Detail Of Free Layer Or Additional Film For Affecting Or Biasing The Free Layer Patents (Class 360/324.12)
  • Patent number: 7580230
    Abstract: A magnetoresistive sensor having a shape enhanced pinning and a flux guide structure. First and second hard bias layers and lead layers extend from the sides of a sensor stack. The hard bias layers and leads have a stripe height that is smaller than the stripe height of a free layer, resulting in a free layer that extends beyond the back edge of the lead and hard bias layer. This portion of the free layer that extends beyond the back edge of the leads and hard bias layers provides a back flux guide. Similarly, the sensor may have a free layer that extends beyond the front edge of the lead and hard bias layers to provide a front flux guide. The pinned layer extends significantly beyond the back edge of the free layer, providing the pinned layer with a strong shape enhanced magnetic anisotropy.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: August 25, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Patent number: 7580228
    Abstract: A CPP MR sensor includes a sense layer with a smoothly curving perimeter, lowering edge effects and Barkhausen noise. For example, a circular or oval CPP sensor stack can be defined, or the sensor layers can be milled to have a tapered track width that is narrower adjacent media facing surface, to avoid sharp corners at that media facing surface after lapping which has been monitored for resistance change to terminate at the correct plane. Single domain sensor layers, such as free, pinned, and bias layers, can be produced with this technique, increasing stability, lowering noise and increasing magnetoresistance of the sensor. A smoother rotation of the free layer magnetic moment, and a more linear signal, can also be provided. An antiferromagnetic bias layer can also be eliminated due to the reduced edge effects of the free layer.
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: August 25, 2009
    Inventor: Mark A. Lauer
  • Patent number: 7580231
    Abstract: A magneto-resistive element has a pinned layer, a free layer, and a spacer layer which is sandwiched between the pinned layer and the free layer. The spacer layer is made of copper. The magneto-resistive element is configured such that sense current is applied in a direction that is perpendicular to layer surfaces. The free layer has: a nonmagnetic layer that includes copper as a main component; and ternary alloy layers each including cobalt (Co), iron (Fe), and nickel (Ni), the ternary alloy layers being disposed on both sides of the nonmagnetic layer. The ternary alloy layer includes nickel and iron at a composition ratio in which a ratio x of an atomic percentage of nickel to a total atomic percentage of nickel and iron is 27%?x?45%.
    Type: Grant
    Filed: October 27, 2006
    Date of Patent: August 25, 2009
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Tomohito Mizuno
  • Publication number: 20090195941
    Abstract: A magnetic sensor with increased sensitivity, lower noise, and improved frequency response is described. The sensor's free layer is ribbon shaped and is closely flanked at each long edge by a ribbon of magnetically soft, high permeability material. This side pattern absorbs external field flux, concentrating it to flow into the sensor's edges to promote larger MR sensor magnetization rotation.
    Type: Application
    Filed: February 5, 2008
    Publication date: August 6, 2009
    Inventors: Yuchen Zhou, Yimin Guo
  • Patent number: 7570462
    Abstract: A read sensor with a uniform longitudinal bias (LB) stack is proposed. The read sensor is a giant magnetoresistance (GMR) sensor used in a current-in-plane (CIP) or a current-perpendicular-to-plane (CPP) mode, or a tunneling magnetoresistance (TMR) sensor used in the CPP mode. The transverse pinning layer of the read sensor is made of an antiferromagnetic Pt—Mn, Ir—Mn or Ir—Mn—Cr film. In one embodiment of this invention, the uniform LB stack comprises a longitudinal pinning layer, preferable made of an antiferromagnetic Ir—Mn—Cr or Ir—Mn film, in direct contact with and exchange-coupled to sense layers of the read sensor. In another embodiment of the present invention, the uniform LB stack comprises the Ir—Mn—Cr or Ir—Mn longitudinal pinning layer exchange coupled to a ferromagnetic longitudinal pinned layer, and a nonmagnetic antiparallel-coupling spacer layer sandwiched between and the ferromagnetic longitudinal pinned layer and the sense layers.
    Type: Grant
    Filed: May 28, 2008
    Date of Patent: August 4, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Tsann Lin
  • Patent number: 7570461
    Abstract: A magnetic sensor includes a sensor stack having a sensing layer. A first biasing structure having a first magnetization vector is positioned adjacent to the sensor stack to produce a biasing field that biases the sensing layer. A second biasing structure having a second magnetization vector is positioned within the sensor stack relative to the sensing layer to counter the biasing field at a center of the sensing layer.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: August 4, 2009
    Assignee: Seagate Technology LLC
    Inventor: Victor B. Sapozhnikov
  • Patent number: 7567413
    Abstract: There is provided a magnetic detecting element by devising a configuration of a free magnetic layer or a pinned magnetic layer, and a method of manufacturing a magnetic detecting element. The free magnetic layer is formed to have a three-layered structure of a CoMnZ alloy layer, a CoMnX alloy layer, and a CoMnZ alloy layer. The CoMnX alloy layer is formed of a metal compound whose compositional formula is represented by CoaMnbXc (X is one or more elements selected from a group of Ge, Sn, Ga, and Sb, a, b, and c are atomic percent, and a+b+c=100 atomic percent). The CoMnZ alloy layer is formed of a metal compound whose compositional formula is represented by CodMneZf (Z is Al or Si, d, e, and f are atomic percent, and d+e+f=100 atomic percent).
