Detail Of Pinned Film Or Additional Film For Affecting Or Biasing The Pinned Film Patents (Class 360/324.11)
  • Publication number: 20080043380
    Abstract: Intensity of the longitudinal bias field applied to a free soft magnetic layer in a magnetoresistive element can be adjusted after formation, by providing of a composite ferromagnetic layer for longitudinally biasing the free soft magnetic layer. The composite ferromagnetic layer has sub-ferromagnetic layers 15a, 15b, and 15c having different coercive forces. The intensity of the longitudinal bias field is adjusted by inversely rotating the fields of one or more sub-ferromagnetic layers by 180° or 90°, by applying external magnetic fields of appropriate intensity.
    Type: Application
    Filed: March 1, 2007
    Publication date: February 21, 2008
    Inventor: Masanori Akie
  • Patent number: 7333306
    Abstract: A TMR sensor, a CPP GMR sensor and a CCP CPP GMR sensor all include a tri-layered free layer that is of the form CoFe/CoFeB/NiFe, where the atom percentage of Fe can vary between 5% and 90% and the atom percentage of B can vary between 5% and 30%. The sensors also include SyAP pinned layers which, in the case of the GMR sensors include at least one layer of CoFe laminated onto a thin layer of Cu. In the CCP CPP sensor, a layer of oxidized aluminum containing segregated particles of copper is formed between the spacer layer and the free layer. All three configurations exhibit extremely good values of coercivity, areal resistance, GMR ratio and magnetostriction.
    Type: Grant
    Filed: August 23, 2005
    Date of Patent: February 19, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Kunliang Zhang, Hui-Chuan Wang, Yu-Hsia Chen, Min Li
  • Patent number: 7333303
    Abstract: Provided is a magnetoresistive device capable of stably maintaining sufficient output characteristics even under a higher temperature environment while responding to a demand for a higher recording density. The magnetoresistive device comprises an MR film including a fixing layer made of IrMn, an outer pinned layer of which the magnetization direction is fixed in a +Y direction by the fixing layer, and an inner pinned layer of which the magnetization direction is fixed in a ?Y direction by the fixing layer, a pair of conductive lead layers and a constant current circuit which flows a sense current in a +X direction so as to generate a current magnetic field toward a ?Y direction in the inner pinned layer, and in the magnetoresistive device, a conditional expression (1) is satisfied.
    Type: Grant
    Filed: December 29, 2004
    Date of Patent: February 19, 2008
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Yoshihiro Tsuchiya, Kenji Inage
  • Publication number: 20080037184
    Abstract: An exchange-coupling film incorporates an antiferromagnetic layer and a pinned layer. The pinned layer includes a first ferromagnetic layer, a second ferromagnetic layer, a third ferromagnetic layer, a nonmagnetic middle layer, and a fourth ferromagnetic layer that are disposed in this order, the first ferromagnetic layer being closest to the antiferromagnetic layer. The first ferromagnetic layer is made of a ferromagnetic material and has a face-centered cubic structure. The second ferromagnetic layer is made of only iron or an alloy containing x atomic % cobalt and (100?x) atomic % iron, wherein x is greater than zero and smaller than or equal to 60. The third ferromagnetic layer is made of an alloy containing y atomic % cobalt and (100?y) atomic % iron, wherein y is within a range of 65 to 80 inclusive. The antiferromagnetic layer and the first ferromagnetic layer are exchange-coupled to each other. The third and fourth ferromagnetic layers are antiferromagnetically coupled to each other.
    Type: Application
    Filed: June 4, 2007
    Publication date: February 14, 2008
    Applicant: TDK CORPORATION
    Inventors: Takumi Uesugi, Satoshi Miura
  • Publication number: 20080037183
    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: Application
    Filed: August 10, 2006
    Publication date: February 14, 2008
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Patent number: 7330339
    Abstract: A magnetic head having improved self-pinning. The head includes a sensor having an antiparallel (AP) pinned layer structure, where the AP pinned layer structure includes at least two pinned layers having magnetic moments that are self-pinned antiparallel to each other, the pinned layers being separated by an AP coupling layer. A pair of compression layers are positioned towards opposite track edges of the sensor. The compression layers provide compressive stress to the sensor.
