayers, which including a first CrMo layer, a first W layer fabricated on the first CrMo layer, a second CrMo layer fabricated on the first W layer, and a second W layer fabricated on the second CrMo layer. Also disclosed is a high coercivity hard bias stack structure, a magnetic read head for a disk drive having a high coercivity hard bias stack structure and a method for fabricating a coercivity hard bias layer for a magnetic read head.
    Type: Grant
    Filed: February 13, 2006
    Date of Patent: October 7, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mohamad Towfik Krounbi, Mustafa Michael Pinarbasi
  • Publication number: 20080239590
    Abstract: A magneto-resistance effect element, including: a first magnetization layer of which a magnetization is substantially fixed in one direction; a second magnetization layer of which a magnetization is rotated in accordance with an external magnetic field; an intermediate layer which contains insulating portions and magnetic metallic portions and which is provided between the first magnetic layer and the second magnetic layer; and a pair of electrodes to flow current in a direction perpendicular to a film surface of a multilayered film made of the first magnetic layer, the intermediate layer and the second magnetic layer; wherein the magnetic metallic portions of the intermediate layer contain non-ferromagnetic metal.
    Type: Application
    Filed: February 22, 2008
    Publication date: October 2, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TDK CORPORATION
    Inventors: Hiromi Fuke, Susumu Hashimoto, Masayuki Takagishi, Hitoshi Iwasaki
  • Publication number: 20080239586
    Abstract: A current perpendicular to plane magneto-resistance effect element includes: a magneto-resistance effect film comprised of a fixed magnetization layer, a free magnetization layer, and a complex spacer layer including an insulating layer and current paths formed through the insulating layer; a biasing mechanism for stabilizing the free magnetization layer; a shielding mechanism for ensuring a reproducing resolution of the magneto-resistance effect element; and a pair of electrodes for flowing a current perpendicular to a film surface of the magneto-resistance effect element; wherein a resistance area product (RA:?×?m2) is set to 0.00062×?{square root over ((GAP))}×TW+0.06 when a track width of the magneto-resistance effect element is defined as TW (nm) and a gap length of the magneto-resistance effect element is defined as GAP (nm).
    Type: Application
    Filed: March 18, 2008
    Publication date: October 2, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TDK CORPORATION
    Inventors: Masayuki Takagishi, Hitoshi Iwasaki, Masahiro Takashita, Michiko Hara, Dan Abels, Xin Li
  • Publication number: 20080239591
    Abstract: A magneto-resistance effect element, including: a fixed magnetization layer of which a magnetization is substantially fixed in one direction; a free magnetization layer of which a magnetization is rotated in accordance with an external magnetic field and which is formed opposite to the fixed magnetization layer; a spacer layer including a current confining layer with an insulating layer and a conductor to pass a current through the insulating layer in a thickness direction thereof and which is located between the fixed magnetization layer and the free magnetization layer; a thin film layer which is located in a side opposite to the spacer layer relative to the free magnetization layer; and a functional layer containing at least one element selected from the group consisting of Si, Mg, B, Al which is formed in or on at least one of the fixed magnetization layer, the free magnetization layer and the thin film layer.
    Type: Application
    Filed: March 11, 2008
    Publication date: October 2, 2008
    Applicants: KABUSHIKI KAISHA TOSHIBA, TDK CORPORATION
    Inventors: Yoshihiko Fuji, Hideaki Fukuzama, Hiromi Yuasa, Kunliang Zhang, Min Li, Michiko Hara, Yoshinari Kurosaki
  • Publication number: 20080239589
    Abstract: We describe a CPP MTJ MRAM element that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes a tunneling barrier layer of MgO and a non-magnetic CPP layer of Cu or Cr and utilizes a novel synthetic free layer having three ferromagnetic layers mutually exchange coupled in pairwise configurations. The free layer comprises an inner ferromagnetic and two outer ferromagnetic layers, with the inner layer being ferromagnetically exchange coupled to one outer layer and anti-ferromagnetically exchange coupled to the other outer layer. The ferromagnetic coupling is very strong across an ultra-thin layer of Ta, Hf or Zr of thickness preferably less than 0.4 nm.
    Type: Application
    Filed: March 26, 2007
    Publication date: October 2, 2008
    Inventors: Yimin Guo, Cheng T. Horng, Ru-Ying Tong
  • Patent number: 7428129
    Abstract: A magnetic head with improved hard magnet properties includes a read sensor; a multi-layered seed layer structure in end regions adjacent the read sensor; and a multi-layered seed layer structure formed upon crystalline materials of the read sensor in the end regions. The multi-layered seed layer structure includes a first seed layer made of chromium-molybdenum (Cr—Mo); a second seed layer made of nickel-tantalum (Ni—Ta); and a third seed layer made of chromium-molybdenum (Cr—Mo). The hard bias layer is preferably cobalt-platinum-chromium (Co—Pt—Cr).