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: July 28, 2009
    Assignee: TDK Corporation
    Inventors: Yosuke Ide, Masamichi Saito, Masahiko Ishizone, Naoya Hasegawa
  • Patent number: 7567412
    Abstract: A magnetic sensing element includes a free magnetic layer having a three-layer structure including a first enhancement layer in contact with a nonmagnetic material layer, a second enhancement layer, and a low-coercivity layer. The second enhancement layer has a lower magnetostriction coefficient ? than the first enhancement layer. If such an enhancement layer having a bilayer structure is used, rather than a known monolayer structure, and the second enhancement layer has a lower magnetostriction coefficient ? than the first enhancement layer, the rate of change in magnetoresistance of the magnetic sensing element can be increased with no increase in the magnetostriction coefficient ? of the free magnetic layer.
    Type: Grant
    Filed: October 26, 2005
    Date of Patent: July 28, 2009
    Assignee: Alps Electric Co., Ltd.
    Inventors: Ryo Nakabayashi, Eiji Umetsu, Kazuaki Ikarashi, Fumihito Koike, Naoya Hasegawa
  • Patent number: 7564661
    Abstract: A magnetic sensing element which allows a high reproduction output and reduction in asymmetry of reproduction waveform to become mutually compatible, as well as a method for manufacturing the same, is provided. In the inside of a second pinned magnetic layer and a free magnetic layer, the atomic percentage of an element Z is decreased in a region close to a non-magnetic material layer. Consequently, the ferromagnetic coupling magnetic field due to magnetostatic coupling (topological coupling) between the pinned magnetic layer and the free magnetic layer can be reduced. At the same time, in a region at a distance from the non-magnetic material layer, the atomic percentage of an element Z is increased, a spin-dependent bulk scattering coefficient is increased, and a product of the amount of change in magnetic resistance and the element area of the magnetic sensing element can be maintained at a high level.
    Type: Grant
    Filed: February 13, 2006
    Date of Patent: July 21, 2009
    Assignee: TDK Corporation
    Inventors: Yosuke Ide, Masamichi Saito, Masahiko Ishizone, Naoya Hasegawa
  • Patent number: 7561385
    Abstract: A magneto-resistive element comprising a free layer having two ferromagnetic layers having a nonmagnetic layer interposed therebetween are coupled with each other in an anti-ferromagnetic manner, a difference between an absolute value of a total of magnetizations of at least one ferromagnetic layer in which the magnetization direction is a first direction and an absolute value of a total of magnetizations of at least one ferromagnetic layer in which the magnetization direction is a second direction which is opposite to the first direction is equal to or smaller than 5×10?15 emu, and planes parallel to a substrate of the ferromagnetic layers are smaller as the planes are distant from the substrate.
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: July 14, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shiho Nakamura, Shigeru Haneda
  • Patent number: 7558028
    Abstract: A magnetic head including a CPP GMR read sensor that includes a reference layer, a free magnetic layer and a spacer layer that is disposed between them, where the free magnetic layer and the reference magnetic layer are each comprised of Co2MnX where X is a material selected from the group consisting of Ge, Si, Al, Ga and Sn, and where the spacer layer is comprised of a material selected from the group consisting of Ni3Sn, Ni3Sb, Ni2LiGe, Ni2LiSi, Ni2CuSn, Ni2CuSb, Cu2NiSn, Cu2NiSb, Cu2LiGe and Ag2LiSn. Further embodiments include a dual spin valve sensor where the free magnetic layers and the reference layers are each comprised of Heusler alloys. A further illustrative embodiment includes a laminated magnetic layer structure where the magnetic layers are each comprised of a ferromagnetic Heusler alloy, and where the spacer layers are comprised of a nonmagnetic Heusler alloy.
    Type: Grant
    Filed: November 16, 2005
    Date of Patent: July 7, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew Joseph Carey, Jeffrey Robinson Childress, Stefan Maat
  • Patent number: 7558029
    Abstract: There is provided a magnetic detecting element having a large ?RA. A free magnetic layer has a three layer structure in which a CoFe layer, an NiaFeb alloy layer (where a and b are represented by at %, 0?a?25, and a+b=100), and a CoFe layer are laminated from the bottom. If the at % of Ni in an NiFe alloy that exists in the free magnetic layer is in this range, a spin-dependent bulk scattering coefficient ? increases, and the product ?RA of the resistance variation of the magnetic detecting element and the area of the element can be made increased.