    Type: Grant
    Filed: July 25, 2003
    Date of Patent: February 12, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7327539
    Abstract: A CPP giant magnetoresistive (GMR) head includes lower and upper shield layers; and a GMR element disposed between the upper and lower shield layers and comprising a pinned magnetic layer, a free magnetic layer, and a nonmagnetic layer disposed between the pinned magnetic layer and the free magnetic layer. Nonmagnetic metal films are provided directly above the lower shield layer and below the upper shield layer making direct contact with and having larger areas than the pinned magnetic layer and the free magnetic layer, respectively. An antiferromagnetic layer is provided in the rear of the GMR element in the height direction, for pinning the magnetization direction of the pinned magnetic layer. Alternatively, the dimension of the pinned magnetic layer in the height direction is larger than the dimension in the track width direction so that the magnetization direction of the pinned magnetic layer is stabilized without using an antiferromagnetic layer.
    Type: Grant
    Filed: April 13, 2004
    Date of Patent: February 5, 2008
    Assignee: Alps Electric Co., Ltd.
    Inventor: Masamichi Saito
  • Patent number: 7324310
    Abstract: A current perpendicular to plane (CPP) giant magnetoresistive (GMR) sensor having a pinning structure recessed disposed behind the sensor in the stripe height direction.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: January 29, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Publication number: 20080019059
    Abstract: A method for manufacturing a magnetic read sensor and a magnetic read sensor are provided. In one embodiment of the invention, the method includes providing a seed layer disposed over a substrate of the magnetic read sensor, providing a free layer disposed over a seed layer and providing a spacer layer disposed over the free layer. The method further includes providing a pinned layer disposed over the spacer layer. In one embodiment, the pinned layer includes cobalt and iron, wherein the concentration of iron in the pinned layer is between 33 and 37 atomic percent (at. %). The method further includes providing a pinning layer disposed over the pinned layer, wherein the pinning layer is in contact with the pinned layer.
    Type: Application
    Filed: July 20, 2006
    Publication date: January 24, 2008
    Inventors: Jinshan Li, Kouichi Nishioka, Satoshi Shigematsu, Alexander M. Zeltser
  • Patent number: 7320170
    Abstract: Using a beam of xenon ions together with a suitable mask, a GMR stack is ion milled until a part of it, no more than about 0.1 microns thick, has been removed so that a pedestal, having sidewalls comprising a vertical section that includes all of the free layer, has been formed. This is followed by formation of the longitudinal bias and conductive lead layers in the usual way. Using xenon as the sputtering gas enables the point at which milling is terminated to be more precisely controlled.
    Type: Grant
    Filed: April 20, 2004
    Date of Patent: January 22, 2008
    Assignees: Headway Technologies, Inc., TDK Corporation
    Inventors: Stuart Kao, Chunping Luo, Chaopeng Chen, Takahiko Machita, Daisuke Miyauchi, Jei-Wei Chang
  • Publication number: 20080013223
    Abstract: In the GMR device of the CPP structure using the synthetic pinned layer as the fixed magnetization layer (pinned layer), the width W1 of the inner pin layer is set at 50 nm or less; the fixed magnetization layer is configured in such a way as to have a given angle range of tapers at both its ends as viewed from the medium opposite plane; the magnetic volume ratio between the inner and the outer pin layer is allowed to lie in the range of 0.9 to 1.1; and the magnetic thickness ratio between the inner and the outer pin layer is set at 0.8 or less. It is thus possible to make the outer pin layer thin at no cost of the thickness of the inner pin layer forming a part of the synthetic pinned layer yet without doing damage to the function of the synthetic pinned layer itself, viz., resistance to an external magnetic field.
    Type: Application
    Filed: July 5, 2007
    Publication date: January 17, 2008
    Applicant: TDK CORPORATION
    Inventors: Daisuke Miyauchi, Takahiko Machita
  • Publication number: 20070297100
    Abstract: An alignment control film is formed on an alumina film by sputtering. A Ti film, a Ta film, a Ru film, a MgO film or the like is formed as the alignment control film. A lower shield layer is formed on the alignment control film. Crystal grains composing the lower shield layer will be of a columnar crystal grains. The lower shield layer will have the (111) surface exposed to the surface thereof when a Ti film, a Ta film or a Ru film is formed as the alignment control film, whereas the lower shield layer will have the (100) surface exposed to the surface thereof when a MgO film is formed as the alignment control film. A GMR film is then formed on the lower shield layer. The GMR film is formed by first allowing an anti-ferromagnetic film to epitaxially grow on the lower shield layer. The anti-ferromagnetic film will have also the (111) surface or the (100) surface reflecting the crystal structure of the lower shield layer.