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: September 23, 2008
    Assignee: Hitachi Global Storage Technologies Amsterdam
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 7428127
    Abstract: A CPP magnetoresistive effect element includes a free magnetization layer, a fixed magnetization layer, and a plurality of conductive non-magnetic intermediate layers formed between the free magnetization layer and the fixed magnetization layer. An insulating layer and a magnetic layer including magnetic atoms are provided between any two of the non-magnetic intermediate layers.
    Type: Grant
    Filed: January 25, 2005
    Date of Patent: September 23, 2008
    Assignee: Fujitsu Limited
    Inventors: Keiichi Nagasaka, Yoshihiko Seyama, Hirotaka Oshima, Yutaka Shimizu, Atsushi Tanaka
  • Patent number: 7428130
    Abstract: A CPP-type magnetoresistive element including a fixed magnetization layer, a non-magnetic metal layer, and a free magnetization layer that are stacked, and a diffusion prevention layer is disclosed. The free magnetization layer includes CoMnAl. The diffusion prevention layer is provided between the non-magnetic metal layer and the free magnetization layer so as to prevent Mn included in the free magnetization layer from diffusing into the non-magnetic metal layer. CoMnAl has a composition within the area formed by connecting Point A (44, 23, 33), Point B (48, 25, 27), Point C (60, 20, 20), Point D (65, 15, 20), Point E (65, 10, 25), Point F (60, 10, 30), and Point A with straight lines in this order in a ternary composition diagram where coordinates of the composition are expressed as (Co content, Mn content, Al content) with each of the Co, Mn, and Al contents being expressed in atomic percentage.
    Type: Grant
    Filed: April 25, 2006
    Date of Patent: September 23, 2008
    Assignee: Fujitsu Limited
    Inventors: Arata Jogo, Hirotaka Oshima, Takahiro Ibusuki, Yutaka Shimizu, Takuya Uzumaki
  • Patent number: 7426096
    Abstract: A first shielding layer and a second shielding layer are disposed by a given distance. An MR film is disposed in between the first shielding layer and the second shielding layer. The first gap film is formed on the MR film with commensurate to the surface configuration thereof. Magnetic domain controlling films are disposed at both sides of the MR film, respectively. Electrode layers are formed on the magnetic domain controlling layers, respectively. One of the second gap layers is located between the MR film; the magnetic domain controlling layers and the first shielding layer, and the other is located between the first gap layer; the electrode layer and the second shielding layer.
    Type: Grant
    Filed: April 21, 2004
    Date of Patent: September 16, 2008
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Kosuke Tanaka
  • Patent number: 7426097
    Abstract: An enhanced giant magnetoresistive device, and a method of manufacturing the same. The enhanced giant magnetoresistive (GMR) device includes a substrate over which is formed a seed layer. A buffer-oxide layer is formed over the seed layer. Formed over the buffer-oxide layer is a GMR stack. The GMR stack is formed as a three layer sandwich in which the two outside layers are fabricated from ferromagnetic materials, and the inner layer or spacer layer is formed from non-magnetic, conducting materials. The GMR stack may also take the form of spin valves, and/or other GMR stacks. The buffer-oxide layer may be various thicknesses and provide desirable texturing or non-waviness, both of which may allow for a thin spacer layer. Further, the buffer-oxide layer may be configured to prevent Néel-type-orange-peel coupling from dominating RKKY coupling in the GMR device, which may allow for a thin spacer layer.
    Type: Grant
    Filed: July 19, 2002
    Date of Patent: September 16, 2008
    Assignee: Honeywell International, Inc.
    Inventors: Joel Drewes, William Witcraft
  • Patent number: 7426098
    Abstract: A magnetoresistive element includes a magnetoresistive film having a magnetization pinned layer whose magnetization is substantially pinned to one direction, a nonmagnetic intermediate layer, and a magnetization free layer whose magnetization is changed in direction depending on an external magnetic field, in which the magnetization pinned layer or nonmagnetic intermediate layer includes an insulator, and a pair of electrodes electrically connected to the magnetoresistive film so as to supply a sense current in a direction substantially perpendicular to a plane of the magnetoresistive film. The magnetization free layer includes a body-centered cubic layer with a body-centered cubic structure, and the thickness of the body-centered cubic layer is 2 nm or more.
    Type: Grant
    Filed: December 22, 2004
    Date of Patent: September 16, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Susumu Hashimoto, Hitoshi Iwasaki