    Type: Grant
    Filed: February 27, 2006
    Date of Patent: July 7, 2009
    Assignee: TDK Corporation
    Inventors: Yosuke Ide, Masamichi Saito, Masahiko Ishizone, Naoya Hasegawa
  • Publication number: 20090168271
    Abstract: Tunneling magnetoresistive (TMR) elements and associated methods of fabrication are disclosed. In one embodiment, the TMR element includes a ferromagnetic pinned layer structure, a tunnel barrier layer, and a free layer structure comprised of dual-layers. The free layer structure includes a first free layer and a second amorphous free layer. The magnetic thicknesses of the first free layer and the second amorphous free layer of the dual layer structure differ to provide improved TMR performance. In one example, the first free layer may have a magnetic thickness that is less than 40% of the total magnetic thickness of the free layer structure.
    Type: Application
    Filed: December 27, 2007
    Publication date: July 2, 2009
    Inventors: Daniele Mauri, Satoshi Shigematsu, Alexander M. Zeltser
  • Patent number: 7554757
    Abstract: A write head for a magnetic storage system energizes a write coil for a plurality of bit intervals and selectively shutters the magnetic field to alter a magnetic domain of a magnetic storage medium for each bit interval. The position of the shutter may be controlled using a micro-electro mechanical system. Magnetic pole segments provide a loop between the write coil and the magnetic storage medium. Magnetic shielding on the shutter mechanisms controls the reflection of the magnetic fields. In a rewritable magnetic storage system, a first write coil generates a positive magnetic field and a second write coil generates a negative magnetic field. A shutter is associated with each write coil to selectively allow the positive or negative magnetic fields to alter the magnetic domain of the magnetic storage medium. The positive or negative magnetic fields can alter the magnetic domain in a collocated region of the magnetic storage medium to avoid jitter.
    Type: Grant
    Filed: November 21, 2003
    Date of Patent: June 30, 2009
    Assignee: Agere Systems Inc.
    Inventors: Jonathan H. Fischer, Roger A. Fratti, John T. Rehberg
  • Publication number: 20090161269
    Abstract: A magnetoresistive sensor having an improved hard bias stabilization structure. The sensor includes a hard bias layer that is formed on a surface that has been treated to form it with an anisotropic texture that induces a magnetic anisotropy oriented parallel with the air bearing surface. This magnetic anisotropy is further aided by a shape induced magnetic anisotropy caused by configuring the hard bias layers to have a width parallel with the air bearing surface that is larger than a stripe height of the hard bias layer measured perpendicular to the air bearing surface.
    Type: Application
    Filed: December 21, 2007
    Publication date: June 25, 2009
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7551408
    Abstract: Both end portions of a magneto-resistive effect film form a junction taper shape and, at both end portions forming the junction taper shape, a pair of bias magnetic field applying layers are disposed via underlayers for applying a longitudinal bias magnetic field to a soft magnetic layer. Each of the underlayers is formed by a thin film made of at least one element selected from a group of Ru, Ti, Zr, Hf, and Zn or an alloy thin film containing, as a main component, at least one element selected from the group. Each of the bias magnetic field applying layers formed on the underlayers is formed by a hard magnetic layer and has a thickness of 200 ? or less (not including zero).
    Type: Grant
    Filed: April 12, 2005
    Date of Patent: June 23, 2009
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Kosuke Tanaka, Tomoaki Shimizu
  • Patent number: 7551409
    Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor has an improved free layer structure that includes a first ferromagnetic interface layer on the sensor's nonmagnetic spacer layer, a first electrically conductive interlayer on the first interface layer, a central ferromagnetic NiFe alloy free layer on the first interlayer, a second electrically conductive interlayer on the central free layer, and a second ferromagnetic interface layer on the second interlayer. The first ferromagnetic interface layer, central ferromagnetic free layer, and second ferromagnetic interface layer are ferromagnetically coupled together across the electrically conductive interlayers so their magnetization directions remain parallel. The free layer structure may be used in single or dual CPP sensors and in spin-valve or tunneling MR sensors.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: June 23, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
  • Patent number: 7548400
    Abstract: The thin-film magnetic head of the present invention comprises an MR sensor wherein a first ferromagnetic layer in which a magnetization direction is fixed with respect to external magnetic fields, a non-magnetic intermediate layer, and a second ferromagnetic layer in which a magnetization direction changes with respect to the external magnetic fields are stacked, and wherein a sense current flows substantially parallel to the stacked layer surface.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: June 16, 2009
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Noriaki Kasahara, Kazuki Sato, Takayasu Kanaya
  • Patent number: 7542248
    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: November 23, 2007
    Date of Patent: June 2, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuzo Kamiguchi, Hiromi Yuasa, Tomohiko Nagata, Hiroaki Yoda
  • Patent number: 7542249
    Abstract: Two embodiments of a GMR sensor of the bottom spin valve (BSV) spin filter spin valve (SFSV) type are provided, together with methods for their fabrication. In one embodiment, the sensor has an ultra thin (<20 angstroms) single free layer and a composite high-conductance layer (HCL), providing high output, low coercivity and positive magnetostriction. In a second embodiment, the sensor has a composite free layer and a single HCL, also having high output, low coercivity and positive magnetostriction. The sensors are capable of reading densities exceeding 60 Gb/in2.