    Type: Application
    Filed: October 30, 2006
    Publication date: December 27, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Toyoo Miyajima, Mineharu Tsukada
  • Patent number: 7312958
    Abstract: A method for manufacturing a magnetic disk apparatus having a highly sensitive reproducing head. A spin-valve-type multilayer film composed of an antiferromagnetic layer, a ferromagnetic layer, a nonmagnetic layer and a free magnetic layer is used as a magnetoresistive-effect device for the reproducing head. An antiferromagnetic reaction layer is formed between the antiferromagnetic reaction layer and the ferromagnetic layer. The antiferromagnetic reaction layer is formed of a metallic compound containing oxygen.
    Type: Grant
    Filed: November 28, 2003
    Date of Patent: December 25, 2007
    Assignee: Matsushita Electric Industrial Co., Ltd
    Inventor: Akifumi Aono
  • Patent number: 7312959
    Abstract: At two sides of a multilayer film including a free magnetic layer, a first non-magnetic material layer, and a fixed magnetic layer, extension portions extending from the fixed magnetic layer are formed. At lower sides of the extension portions, a pair of first antiferromagnetic layers is formed with a space therebetween in a track width direction, and in addition, at upper sides of the extension portions, a pair of second antiferromagnetic layers is formed with a space therebetween in the track width direction.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: December 25, 2007
    Assignee: Alps Electric Co., Ltd.
    Inventors: Ryou Nakabayashi, Eiji Umetsu, Naoya Hasegawa
  • Patent number: 7312961
    Abstract: A magnetic head has less variations in the resistance of a magneto-resistive device before and after the magnetic head is left in a high temperature environment so as to have higher stability of the characteristics of the magnetic head against a high temperature environment. A TMR device includes a tunnel barrier layer made of an oxide layer. A DLC film serving as a protection film and an underlying layer therefor are formed on an end face of the TMR device on an air bearing surface side. A layer made of an oxide of a metal or an oxide of a semiconductor is formed between the underlying layer and the end face of the tunnel barrier layer on the air bearing surface side to be in contact with the end face of the tunnel barrier layer.
    Type: Grant
    Filed: September 21, 2004
    Date of Patent: December 25, 2007
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Tetsuya Kuwashima, Kentaro Nagai
  • Patent number: 7312960
    Abstract: A magnetic sensing element is provided in which the magnetization of a pinned magnetic layer is pinned by a uniaxial anisotropy of the pinned magnetic layer itself. A nonmagnetic layer for increasing the coercive force of the pinned magnetic layer is disposed adjacent to the pinned magnetic layer at the opposite side of a nonmagnetic conductive layer. Specifically, the nonmagnetic layer is composed of, for example, Cu. In addition, the thickness of the nonmagnetic layer is adequately controlled.
    Type: Grant
    Filed: March 3, 2005
    Date of Patent: December 25, 2007
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kazumi Matsuzaka, Eiji Umetsu, Naoya Hasegawa
  • Publication number: 20070291422
    Abstract: A method for manufacturing a magnetic field detecting element has the steps of: forming stacked layers by sequentially depositing a pinned layer, a spacer layer, a spacer adjoining layer which is adjacent to the spacer layer, a metal layer, and a Heusler alloy layer in this order, such that the layers adjoin each other; and heat treating the stacked layers in order to form the free layer out of the spacer adjoining layer, the metal layer, and the Heusler alloy layer. The spacer adjoining layer is mainly formed of cobalt and iron, and has a body centered cubic structure, and the metal layer is formed of an element selected from the group consisting of silver, gold, copper, palladium, or platinum, or is formed of an alloy thereof.
    Type: Application
    Filed: February 21, 2007
    Publication date: December 20, 2007
    Applicant: TDK Corporation
    Inventors: Yoshihiro Tsuchiya, Tomohito Mizuno, Kei Hirata, Keita Kawamori, Koji Shimazawa
  • Patent number: 7310209
    Abstract: A magnetoresistive sensor having hard bias layers constructed of CoPtCrB, which high coercivity when deposited over crystalline materials such as an AFM layer or other sensor material. The bias layer material exhibits high coercivity and high moment even when deposited over a crystalline structure such as that of an underlying sensor material by not assuming the crystalline structure of the underlying crystalline layer. The bias layer material is especially beneficial for use in a partial mill sensor design wherein a portion of the sensor layers extends beyond the active area of the sensor and the bias layer must be deposited on the extended portion of sensor material.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: December 18, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7310207
    Abstract: A magnetic sensing element using a Heusler alloy is provided. In the magnetic sensing element, a free magnetic layer composed of a Heusler alloy layer is disposed on a nonmagnetic layer that corresponds to an fcc layer having the face-centered cubic (fcc) structure. Equivalent crystal planes represented as [111] planes in the fcc structure, which are the closest packed planes, are exposed on the surface of the nonmagnetic layer.