    Type: Grant
    Filed: November 8, 2005
    Date of Patent: June 2, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 7538989
    Abstract: In a magnetic tunnel junction (MTJ) device having a pinned layer and upper and lower free sublayers, to avoid loss in tunnel magnetoresistance, etching or milling of the free sublayer materials is stopped in the lower free sublayer. The upper free sublayer may be softer and thicker than the lower free sublayer to promote this, and may be doped to reduce its magnetization while maintaining physical thickness. The lower free sublayer can be made of CoFe and the upper free sublayer can made of NiFe and a dopant such as Mo or Rh.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: May 26, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7536772
    Abstract: A method is given for the manufacture of a bottom spin valve (BSV) spin filter spin valve (SFSV) type read sensor. The sensor has a composite, ultra-thin (<20 Angstroms) laminated free layer formed as a Cu high conductance layer (HCL) between two layers of CoFe. A second HCL is formed as a layer of Ru on the composite free layer. By adjusting the thicknesses of the two HCL's, the free layer will have low coercivity and tunable magnetostriction. The sensor is capable of reading densities exceeding 60 Gb/in2.
    Type: Grant
    Filed: November 8, 2005
    Date of Patent: May 26, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 7535683
    Abstract: A magnetoresistive head and a fabricating method thereof accomplishing high sensitivity and low noise are provided even if track width narrowing makes progress. In one embodiment, a pinned layer includes a laminate which includes at least two magnetic layers and where adjacent magnetic layers are coupled antiferromagnetically to each other, and a mechanism to apply a longitudinal biasing field to a free layer is made to function by laminating a nonmagnetic separate layer/longitudinal biasing layer/antiferromagnetic layer connecting the free layer and opposite a nonmagnetic conductive layer (or nonmagnetic tunneling barrier layer). Controlling a magnetization direction of the longitudinal biasing layer which bears application of a longitudinal biasing field to the pinned layer and free layer is achieved by annealing carried out while applying a magnetic field in a track width direction and applying a magnetic field at room temperature.
    Type: Grant
    Filed: October 29, 2004
    Date of Patent: May 19, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Kenichi Meguro, Kouichi Nishioka, Masahiko Hatatani, Chiseki Haginoya
  • Patent number: 7532442
    Abstract: Magnetoresistive (MR) elements having pinning layers formed from a permanent magnetic material are disclosed. An MR element of the invention includes a first pinning layer, a first pinned layer, a first spacer/barrier layer, a free layer, a second spacer/barrier layer, a second pinned layer, and a second pinning layer. One of the first pinning layer or the second pinning layer is formed from a permanent magnetic material, such as CoPt or CoPtCr. The other of the first pinning layer or the second pinning layer is formed from an antiferromagnetic (AFM) material, such as IrMn or PtMn.
    Type: Grant
    Filed: September 19, 2005
    Date of Patent: May 12, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal S. Gill
  • Patent number: 7530160
    Abstract: A method for manufacturing a magnetoresistive sensor having improved free layer biasing and track width control. The method includes forming a ferromagnetic pinned layer, and depositing a ferromagnetic film thereover. A layer of Ta is deposited over the ferromagnetic film and a mask is formed over an active sensor area. A reactive ion etch process is performed to remove selected portions of said Ta layer. An etch is then performed to remove selected portions of the ferromagnetic film in unmasked areas and a ferromagnetic refill material is deposited.
    Type: Grant
    Filed: September 5, 2007
    Date of Patent: May 12, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7530158
    Abstract: A method is disclosed for fabricating a CPP read head for a magnetic disk drive having an electrical isolation layer. The method includes providing a first shield layer, depositing a sensor stack on the first shield layer, a CMP stop layer is deposited on the sensor stack, and a release layer is deposited a on the CMP stop layer. Photoresist material containing Si is deposited on the release layer, and the photoresist material is then patterned and then oxidized by Reactive Ion Etching to form a high temperature photomask. The electrical isolation layer is then deposited to surround the sensor stack using a high temperature deposition process. The read head is then continued as either an in-stack bias sensor with ‘draped shield’ variation, or a hard bias stabilization variation.