    Type: Grant
    Filed: September 29, 2004
    Date of Patent: December 18, 2007
    Assignee: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Masamichi Saito, Yosuke Ide
  • Patent number: 7308751
    Abstract: A magnetic head has less variations in the resistance of a magneto-resistive device before and after the magnetic head is left in a high temperature environment so as to have higher stability of the characteristics of the magnetic head against a high temperature environment. A TMR device includes a tunnel barrier layer made of an oxide layer. A DLC film serving as a protection film and an underlying layer therefor are formed on an end face of the TMR device on an air bearing surface side. A layer made of an oxide of a metal or an oxide of a semiconductor is formed between the underlying layer and the end face of the tunnel barrier layer on the air bearing surface side to be in contact with the end face of the tunnel barrier layer.
    Type: Grant
    Filed: February 27, 2007
    Date of Patent: December 18, 2007
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Tetsuya Kuwashima, Kentaro Nagai
  • Patent number: 7310208
    Abstract: A first magnetic sublayer constituting a pinned magnetic layer is provided in contact with a first magnetostriction-enhancing layer to increase the magnetostriction constant of the first magnetic sublayer. In addition, a nonmagnetic intermediate sublayer constituting the pinned magnetic layer is made of a material having a lattice constant larger than that of Ru, such as a Ru—X alloy, to distort the crystal structures of the first magnetic sublayer and a second magnetic sublayer each in contact with the nonmagnetic intermediate sublayer, increasing the magnetostriction constants of the first magnetic sublayer and the second magnetic sublayer.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: December 18, 2007
    Assignee: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Masamichi Saito, Eiji Umetsu
  • Publication number: 20070274010
    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: Application
    Filed: March 20, 2007
    Publication date: November 29, 2007
    Applicant: TDK CORPORATION
    Inventors: Kei Hirata, Yoshihiro Tsuchiya, Tomohito Mizuno, Koji Shimazawa
  • Patent number: 7301733
    Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film and a pair of electrode. The magnetoresistance effect film having a first magnetic layer whose direction of magnetization is substantially pinned in one direction; a second magnetic layer whose direction of magnetization changes in response to an external magnetic field; a nonmagnetic intermediate layer located between the first and second magnetic layers; and a film provided in the first magnetic layer, in the second magnetic layer, at a interface between the first magnetic layer and the nonmagnetic intermediate layer, and/or at a interface between the second magnetic layer and the nonmagnetic intermediate layer, the film having a thickness not larger than 3 nanometers, and the film has as least one selected from the group consisting of oxide, nitride, oxinitride, phosphide, and fluoride.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: November 27, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Hiromi Fuke, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 7301734
    Abstract: A GMR sensor having improved longitudinal biasing is provided as is a method of forming it. The improved biasing is provided by longitudinal biasing structures in which a soft magnetic layer is interposed between a hard magnetic biasing layer and the lateral edge of the GMR sensor element. The soft magnetic layer eliminates the need for a seed layer directly between the hard magnetic layer and the GMR element and provides improved coupling to the free layer of the GMR element and a substantial reduction in random domain variations.
    Type: Grant
    Filed: August 24, 2005
    Date of Patent: November 27, 2007
    Assignee: Headway Technologies, Inc.
    Inventors: Yimin Guo, Li-Yan Zhu
  • Publication number: 20070253121
    Abstract: A spin accumulation device with high output, high resolution, and low noise. A spin current confined layer is located between a voltage-detection magnetic conductive material and a nonmagnetic conductive material. A spin current alone flows through the spin current confined layer. Due to the confinement of the spin current, since it is possible to prevent the spin current from flowing through excess portions other than the scatterer that exhibits resistance change, the detection efficiency of the spin accumulation device is dramatically increased.
    Type: Application
    Filed: April 25, 2007
    Publication date: November 1, 2007
    Inventors: MASAKI YAMADA, Hiromasa Takahashi
  • Publication number: 20070253122
    Abstract: A magneto-resistive element includes: a first magnetic layer having a substantially fixed magnetization direction; a thin film layer disposed on the first magnetic layer and having at least one of oxide, nitride, oxynitride, and metal; and a second magnetic layer disposed on the thin film layer and having a substantially fixed magnetization direction.