    Type: Grant
    Filed: April 19, 2005
    Date of Patent: May 12, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Satoru Araki, Robert Stanley Beach, Ying Hong, Thomas L. Leong, Timothy J. Minvielle, Howard Gordon Zolla
  • Patent number: 7529067
    Abstract: Although it is known that exchange bias can be utilized in abutted junctions for longitudinal stabilization, a relatively large moment is needed to pin down the sensor edges effectively. Due to the inverse dependence of the exchange bias on the magnetic layer thickness, a large exchange bias has been difficult to achieve by the prior art. This problem has been solved by introducing a structure in which the magnetic moment of the bias layer has been approximately doubled by pinning it from both above and below through exchange with antiferromagnetic layers. Additionally, since the antiferromagnetic layer is in direct abutted contact with the free layer, it acts directly to help stabilize the sensor edge, which is an advantage over the traditional magnetostatic pinning that had been used.
    Type: Grant
    Filed: March 14, 2006
    Date of Patent: May 5, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Yun-Fei Li, Hui-Chuan Wang, Chyu-Jiuh Torng, Cherng-Chyi Han, Mao-Min Chen
  • Publication number: 20090109580
    Abstract: A magnetic field detecting element comprises; a stack including an upper magnetic layer and a lower magnetic layer, and a non-magnetic intermediate layer sandwiched between said upper magnetic layer and said lower magnetic layer, wherein magnetization of said upper magnetic layer and said lower magnetic layer changes in accordance with an external magnetic field; an upper shield electrode layer and a lower shield electrode layer which is provided to sandwich said stack therebetween in a direction of the stacking of said stack, wherein said upper shield electrode layer and said lower shield electrode layer supply sense current in the direction of stacking, and magnetically shield said stack; a bias magnetic layer which is provided on a surface of said stack opposite to an air bearing surface, and wherein said bias magnetic layer applies a bias magnetic field to said upper magnetic layer and said lower magnetic layer in a direction perpendicular to the air bearing surface; and insulating layers which are provid
    Type: Application
    Filed: October 26, 2007
    Publication date: April 30, 2009
    Inventors: Toshiyuki AYUKAWA, Daisuke MIYAUCHI, Koji SHIMAZAWA, Takahiko MACHITA
  • Publication number: 20090109581
    Abstract: There are provided a magnetoresistance effect element, a magnetic head, a magnetic head assembly and a magnetic recording system, which have high sensitivity and high reliability. The magnetoresistance effect element has two ferromagnetic layers, a non-magnetic layer provided between the ferromagnetic layers, and a layer containing an oxide or nitride as a principal component, wherein the layer containing the oxide or nitride as the principal component contains a magnetic transition metal element which does not bond to oxygen and nitrogen and which is at least one of Co, Fe and Ni.
    Type: Application
    Filed: December 31, 2008
    Publication date: April 30, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hideaki FUKUZAWA, Katsuhiko Koi, Hiromi Fuke, Hiroshi Tomita, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 7525776
    Abstract: A magnetoresistive element has a magnetization pinned layer a magnetization direction of which is substantially pinned in one direction, a magnetization free layer a magnetization direction of which varies depending on an external field, and a spacer layer including an insulating layer provided between the magnetization pinned layer and the magnetization free layer and current paths penetrating the insulating layer, the magnetization pinned layer or magnetization free layer located under the spacer layer comprising crystal grains separated by grain boundaries extending across a thickness thereof, in which, supposing that an in-plane position of one end of each of the crystal grains is set to 0 and an in-plane position of a grain boundary adjacent to the other end of the crystal grain is set to 100, the current path corresponding the crystal grain is formed on a region in a range between 20 and 80 of the in-plane position.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: April 28, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Katsuhiko Koui, Hitoshi Iwasaki
  • Patent number: 7524381
    Abstract: A method for controlling magnetostriction in a free layer of a magnetoresistive sensor. A pinned layer structure is deposited and then a spacer layer, preferably Cu is deposited. Oxygen is introduced into the spacer layer. The oxygen can be introduced either during the deposition of the spacer layer or after the spacer layer has been deposited. A free layer structure is then deposited over the spacer layer. A capping layer such as Ta can be deposited over the free layer structure. The sensor is annealed to set the magnetization of the pinned layer. In the process of annealing the sensor the oxygen migrates out of the spacer. After annealing, no significant amount of oxygen is present in either the spacer layer or the free layer structure, and only trace amounts of oxygen are present in the Ta capping layer.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: April 28, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ben Long Thai, Dulip Ajantha Welipitiya
  • Patent number: 7525774
    Abstract: A laser diode capable of being easily mounted and a laser diode device in which the laser diode is mounted are provided. A hole is disposed in a semiconductor layer, and a p-type electrode and an n-type semiconductor layer are electrically connected to each other by a bottom portion (a connecting portion) of the hole. Thereby, the p-type electrode has the same potential as the n-type semiconductor layer, and a saturable absorption region is formed in a region corresponding to a current path. Light generated in a gain region (not shown) is absorbed in the saturable absorption region so as to be converted into a current. The current is discharged to a ground via the p-side electrode and the bottom portion, an interaction between the saturable absorption region and the gain region is initiated, and thereby self-oscillation can be produced.