    Type: Application
    Filed: April 5, 2007
    Publication date: November 1, 2007
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Yoshihiko Fuji, Hiromi Yuasa, Hitoshi Iwasaki
  • Publication number: 20070253120
    Abstract: It is possible to provide a magnetoresistive effect element which has thermal stability even if it is made fine and in which the magnetization in the magnetic recording layer can be inverted at a low current density. A magnetoresistive effect element includes: a magnetization pinned layer having a magnetization pinned in a direction; a magnetization free layer of which magnetization direction is changeable by injecting spin-polarized electrons into the magnetization free layer; a tunnel barrier layer provided between the magnetization pinned layer and the magnetization free layer; a first antiferromagnetic layer provided on the opposite side of the magnetization pinned layer from the tunnel barrier layer; and a second antiferromagnetic layer which is provided on the opposite side of the magnetization free layer from the tunnel barrier layer and which is thinner in thickness than the first antiferromagnetic layer.
    Type: Application
    Filed: April 19, 2007
    Publication date: November 1, 2007
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshiaki Saito, Hideyuki Sugiyama, Tomoaki Inokuchi
  • Patent number: 7289303
    Abstract: Magnetoresistive (MR) sensors are disclosed having mechanisms for reducing edge effects such as Barkhausen noise. The sensors include a pinned layer and a free layer with an exchange coupling layer adjoining the free layer, and a ferromagnetic layer having a fixed magnetic moment adjoining the exchange coupling layer. The exchange coupling layer and ferromagnetic layer form a synthetic antiferromagnetic structure with part of the free layer, providing bias that reduces magnetic instabilities at edges of the free layer. Such synthetic antiferromagnetic structures can provide a stronger bias than conventional antiferromagnetic layers, as well as a more exactly defined track width than conventional hard magnetic bias layers. The synthetic antiferromagnetic structures can also provide protection for the free layer during processing, in contrast with the trimming of conventional antiferromagnetic layers that exposes if not removes part of the free layer.
    Type: Grant
    Filed: April 5, 2001
    Date of Patent: October 30, 2007
    Assignee: Western Digital (Fremont), LLC
    Inventors: Kyusik Sin, Ningjia Zhu, Yingjian Chen
  • Patent number: 7287313
    Abstract: A method is provided for preserving the transverse biasing of a GMR (or MR) read head during back-end processing. In a first preferred embodiment, the method comprises magnetizing the longitudinal biasing layers of the read head in a transverse direction, so that the resulting field at the position of the transverse biasing layer places it in a minimum of potential energy which stabilizes its direction. The field of the longitudinal biasing layer is then reset to the longitudinal direction in a manner which maintains the transverse biasing direction. In a second embodiment, a novel fixture for mounting the read head during processing includes a magnetic portion which stabilizes the transverse bias of the read head. The two methods may be used singly or in combination.
    Type: Grant
    Filed: June 30, 2005
    Date of Patent: October 30, 2007
    Assignee: Headway Technologies, Inc.
    Inventors: Yimin Guo, Li-Yan Zhu
  • Patent number: 7289304
    Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has an improved antiparallel (AP) pinned structure. The AP-pinned structure has two ferromagnetic layers separated by a nonmagnetic antiparallel coupling (APC) layer and with their magnetization directions oriented antiparallel. One of the ferromagnetic layers in the AP-pinned structure is the reference layer in contact with the CPP-SV sensor's nonmagnetic electrically conducting spacer layer. In the improved AP-pinned structure each of the ferromagnetic layers has a thickness greater than 30 ?, preferably greater than approximately 50 ?, and the APC layer is either Ru or Ir with a thickness less than 7 ?, preferably about 5 ? or less. The ultrathin APC layer, especially if formed of iridium (Ir), provides significant coupling strength to allow the thick ferromagnetic layers to retain their magnetization directions in a stable antiparallel orientation.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: October 30, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
  • Patent number: 7284316
    Abstract: A method for forming a hard bias structure in a magnetoresistive sensor is disclosed. A magnetoresistive sensor having a soft magnetic bias layer, spacer layer, and a magnetoresistive layer, is formed over a substrate having a gap layer. A mask is formed over a portion of the magnetoresistive sensor structure to define a central region. The masked structure is ion milled to remove portions not shielded by the mask, to form the central region with sloped sides, and to expose a region of the gap layer laterally adjacent the sloped sides. A first underlayer is deposited onto at least the sloped sides at a high deposition angle. A second underlayer is deposited to at least partially overlap the first underlayer, and at a first lower deposition angle. A hard bias layer is deposited over at least a portion of the second underlayer, and at a second lower deposition angle.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: October 23, 2007
    Assignee: Western Digital (Fremont), LLC
    Inventors: Yiming Huai, Jinqiu Zhang, Jing Zhang
  • Patent number: 7283335
    Abstract: In a magnetic detecting element, ferromagnetic layers are formed on both side portions of a free magnetic layer through nonmagnetic intermediate layers, and second antiferromagnetic layers are formed on the ferromagnetic layers with a spacing greater than the spacing between the ferromagnetic layers in the track width direction. Also, in both side portions of the element, the ferromagnetic layers have portions extending from the inner end surfaces of the respective second antiferromagnetic layers toward the center in the track width direction. Furthermore, electrode layers are formed on the second antiferromagnetic layers and on the extending portions of the ferromagnetic layers. It is thus possible to improve reproduced output, and suppress widening of an effective reproducing track width to appropriately suppress the occurrence of side reading.
    Type: Grant
    Filed: May 6, 2003
    Date of Patent: October 16, 2007
    Assignee: Alps Electric Co., Ltd
    Inventors: Naoya Hasegawa, Eiji Umetsu
  • Patent number: 7283334
    Abstract: A magnetic head having a spin valve sensor that is fabricated utilizing an Al2O3, NiMnO, NiFeCr seed layer upon which a typical PtMn spin valve sensor layer structure is subsequently fabricated. The preferred embodiment fabrication process of the NiFeCr layer includes the overdeposition of the layer to a first thickness of from 15 ? to 45 ? followed by the etching back of the seed layer of approximately 5 ? to approximately 15 ? to its desired final thickness of approximately 10 ? to 40 ?. The Cr at. % composition in the NiFeCr layer is preferably from approximately 35 at. % to approximately 46 at. %. The crystal structure of the surface of the etched back NiFeCr layer results in an improved crystal structure to the subsequently fabricated spin valve sensor layers, such that the fabricated spin valve exhibits increased ?R/R and reduced coercivity.
    Type: Grant
    Filed: June 15, 2006
    Date of Patent: October 16, 2007
    Assignee: International Business Machines Corporation
    Inventor: Mustafa Pinarbasi
  • Publication number: 20070230067
    Abstract: A CPP type magnetoresistance effect device having a synthetic ferri-pinned spin valve structure including a buffer layer, pinned ferromagnetic layer, nonmagnetic metal intermediate layer, and free ferromagnetic layer and having a free ferromagnetic layer made a specific composition of CoFeAl or CoMnAl, the buffer layer comprising an amorphous metal bottom layer and a nonmagnetic metal top layer. This magnetoresistance effect device increases the output ?RA, reduces the coercivity Hc and the amount of shift Hin from a zero magnetic field to increase the sensitivity, and increases the magnetic field Hua of the resistance half point to increase the pin stability. A magnetic head, magnetic recording system, and magnetic random access memory using this magnetoresistance effect device are also disclosed.
    Type: Application
    Filed: August 18, 2006
    Publication date: October 4, 2007
    Applicant: FUJITSU LIMITED
    Inventors: Arata Jogo, Yutaka Shimizu
  • Publication number: 20070230069
    Abstract: A magnetoresistive element has a magnetization pinned layer including a magnetic film a magnetization direction of which is substantially pinned in one direction, a magnetization free layer including a magnetic film a magnetization direction of which is varied depending on an external magnetic field, a composite spacer layer interposed between the magnetization pinned layer and the magnetization free layer, and including an insulating portion and a magnetic metal portion, and a pair of electrodes configured to supply a sense current in a direction perpendicular to planes of the magnetization pinned layer, the composite spacer layer and the magnetization free layer, in which the magnetic film included in the magnetization pinned layer and being in contact with the composite spacer layer has a bcc structure.
    Type: Application
    Filed: March 26, 2007
    Publication date: October 4, 2007
    Applicants: Kabushiki Kaisha Toshiba, TDK Corporation
    Inventors: Hiromi Fuke, Susumu Hashimoto, Masayuki Takagishi, Hitoshi Iwasaki
  • Publication number: 20070223150
    Abstract: A magnetoresistive effect element includes a magnetization fixed layer including a first crystal grain, having a magnetization direction which is fixed substantially in one direction, a spacer layer arranged on the magnetization fixed layer and having an insulating layer and a metal conductor penetrating the insulating layer, and a magnetization free layer including a second crystal grain, arranged on the spacer layer to oppose the metal conductor and having a magnetization direction which changes corresponding to an external magnetic field.