    Type: Grant
    Filed: September 19, 2005
    Date of Patent: April 28, 2009
    Assignee: Sony Corporation
    Inventors: Yutaka Soda, Masaaki Sekine
  • Publication number: 20090103215
    Abstract: MR devices and associated methods of fabrication are disclosed. An MR device includes an MR element and a bias structure on either side of the MR element for biasing a free layer of the MR element. The bias structure includes an amorphous buffer layer, a first seed layer formed from Cr, a second seed layer formed from a non-magnetic Cr alloy, and a hard bias magnetic layer. The second seed layer formed from the non-magnetic Cr alloy is formed between the Cr seed layer and the hard bias magnetic layer. An example of a non-magnetic Cr alloy is Chromium-Molybdenum (CrMo).
    Type: Application
    Filed: December 30, 2008
    Publication date: April 23, 2009
    Inventors: James M. Freitag, Mustafa M. Pinarbasi
  • Patent number: 7522389
    Abstract: A magnetoresistance effect element is composed of a first ferromagnetic layer, a second ferromagnetic layer, and at least one nano-contact portion formed between the first and second ferromagnetic layers, which are formed on the same plane on a substrate. The nano-contact portion has a maximum dimension of not more than Fermi length of a material constituting the nano-contact portion. A permanent magnet layer or in-stack bias layer may be further formed on the first and/or second ferromagnetic layer.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: April 21, 2009
    Assignee: TDK Corporation
    Inventors: Rachid Sbiaa, Isamu Sato
  • Patent number: 7522391
    Abstract: A magnetoresistive sensor having an in stack bias structure and a pinned layer having shape enhanced anisotropy. The sensor may be a partial mill design wherein the track width of the sensor is defined by the width of the free layer and the pinned layers extend beyond the trackwidth of the sensor. The sensor has an active area defined by the stripe height of the free layer. The pinned layer extends beyond the stripe height defined by the free layer, thus providing the pinned layer with the shape enhanced anisotropy. The pinned layer structure can be pinned by exchange coupling with a layer of antiferromagnetic material (AFM) layer, with pinning robustness being improved by the shape enhanced anisotropy, or can be a self pinned structure which is pinned by a combination of magnetostriction, AP coupling and shape enhanced anisostropy.
    Type: Grant
    Filed: December 14, 2005
    Date of Patent: April 21, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Publication number: 20090097170
    Abstract: A ferromagnetic tunnel junction element is a magnetoresistance effect element wherein an electric resistance varies in accordance with a magnetic field applied. The ferromagnetic tunnel junction element includes a pinned layer wherein at least a part of a magnetization direction is held, and an insulation layer formed on the pinned layer, creating an energy barrier that electrons can flow through by a tunnel effect. A first free layer made of a first ferromagnetic material containing boron atoms, is formed on the insulation layer. In the first free layer, a direction of the magnetization switches under an influence of an external magnetic field. A second free layer made of a first ferromagnetic material containing boron atoms, is formed on the first free layer. The direction of magnetization of the second free layer switches under the influence of the external magnetic field, exchanging and coupling with the first free layer.
    Type: Application
    Filed: September 2, 2008
    Publication date: April 16, 2009
    Applicant: FUJITSU LIMITED
    Inventors: Masashige Sato, Shinjiro Umehara, Takahiro Ibusuki
  • Patent number: 7518835
    Abstract: A method and system for providing a magnetic element are disclosed. The method and system include providing a magnetic biasing structure having a first pinned layer, a second pinned layer, a spacer layer, and a free layer. The first pinned layer has a first magnetization pinned in the first direction. The second pinned layer has a second magnetization in a second direction that is substantially perpendicular or along the first direction. The spacer layer is nonferromagnetic, resides between the second pinned layer and the free layer, and is configured such that the free layer is substantially free of exchange coupling with the second pinned layer. The free layer has a shape anisotropy with a longitudinal direction substantially in the second direction. The magnetic biasing structure provides a bias field for the free layer along the hard or easy axis. In one aspect, the second pinned layer resides between the first pinned layer and the free layer.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: April 14, 2009
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Dmytro Apalkov
  • Publication number: 20090091865
    Abstract: A novel CCP scheme is disclosed for a CPP-GMR sensor in which an amorphous metal/alloy layer such as Hf is inserted between a lower Cu spacer and an oxidizable layer such as Al, Mg, or AlCu prior to performing a pre-ion treatment (PIT) and ion assisted oxidation (IAO) to transform the amorphous layer into a first metal oxide template and the oxidizable layer into a second metal oxide template both having Cu metal paths therein. The amorphous layer promotes smoothness and smaller grain size in the oxidizable layer to minimize variations in the metal paths and thereby improves dR/R, R, and dR uniformity by 50% or more. An amorphous Hf layer may be used without an oxidizable layer, or a thin Cu layer may be inserted in the CCP scheme to form a Hf/PIT/IAO or Hf/Cu/Al/PIT/IAO configuration. A double PIT/IAO process may be used as in Hf/PIT/IAO/Al/PIT/IAO or Hf/PIT/IAO/Hf/PIT/IAO schemes.
    Type: Application
    Filed: October 3, 2007
    Publication date: April 9, 2009
    Inventors: Kunliang Zhang, Min Li, Yue Liu, Hideaki Fukuzawa, Hiromi Yuasa
  • Patent number: 7515388
    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: April 7, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Mao-Min Chen, Chyu-Jiuh Torng, Min Li, Chen-Jung Chien
  • Publication number: 20090080125
    Abstract: A magnetic head is configured to include a free layer having a magnetization direction which is rotatable depending on an external field, a reference layer arranged parallel to the free layer and magnetically isolated from the free layer, and a pinned layer arranged parallel to the reference layer. The pinned layer and the reference layer are antiferromagnetically coupled. The pinned layer has a magnetization direction which is pinned in a predetermined direction, and a magnetization direction of the reference layer is antiparallel with respect to that of the pinned layer. The pinned layer is configured to have an area larger than that of the reference layer.
    Type: Application
    Filed: December 2, 2008
    Publication date: March 26, 2009
    Applicant: FUJITSU LIMITED
    Inventor: Reiko Kondo
  • Publication number: 20090080124
    Abstract: A magnetoresistive element includes: a first magnetization reference layer having magnetization perpendicular to a film plane, a direction of the magnetization being invariable in one direction; a magnetization free layer having magnetization perpendicular to the film plane, a direction of the magnetization being variable; a first intermediate layer provided between the first magnetization reference layer and the magnetization free layer; a magnetic phase transition layer provided on an opposite side of the magnetization free layer from the first intermediate layer, the magnetic phase transition layer being magnetically coupled to the magnetization free layer, and being capable of bidirectionally performing a magnetic phase transition between an antiferromagnetic material and a ferromagnetic material; and an excitation layer provided on an opposite side of the magnetic phase transition layer from the magnetization free layer, and causing the magnetic phase transition layer to perform the magnetic phase transi
    Type: Application
    Filed: September 15, 2008
    Publication date: March 26, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masatoshi Yoshikawa, Tadaomi Daibou, Eiji Kitagawa, Toshihiko Nagase, Tatsuya Kishi, Hiroaki Yoda
  • Patent number: 7506429
    Abstract: A magnetoresistive sensor having a well defined track width and method of manufacture thereof.
    Type: Grant
    Filed: February 7, 2005
    Date of Patent: March 24, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Howard Gordon Zolla, Edward Hin Pong Lee, Kim Y. Lee, Tsann Lin, Chun-Ming Wang
  • Patent number: 7505235
    Abstract: A method and apparatus for providing magnetostriction control in a synthetic free layer of a magnetic memory device is disclosed. A first free layer of CoFe alloy has a first thickness. A second free layer of NiFe alloy has a second thickness. At least one of the CoFe alloy and NiFe alloy includes at least one of B, P, Si, Nb, Zr, Hf, Ta and Ti. The relative thicknesses of the first and second free layer are modified to obtain a desired magnetostriction without a change in the magenetoristance ratio, ?R/R. The synthetic free layer may also be configured to have a net magnetic moment. A sensor may be a current-in-plane or a current-perpendicular-to-the-plane sensor. The sensor also may be configured to be a GMR sensor or a TMR sensor.
    Type: Grant
    Filed: May 21, 2007
    Date of Patent: March 17, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7505232
    Abstract: In a side shield structure employed to narrow the effective track, a noise caused by the side shield structure can be reduced. In one embodiment, the side shield is inclined with respect to the film plane to suppress the generation of a magnetic pole in the end portion of the side shield. To this end, the side face of a device is inclined at a desired angle. Further, a reproduction device is formed at two or more angles ?1 and ?2 to improve the track width accuracy.
    Type: Grant
    Filed: June 24, 2005
    Date of Patent: March 17, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Chiseki Haginoya, Masahiko Hatatani, Chiaki Ishakawa, Kenichi Meguro, Kazuhiro Nakamoto, Katsuro Watanabe
  • Patent number: 7500303
    Abstract: A read head for a disk drive and a method of fabricating the read head with overlaid lead pads that contact the top surface of the sensor between the hardbias structures to define the electrically active region of the sensor are described. The invention deposits the GMR and lead layers before milling away the unwanted material. A photoresist mask with a hole defining the active area of the sensor is preferably patterned over a layer of DLC that is formed into a mask. A selected portion of the exposed lead material is then removed using the DLC as a mask defining the active region of the sensor. A photoresist mask pad is patterned to define the full sensor width. The excess sensor and lead material exposed around the mask is milled away. The layers for the hardbias structure are deposited.
    Type: Grant
    Filed: May 19, 2006
    Date of Patent: March 10, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tsung Yuan Chen, Kuok San Ho, Mustafa Michael Pinarbasi
  • Patent number: 7502210
    Abstract: A magnetic detecting device having a large ?RA value is provided. A free magnetic layer has a three layer structure in which a CoFe layer, a NiaFeb alloy layer (here, a and b are represented by at %, and satisfy the relationship of 47?a?77 and a+b=100), and a CoFe layer are laminated. In addition, pinned magnetic layers have heusler alloy layers, which are made of a heusler alloy such as a Co2MnGe alloy. Accordingly, the product ?RA of a magnetic resistance variation ?R of the magnetic detecting device and an area A of the device can have a value of 5 m??m2 more.
    Type: Grant
    Filed: February 28, 2006
    Date of Patent: March 10, 2009
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yosuke Ide, Masamichi Saito, Masahiko Ishizone, Naoya Hasegawa
  • Patent number: 7502209
    Abstract: A read sensor of a magnetic head includes a sensor stack structure formed in a central region; hard bias layers formed in side regions adjacent the central region; and lead layers formed over the hard bias layers in the side regions. The hard bias layers are made of a nitrogenated cobalt-based alloy, such as nitrogentated cobalt-platinum-chromium (CoPtCr). Suitable if not exemplary coercivity and squareness properties are exhibited using the nitrogenated cobalt-based alloy. The hard bias layers are 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: October 24, 2005
    Date of Patent: March 10, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7499249
    Abstract: A magnetic detecting element capable of maintaining a large ?RA and reducing magnetostriction by changing a material of a free magnetic layer, and a method of manufacturing the same is provided. A CoMnXZ alloy layer or CoMnXRh alloy layer is formed in a free magnetic layer where an element X is at least one or two elements of Ge, Ga, In, Si, Pb, and Zn, and an element X in the latter case is at least one or two elements of Ge, Ga, In, Si, Pb, Zn, Sn, Al, and Sb. By forming the CoMnXZ alloy layer or the CoMnXRh alloy layer in the free magnetic layer, the magnetostriction of the free magnetic layer can be reduced while maintaining the large ?RA, compared with a case where only the CoMnX alloy is formed.
    Type: Grant
    Filed: April 24, 2006
    Date of Patent: March 3, 2009
    Assignee: TDK Corporation
    Inventors: Yosuke Ide, Masamichi Saito, Masahiko Ishizone, Naoya Hasegawa
  • Patent number: 7497008
    Abstract: An embodiment of the invention is a magnetic head with overlaid lead pads that contact the top surface of the sensor between the hardbias structures and do not contact the hardbias structures which are electrically insulated from direct contact with the sensor. The lead pad contact area on the top of the sensor is defined by sidewall deposition of a conductive material to form leads pads on a photoresist prior to formation of the remainder of the leads. The conductive material for the lead pads is deposited at a shallow angle to maximize the sidewall deposition on the photoresist, then ion-milled at a high angle to remove the conductive material from the field while leaving the sidewall material. An insulation layer is deposited on the lead material at a high angle, then milled at a shallow angle to remove insulation from the sidewall.
    Type: Grant
    Filed: August 24, 2005
    Date of Patent: March 3, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tsung Yuan Chen, Frederick Hayes Dill, James Mac Freitag, Kuok San Ho, Wipul Pemsiri Jayasekara, Kim Y. Lee, Mustafa Michael Pinarbasi, Ching Hwa Tsang, Patrick Rush Webb
  • Patent number: 7499248
    Abstract: A free magnetic layer is a laminated body of a Co2MnZ alloy layer (Z is one or more elements selected from a group consisting of Al, Sn, In, Sb, Ga, Si, Ge, Pb, and Zn) and a CoaFe100-a alloy layer. The CoaFe100-a alloy layer has a composition ratio 76?a?100 or a face-centered cubic (fcc) structure, in which an equivalent crystal face expressed as a {111} plane is preferentially oriented in a direction parallel to a film surface, and the CoaFe100-a alloy layer is in contact with the nonmagnetic material layer.
    Type: Grant
    Filed: March 10, 2006
    Date of Patent: March 3, 2009
    Assignee: TDK Corporation
    Inventors: Masahiko Ishizone, Masamichi Saito, Yosuke Ide, Naoya Hasegawa