    Type: Application
    Filed: October 13, 2006
    Publication date: September 27, 2007
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Yoshinari Kurosaki, Hiromi Yuasa, Yoshihiko Fuji, Hitoshi Iwasaki
  • Patent number: 7274542
    Abstract: A magnetic sensor includes a spacer having at least a nonmagnetic metal layer inserted between the upper shield layer and the longitudinal bias layers or between the upper shield layer and the longitudinal bias layers plus the magnetoresistive film, the shortest distance between the longitudinal bias layers and the free layer of the magnetoresistive film is set smaller than the shortest distance between the longitudinal bias layers and the upper shield layer, and this arrangement ensures that the amount of magnetic flux entering the magnetoresistive film from the longitudinal bias layers is larger than that absorbed by the upper shield layer, thus realizing a magnetic sensor whose Barkhausen noise is suppressed.
    Type: Grant
    Filed: February 5, 2003
    Date of Patent: September 25, 2007
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Taku Shintani, Katsuro Watanabe, Masahiko Hatatani, Kikuo Kusukawa
  • Patent number: 7270896
    Abstract: A magnetic tunneling element is constructed from a MgO or Mg—ZnO tunnel barrier and an amorphous magnetic layer in proximity with the tunnel baffler. The amorphous magnetic layer includes Co and at least one additional element selected to make the layer amorphous. Magnetic tunnel junctions formed from the amorphous magnetic layer, the tunnel barrier, and an additional ferromagnetic layer have tunneling magnetoresistance values of up to 200% or more.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: September 18, 2007
    Assignee: International Business Machines Corporation
    Inventor: Stuart Stephen Papworth Parkin
  • Patent number: 7268981
    Abstract: In one illustrative example, a spin valve sensor includes a free layer structure; an anti-parallel (AP) pinned layer structure which includes at least a first AP pinned layer; and a non-magnetic electrically conductive spacer layer formed between the free layer structure and the AP pinned layer structure. First and second antiferromagnetic (AFM) pinning layer structures for magnetically pinning the first AP pinned layer are formed in end regions but are absent from its central region. Edges of each AFM pinning layer structure may be separated by a distance DA from the sensor edges. The first AP pinned layer is formed in both the central region and the end regions so as to be in contact with the first and second AFM pinning layer structures. Advantageously, adequate pinning properties are exhibited in a sensor which provides the benefits of a self-pinned sensor (e.g. a reduced sensor profile in the central region).
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: David Eugene Heim
  • Patent number: 7268982
    Abstract: A current perpendicular to plane (CPP) giant magnetoresistive (GMR) sensor having an antiparallel coupled (AP coupled) pinned layer structure wherein the pinning layer have a greatly reduced negative contribution to dR. The pinned layer structure includes a first a first set of magnetic layers such as CoFe and a second set of magnetic layer comprising CoFeV that are antiparallel coupled with the first set of magnetic layers. The magnetic layers of the pinned layer structure alternate between a one of the first set of magnetic layers (eg. CoFe) and one of the second set of magnetic layers (CoFeV). The magnetic layers of the first set contribute to the GMR of the sensor and provide a positive magnetostriction that assists with the pinning of the pinned layer structure. The magnetic layers of the second set contribute pinning, but do not contribute to GMR.
    Type: Grant
    Filed: October 21, 2004
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7268984
    Abstract: A CPP magnetic detecting element having a pinned magnetic layer whose magnetization is fixed by its uniaxial anisotropy in a structure that CIP magnetic detecting elements do not allow. In the CPP magnetic detecting element, the upper and lower surfaces of a pinned magnetic layer having an artificial ferrimagnetic structure are disposed between a magnetostriction-enhancing layer made of a nonmagnetic metal and a nonmagnetic material layer having a higher lattice constant than Cu. CPP magnetic detecting elements allow this structure without reducing the variation in resistance per unit area ?R·A. Thus, the magnetostriction coefficient of the pinned magnetic layer can be increased from above and below, thereby more firmly fixing the magnetization of the pinned magnetic layer.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: September 11, 2007
    Assignee: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Masamichi Saito, Eiji Umetsu
  • Patent number: 7268979
    Abstract: The present invention overcomes the drawbacks and limitations described above by providing a magnetic head having a free layer, an antiferromagnetic layer spaced apart from the free layer, and an antiparallel (AP) pinned layer structure positioned between the free layer and the antiferromagnetic layer and having a net magnetic moment equal to about zero. The antiferromagnetic layer provides a coercivity that enhances pinning of the AP pinned layer structure.
    Type: Grant
    Filed: July 2, 2003
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7268986
    Abstract: A double tunnel junction TMR magnetoresistive sensor having first and second magnetic free layers separated by a self pinned magnetic layer. The self pinned magnetic layer is separated from the first and second free layers by thin barrier layers. The pinned layer magnetization is pinned without the need for exchange pinning with an adjacent layer of antiferromagnetic layer.
    Type: Grant
    Filed: March 31, 2004
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7268980
    Abstract: A magnetic head has a read sensor including a free layer, a spacer layer and a number of self-pinned layers. These self-pinned layers include interleaved layers of ferromagnetic material and non-magnetic metal. The self-pinned layers are pinned through magnetostrictive anisotropy, and preferably have a net magnetic moment which is approximately zero.
    Type: Grant
    Filed: February 11, 2004
    Date of Patent: September 11, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7268983
    Abstract: A magnetic sensing device is presented that has a multilayer material with a pinned magnetic layer, a nonmagnetic material layer, and a free magnetic layer. The pinned magnetic layer is a composite with a nonmagnetic intermediate layer and magnetic thin-film layers separated from each other by the nonmagnetic intermediate layer. A first nonmagnetic magnetostriction-enhancing layer is on the pinned magnetic layer and contacts a first thin-film layer placed farthest from the nonmagnetic material layer. At least one of the magnetic thin-film layers has a composite structure with a second nonmagnetic magnetostriction-enhancing layer and magnetic layers separated from each other by the second magnetostriction-enhancing layer. All of the magnetic layers are magnetized in the same direction antiparallel to the adjacent magnetic thin-film layer. At least some crystals of the first and second magnetostriction-enhancing layers and the first thin-film layer/magnetic layers are epitaxial or heteroepitaxial.
    Type: Grant
    Filed: June 20, 2005
    Date of Patent: September 11, 2007
    Assignee: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Masamichi Saito, Eiji Umetsu
  • Patent number: 7265948
    Abstract: No related magnetoresistive multi-layered films made from a metal magnetic film provide sufficient reproducing output power. A high-polarized layer with a thickness of 10 nm or less is formed as a Fe-rich Fe—O layer in contact with the interface of a non-magnetic intermediate layer and the resulting layers are heat treated to form a multi-layered film of ferromagnetic Fe—O layers, achieving a magnetoresistive element having high magnetoresistance.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: September 4, 2007
    Assignee: Hitachi Global Storage Technologies Japan, Ltd.,
    Inventors: Hiroyuki Hoshiya, Susumu Soeya, Kenichi Meguro
  • Patent number: 7265946
    Abstract: A self pinned CPP GMR sensor having an AP1 layer extending beyond the track width of the sensor and a multilayer AP2 layer including layers of CoFe interspersed with thin non-magnetic layers such as Cu.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: September 4, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Publication number: 20070201169
    Abstract: An advantage of the application is to provide a magnetoresistance element capable of increasing a plateau magnetic field Hp1 while maintaining high ?RA. A magnetic layer 4c1 adjacent to a non-magnetic material layer 5 in a second fixed magnetic layer 4c constituting the fixed magnetic layer 4 is formed of a first Heusler-alloy layer represented by Co2x(Mn(1-z)Fez)x?y (where the element a is any one element of 3B group, 4B group, and 5B group, x and y all are in the unit of at %, 3x+y=100 at %). Additionally, the content y is in the range of 20 to 30 at % and a Fe ratio z in MnFe is in the range of 0.2 to 0.8. Accordingly, the plateau magnetic field Hp1 may increase while maintaining high ?RA.
    Type: Application
    Filed: February 16, 2007
    Publication date: August 30, 2007
    Applicant: ALPS ELECTRIC CO., LTD.
    Inventors: Yosuke Ide, Ryo Nakabayashi, Masamichi Saito, Naoya Hasegawa
  • Patent number: 7256971
    Abstract: A CPP-GMR spin value sensor structure with an improved MR ratio and increased resistance is disclosed. All layers except certain pinned layers, copper spacers, and a Ta capping layer are oxygen doped by adding a partial O2 pressure to the Ar sputtering gas during deposition. Oxygen doped CoFe free and pinned layers are made slightly thicker to offset a small decrease in magnetic moment caused by the oxygen dopant. Incorporating oxygen in the MnPt AFM layer enhances the exchange bias strength. An insertion layer such as a nano-oxide layer is included in one or more of the free, pinned, and spacer layers to increase interfacial scattering. The thickness of all layers except the copper spacer may be increased to enhance bulk scattering. A CPP-GMR single or dual spin valve of the present invention has up to a threefold increase in resistance and a 2 to 3% increase in MR ratio.
    Type: Grant
    Filed: March 9, 2004
    Date of Patent: August 14, 2007
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 7248447
    Abstract: A self pinned magnetoresistive sensor having an anitparallel coupled pinned layer structure including a high coercivity (high Hc) layer of TbCo.
    Type: Grant
    Filed: May 5, 2004
    Date of Patent: July 24, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill