Having Anisotropic Magnetoresistive (amr) Sensor Formed Of A Single Thin Film Patents (Class 360/327)
  • Patent number: 10276787
    Abstract: An integrated device includes a substrate having a semiconductor surface layer including functional circuitry, a lower metal stack on the semiconductor surface layer, an interlevel dielectric (ILD) layer on the lower metal stack, a top metal layer providing AMR contact pads and bond pads coupled to the AMR contact pads in the ILD layer. An AMR device is above the lower metal stack lateral to the functional circuitry including a patterned AMR stack including a seed layer, an AMR material layer, and a capping layer, wherein the seed layer is coupled to the AMR contact pads by a coupling structure. A protective overcoat (PO layer) is over the AMR stack. There are openings in the PO layer exposing the bond pads.
    Type: Grant
    Filed: February 11, 2016
    Date of Patent: April 30, 2019
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Dok Won Lee, William David French, Ricky Alan Jackson, Fuchao Wang
  • Patent number: 9508366
    Abstract: An apparatus disclosed herein includes a sensor with a free layer having cross-track easy axis anisotropy.
    Type: Grant
    Filed: August 23, 2013
    Date of Patent: November 29, 2016
    Assignee: SEAGATE TECHNOLOGY LLC
    Inventors: Victor Boris Sapozhnikov, Mohammed Sharia Ullah Patwari
  • Patent number: 9013838
    Abstract: Novel anisotropic magneto-resistive (AMR) sensor architectures and techniques for fabricating same are described. In at least one embodiment, an AMR sensor is provided that includes barber pole structures having upper and low metal layers that are formed of different materials. The metal material closer to the AMR element is formed of a material that can be etched using an etching process that does not attack the AMR material. In some other embodiments, AMR sensors having segmented AMR sensing elements are described.
    Type: Grant
    Filed: October 1, 2013
    Date of Patent: April 21, 2015
    Assignee: Allegro Microsystems, LLC
    Inventors: David G. Erie, Joseph Burkhardt, Steven Kosier
  • Patent number: 8963545
    Abstract: The present invention relates to a magnetic sensor that provides the sensitivity adjustment on a wafer and that has a superior mass productiveness and a small characteristic variation. The magnetic sensor includes a magnetic sensitive portion provided on a substrate that is made of a compound semiconductor and that has a cross-shaped pattern. This magnetic sensitive portion includes input terminals and output terminals. At least one of input terminals of the input terminal is series-connected to a trimming portion having a compound semiconductor via a connection electrode. By performing laser trimming on the trimming portion series-connected via the connection electrode to the magnetic sensitive portion while performing a wafer probing (electric test), the adjustment of the constant voltage sensitivity is provided.
    Type: Grant
    Filed: June 29, 2010
    Date of Patent: February 24, 2015
    Assignee: Asahi Kasei Microdevices Corporation
    Inventor: Satomi Watanabe
  • Patent number: 8885302
    Abstract: Novel anisotropic magneto-resistive (AMR) sensor architectures and techniques for fabricating same are described. In some embodiments, AMR sensors having barber pole structures disposed below corresponding AMR sensing elements are provided. AMR sensors having segmented AMR sensing elements are also described. Fabrication techniques that can be used to fabricate such sensors are also described. Fabrication techniques are also described that can reduce the risk of contamination during AMR sensor fabrication.
    Type: Grant
    Filed: October 1, 2013
    Date of Patent: November 11, 2014
    Assignee: Allegro Microsystems, LLC
    Inventors: Paul A. David, William P. Taylor, Bryan Cadugan
  • Patent number: 8848320
    Abstract: Novel anisotropic magneto-resistive (AMR) sensor architectures and techniques for fabricating same are described. In some embodiments, AMR sensors having barber pole structures disposed below corresponding AMR sensing elements are provided. AMR sensors having segmented AMR sensing elements are also described. Fabrication techniques that can be used to fabricate such sensors are also described. Fabrication techniques are also described that can reduce the risk of contamination during AMR sensor fabrication.
    Type: Grant
    Filed: October 1, 2013
    Date of Patent: September 30, 2014
    Assignee: Allegro Microsystems, LLC
    Inventors: Paul A. David, William P. Taylor, Bryan Cadugan
  • Patent number: 8829901
    Abstract: A method to measure a magnetic field is provided. The method includes applying an alternating drive current to a drive strap overlaying a magnetoresistive sensor to shift an operating point of the magnetoresistive sensor to a low noise region. An alternating magnetic drive field is generated in the magnetoresistive sensor by the alternating drive current. When the magnetic field to be measured is superimposed on the alternating magnetic drive field in the magnetoresistive sensor, the method further comprises extracting a second harmonic component of an output of the magnetoresistive sensor. The magnetic field to be measured is proportional to a signed amplitude of the extracted second harmonic component.
    Type: Grant
    Filed: November 4, 2011
    Date of Patent: September 9, 2014
    Assignee: Honeywell International Inc.
    Inventor: Bharat B. Pant
  • Patent number: 8400146
    Abstract: Provided is a stray field collector (SFC) pad and a bio-molecule sensing module or a biochip using the same, and more particularly, a SFC pad, in which probe or detection molecules are attached to a plurality of magnetic labels (magnetic particles or beads) and they are bonded to complementary molecules to enhance a stray field sensor signal of the magnetic labels remaining in the vicinity of the sensor, and a bio-molecule sensing module and a biochip using the same. The provided is related to qualitative as well as quantitative detection of magnetic labels, and the SFC pad which can increase an effective surface area sensitive to the magnetic labels by probe-detection molecular bond in a magnetic biosensor and collect the resultant stray field can enhance sensitivity, accuracy and resolution of the magnetic biosensor.
    Type: Grant
    Filed: February 3, 2010
    Date of Patent: March 19, 2013
    Assignee: The Industry & Academic Coorporation in Chungnam National University
    Inventors: Cheolgi Kim, Brajalal Sinha, Sunjong Oh, Jong-Ryul Jeong
  • Patent number: 8393073
    Abstract: A method for constructing a magnetoresistive sensor that avoids shadowing effects of a mask structure during sensor definition. The method includes the use of an antireflective coating (ARC) and a photosensitive mask deposited there over. The photosensitive mask is formed to cover a desired sensor area, leaving non-sensor areas exposed. A reactive ion etch is performed to transfer the pattern of the photosensitive mask onto the underlying ARC layer. The reactive ion etch (RIE) is performed with a relatively high amount of platen power. The higher platen power increases ion bombardment of the wafer, thereby increasing the physical (ie mechanical) component of material removal relative to the chemical component. This increase in the physical component of material removal result in an increased rate of removal of the photosensitive mask material relative to the ion mill resistant mask.
    Type: Grant
    Filed: July 21, 2008
    Date of Patent: March 12, 2013
    Assignee: HGST Netherlands B.V.
    Inventors: Richard Jule Contreras, Michael Feldbaum, Mustafa Michael Pinarbasi
  • Patent number: 8104166
    Abstract: A method is provided for fabricating a read element with leads that overlay a top surface of a sensor of the read element. The method includes forming a mask over a sensor layer, then using the mask to define the sensor from the sensor layer. The mask is then narrowed and a lead layer is formed that overlays both ends of the top surface of the sensor without covering a center portion of the top surface.
    Type: Grant
    Filed: December 19, 2003
    Date of Patent: January 31, 2012
    Assignee: Western Digital (Fremont), LLC
    Inventors: Jinqiu Zhang, Ming Zhao, Mohamad T. Krounbi, Henry Yuan, Lien-Chang Wang
  • Patent number: 8074345
    Abstract: A method of measuring a bevel angle in a write pole comprises the step of providing a mask over a wafer containing the write pole. The mask has a first opening over the write pole and a second opening over a sacrificial region of the wafer. The sacrificial region comprises a same material as the write pole. The method further comprises the steps of performing a beveling operation on the write pole and the sacrificial region to form a first bevel in the write pole and a second bevel in the sacrificial region, and measuring an angle of the second bevel in the sacrificial region to determine the bevel angle of the write pole.
    Type: Grant
    Filed: May 18, 2009
    Date of Patent: December 13, 2011
    Assignee: Western Digital (Fremont), LLC
    Inventors: Alexandre Anguelouch, Donghong Li
  • Patent number: 7596854
    Abstract: A method is disclosed for fabricating a read head for a magnetic disk drive having a read head sensor and a hard bias layer, where the read head has a shaped junction between the read head sensor and the hard bias layer. The method includes providing a layered wafer stack to be shaped. A single- or multi-layered photoresist mask having no undercut is deposited upon the layered wafer stack to be shaped. The layered wafer stack is shaped by the output of a milling source, where the shaping includes partial milling to within a partial milling range to form a shaped junction. A hard bias layer is then deposited which is in contact with the shaped junction of the wafer stack.
    Type: Grant
    Filed: September 4, 2007
    Date of Patent: October 6, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Marie-Claire Cyrille, Wipul Pemsiri Jayasckara, Mustafa Michael Pinarbasi
  • 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: 7450353
    Abstract: A magnetoresistive sensing apparatus is disclosed, comprising a magnetic film having a zig-zag shaped structure, a central axis, and a magnetization associated with the magnetic film, wherein the zig-zag shaped structure biases the magnetization direction alternately at positive and negative angles thereof, thereby permitting the magnetoresistive sensing apparatus to be sensitive to a magnetic field parallel to the axis of the magnetoresistive sensing apparatus and insensitive to magnetic fields perpendicular to the axis.
    Type: Grant
    Filed: October 6, 2005
    Date of Patent: November 11, 2008
    Assignee: The United States of America as represented by the Secretary of Commerce, The National Institute of Standards & Technology
    Inventors: David P. Pappas, Fabio da Silva, Jose Aumentado
  • Publication number: 20080218900
    Abstract: A multi-channel thin-film magnetic head has magnetic read head elements, magnetic write head elements, servo magnetic head elements, a plurality of pairs of external connection pads for reading connected with magnetic read head elements, a plurality of pairs of external connection pads for writing connected with magnetic write head elements, a plurality of pairs of external connection pads for servo connected with servo magnetic head elements, and a plurality of connection pads for body grounding or other functions. The connection pads for reading, writing, servo and body grounding or other functions are arranged in lines on a surface of the multi-channel thin-film magnetic head, and lead conductors which are electrically connected with connection pads for reading, writing, servo and body grounding or other functions are different each other in terms of widths, shapes, connection points or existence of a connector among at least two types of connection pads.
    Type: Application
    Filed: March 9, 2007
    Publication date: September 11, 2008
    Applicant: TDK CORPORATION
    Inventors: Nozomu Hachisuka, Tetsuya Hiraki
  • Publication number: 20080043381
    Abstract: In order to provide a magnetoresistive angle sensor (100) comprising a sensor device for detecting an angle (?) of an external magnetic field relative to a reference axis of the sensor device, which allows measurement of the angle (?) without the measurement result being affected by manufacturing errors, it is proposed that the sensor device comprises a flat AMR layer (14, 15) with one electrical contact (Ko) for applying a current (I) and a plurality of electrical contacts (Ki) for measuring a flow of current through the AMR layer (14,15).
    Type: Application
    Filed: December 20, 2004
    Publication date: February 21, 2008
    Applicant: KONINKLIJKE PHILIPS ELECTRONICS N.V.
    Inventor: Stefan Butzmann
  • Publication number: 20080037185
    Abstract: A magnetic memory is provided in which the margin between a write current and a read current can be reduced. A magnetic storage element includes: a first magnetic layer in which the direction of magnetization can be reversed; a second magnetic layer in which the direction of magnetization is fixed; and a non-magnetic layer which is interposed between the first and second magnetic layers. The write current and the read current are supplied to the magnetic storage element in the stacking direction thereof through a read-write line. Moreover, a bias line which can apply a bias magnetic field to the first magnetic layer during a reading operation is disposed in the vicinity of the magnetic storage element.
    Type: Application
    Filed: August 13, 2007
    Publication date: February 14, 2008
    Inventors: Katsumichi Tagami, Toshikazu Hosobuchi
  • Patent number: 7228618
    Abstract: A magnetic head having a spin valve sensor that is fabricated utilizing an Al2O3, NiMn0, Si seed layer upon which a PtMn spin valve sensor layer structure is subsequently fabricated. In the preferred embodiment, the Si layer has a thickness of approximately 20 ? and the PtMn layer has a thickness of approximately 120 ?. An alternative fabrication process of the Si 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 20 ?. The Si layer results in an improved crystal structure to the subsequently fabricated PtMn and other spin valve sensor layers, such that the fabricated spin valve is thinner and exhibits increased ?R/R and reduced coercivity.
    Type: Grant
    Filed: October 20, 2004
    Date of Patent: June 12, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: Mustafa Pinarbasi, Patrick Rush Webb
  • Patent number: 7199986
    Abstract: A magnetic sensor is provided, having two bias layers separated by a decoupling layer to eliminate exchange coupling between the bias layers. The two bias layers may have differing coercivities, such that the biases provided by the bias layers to the free layer are independently adjustable. The grain structures of the two bias layers may be substantially decorrelated by the decoupling layer.
    Type: Grant
    Filed: February 18, 2004
    Date of Patent: April 3, 2007
    Assignee: Hitachi Global Storage Technologies
    Inventors: Marie-Claire Cyrille, Meng Ding, Kuok-San Ho, Prakash Kasiraj, Ernesto Marinero, James Lamar Nix, Brian York
  • Patent number: 7194797
    Abstract: Methods for use in forming a CPP read sensor for a magnetic head are disclosed. In a particular example, a plurality of read sensor layers are formed over a first shield layer and a resist without undercuts is formed over the plurality of read sensor layers in a central region. With the resist in place, read sensor materials in side regions adjacent the central region are removed by milling to thereby form a read sensor structure in the central region. Insulator materials and metallic seed materials are then deposited in the side regions. High angle ion milling is performed to reduce a thickness of the insulator materials, the metallic seed materials, or both, along sidewalls of the read sensor structure. Magnetic hard bias materials are subsequently deposited over the metallic seed materials, and a second shield layer is formed over the structure after the resist is removed.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: March 27, 2007
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 7137192
    Abstract: A thin film head comprising a GMR element formed of an antiferromagnetic layer, a pinning layer, a nonmagnetic conductive layer and a free magnetic layer; and a pair of the right and the left laminated longitudinal biasing layers, each of the layers containing a hard magnetic layer, a nonmagnetic layer and a soft magnetic layer provided on said free magnetic layer of GMR element. Said hard magnetic layer and said soft magnetic layer are antiferromagnetically exchange-coupled via said nonmagnetic layer, and said hard magnetic layer and said free magnetic layer locating next to said hard magnetic layer are ferromagnetically coupled. The present invention contains also a method for manufacturing the thin film head.
    Type: Grant
    Filed: August 13, 2003
    Date of Patent: November 21, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaya Sakaguchi, Toshio Fukazawa
  • Patent number: 7103962
    Abstract: A magnetoresistive thin film head comprises a magnetoresistive element including an antiferromagnetic layer, a pinned layer, a nonmagnetic conductive layer and a free magnetic layer, and a pair of the right and the left laminated transverse biasing layers, each including a nonmagnetic layer, a ferromagnetic layer and an antiferromagnetic layer, provided on the free magnetic layer constituting said magnetoresistive element. The layer thickness of said nonmagnetic layer has been established to a certain specific value so that magnetizing direction in said free magnetic layer opposing to the ferromagnetic layer via said nonmagnetic layer assumes a direction that is opposite to that of said ferromagnetic layer.
    Type: Grant
    Filed: April 15, 2003
    Date of Patent: September 12, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaya Sakaguci, Toshio Fukazawa
  • Patent number: 7036208
    Abstract: A magnetoresistive sensor for use in a data storage device has a recessed sensing element (magnetic tunnel junction, CPP spin valve, etc.) with an exchange biased sensing ferromagnetic (free) layer, and a flux guide that magnetically connects the sensing element to a sensing surface of the sensor. The free layer is selectively exchange biased by a layer of exchange bias material placed under non-active regions of the free layer that lie outside the sensing element and flux guide track widths. The flux guide is provided by extending the free layer from a forward edge of the sensing element to the sensor surface. Advantageously, the sensing element and the flux guide have equal track width so that magnetic flux directed from the flux guide into the sensing element is not diluted with consequent loss of sensitivity.
    Type: Grant
    Filed: September 30, 2003
    Date of Patent: May 2, 2006
    Assignee: Hitachi Global StorageTechnologies Netherlands B.V
    Inventors: Kuok San Ho, Tao Pan
  • Patent number: 7020951
    Abstract: An antiferromagnetic stabilization scheme is employed in a magnetic head for magnetically stabilizing a free layer of a spin valve. This is accomplished by utilizing an antiferromagnetic oxide film below a spin valve sensor in a read region and first and second lead layers in end regions and a ferromagnetic film in each of the lead layers that exchange couples to the antiferromagnetic oxide film in the end regions. The ferromagnetic films are pinned with their magnetic moments oriented parallel to an air bearing surface (ABS) of the magnetic head. The ferromagnetic film magnetostatically couples to the free layer which causes the free layer to be in a single magnetic domain state. Accordingly, when the free layer is subjected to magnetic incursions from a rotating disk in a disk drive, the free layer maintains a stable magnetic condition so that resistance changes of the free layer are not altered by differing magnetic conditions of the free layer.
    Type: Grant
    Filed: November 7, 2003
    Date of Patent: April 4, 2006
    Assignee: International Business Machines
    Inventors: Tsann Lin, Daniele Mauri
  • Patent number: 6928723
    Abstract: An exchange-coupled magnetic structure of a cobalt-ferrite layer adjacent a magnetic metal layer is used in magnetorestive sensors, such as spin valves or tunnel junction valves. The exchange-coupled magnetic structure is used in a pinning structure pinning the magnetization of a ferromagnetic pinned layer, or in an AP pinned layer. A low coercivity ferrite may be used in an AP free layer. Cobalt-ferrite layers may be formed by co-sputtering of Co and Fe in an oxygen/argon gas mixture, or by sputtering of a CoFe2 composition target in an oxygen/argon gas mixture. Alternatively, the cobalt-ferrite layer may be formed by evaporation of Co and Fe from an alloy source or separate sources along with a flux of oxygen atoms from a RF oxygen atom beam source. Magnetoresistive sensors including cobalt-ferrite layers have small read gaps and produce large signals with high efficiency.
    Type: Grant
    Filed: December 23, 2003
    Date of Patent: August 16, 2005
    Assignee: International Business Machines Corporation
    Inventors: Matthew Joseph Carey, Hoa Van Do, Robin Frederick Charles Farrow, Bruce Alvin Gurney, David Thomas Margulies, Ronald Franklin Marks, Philip Milton Rice, Ren Xu
  • Patent number: 6910259
    Abstract: An antiferromagnetic stabilization scheme is employed in a magnetic head for magnetically stabilizing a free layer of a spin valve. This is accomplished by utilizing an antiferromagnetic oxide film below a spin valve sensor in a read region and first and second lead layers in end regions and a ferromagnetic film in each of the lead layers that exchange couples to the antiferromagnetic oxide film in the end regions. The ferromagnetic films are pinned with their magnetic moments oriented parallel to an air bearing surface (ABS) of the magnetic head. The ferromagnetic films magnetostatically couple to the free layer which causes the free layer to be in a single magnetic domain state. Accordingly, when the free layer is subjected to magnetic incursions from a rotating disk in a disk drive, the free layer maintains a stable magnetic condition so that resistance changes of the free layer are not altered by differing magnetic conditions of the free layer.
    Type: Grant
    Filed: November 24, 2000
    Date of Patent: June 28, 2005
    Assignee: International Business Machines Corporation
    Inventors: Tsann Lin, Daniele Mauri
  • Patent number: 6895658
    Abstract: A TMR element includes: a free layer formed on a lower gap layer; a tunnel barrier layer formed on the free layer; and a pinned layer formed on the tunnel barrier layer. The pinned layer and the tunnel barrier layer have sidewalls formed through etching. The TMR element further comprises a deposition layer made of a material that is separated by etching and deposits on the sidewalls and undergoes oxidation.
    Type: Grant
    Filed: April 30, 2003
    Date of Patent: May 24, 2005
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Satoru Araki
  • Publication number: 20040229082
    Abstract: Provided is a magnetoresistance device. The device includes a substrate, a lower layer formed on the substrate, and a magnetoresistance structure formed on the lower layer, and the lower layer is formed of amorphous ZrxAl1-x (0<x<1) or ZrxAl1-xOy (0<x<1, 0<y<1). In a tunneling magnetoresistance (TMR) device, a tunneling barrier layer is formed of at least one selected from the group consisting of ZrxAl1-xOy (0<x<1, 0<y<1), TixAl1-xOy (0<x<1, 0<y<1), and NbxAl1-xOy (0<x<1, 0<y<1).
    Type: Application
    Filed: January 29, 2004
    Publication date: November 18, 2004
    Applicant: KOREA CHUNGANG EDUCATIONAL FOUNDATION
    Inventors: Seong Rae Lee, Chul Min Choi, Jong Soo Kim, Jin Oh Song, Sung Min Park, Dong Hwan Kim
  • Patent number: 6817086
    Abstract: A bilayer mask employed for lift off has a top strip which bridges between first and second bilayer portions and is completely undercut so that when one or more materials is sputter deposited the materials do not form fences abutting recessed edges of a bottom layer in undercuts below a top layer. Sacrificial protective layers are formed on a sensor and lead layers for protecting these components while overlapping portions of these materials on the top of the sensor formed during deposition can be removed by ion beam sputtering, after which the sacrificial protective layers can be removed by ion milling or reactive ion etching.
    Type: Grant
    Filed: August 12, 2002
    Date of Patent: November 16, 2004
    Assignee: International Business Machines Corporation
    Inventors: Jennifer Qing Lu, Scott Arthur MacDonald, Hugo Alberto Emilio Santini
  • Patent number: 6802114
    Abstract: A method of making a dual spin valve sensor includes the steps of forming first and second pinned layer structures, forming antiferromagnetic first and second pinning layers exchange coupled to the first and second pinned layer structures, forming an antiparallel (AP) coupled free layer structure between the first and second pinned layer structures, forming nonmagnetic conductive first and second spacer layers between the AP coupled free layer structure and the first and second pinned layer structures respectively, and a making of the AP coupled free layer structure includes the steps of forming ferromagnetic first, second and third antiparallel (AP) coupled free layers and forming a first antiparallel coupling layer between the first and second AP coupled free layers and a second antiparallel coupling layer between the second and third AP coupled free layers.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: October 12, 2004
    Assignee: International Business Machines Corporation
    Inventor: Hardayal Singh Gill
  • Patent number: 6751844
    Abstract: A spin valve sensor has a pinned layer structure that has a net positive stress induced uniaxial anisotropy that promotes a pinning of the pinned layer structure in a pinned direction for stabilizing the pinning of the pinned layer structure at high temperatures near to a blocking temperature of a pinning layer which is exchange coupled to the pinned layer.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: June 22, 2004
    Assignee: International Business Machines Corporation
    Inventor: Mustafa Pinarbasi
  • Patent number: 6727694
    Abstract: Magnetoresistive sensors for angle measurements such as, for example, the sensors of the type KMZ 41, manufactured and marketed by Philips Semiconductors, utilize the effect that a sufficiently strong, external magnetic field H rotates the internal magnetization M in a parallel direction. In the case of said sensor KMZ 41, the magnetic field strength required for full alignment of the internal magnetization is 70 to 100 kA/m. A reduction of this high field strength is desirable and may be achieved by increasing the tendency of the internal magnetization to change its direction. An increase of the tendency of the internal magnetization to change its alignment is achieved in accordance with the invention by using a trigger structure and strip-shaped sensor elements of NiFe material which have elliptic contours or tapered ends. The trigger structure has a circular surface of NiFe material which is not electrically contacted. The internal magnetization of a circular surface may be rotated very easily, i.e.
    Type: Grant
    Filed: March 26, 2001
    Date of Patent: April 27, 2004
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Michael Doescher
  • Publication number: 20040061988
    Abstract: The present invention provides a method of manufacturing a thin film magnetic head realizing both high precision in formation of a main magnetic pole layer and proper position of a flare point and capable of contributing to an improvement in recording performance from a manufacturing viewpoint. By performing a series of patterning processes using a buffer layer and a non-magnetic layer of which etching rate is low as a stopper layer, a main magnetic pole layer is formed. First, at the time of forming a front end portion, a precursor main magnetic pole layer (preparation layer of the main magnetic pole layer) is patterned by using the buffer layer as a mask, so that the front end portion is formed with high precision to have a small width as designed.
    Type: Application
    Filed: September 30, 2003
    Publication date: April 1, 2004
    Applicants: TDK CORPORATION, SAE MAGNETICS (H.K.) LTD.
    Inventors: Naoto Matono, Norikazu Ota, Yuichi Watabe, Susumu Aoki, Yasuyuki Notsuke
  • Patent number: 6714389
    Abstract: A magnetoresistive sensor for sensing a magnetic storage medium includes a free layer that has a magnetic anisotropy that supports stable magnetic states. A magnetic field generator biases the stable states of the free layer. The magnetic field generator may permanently bias the free layer through the use of permanent magnets or may intermittently bias the free layer with a magnetic field generated by an alternating current. A magnetic storage medium is located proximate to the magnetoresistive sensor. The magnetoresistive sensor switches between stable magnetic states in response to the data on the magnetic storage medium. The magnetoresistive sensor senses the data stored in sectors on a magnetic medium by magnetically biasing the free layer, positioning the sensor proximate to a sector of the magnetic medium to be sensed, removing the magnetic bias and then sensing the magnetic state of the free layer while the magnetic bias is removed.
    Type: Grant
    Filed: October 30, 2001
    Date of Patent: March 30, 2004
    Assignee: Seagate Technology LLC
    Inventors: Taras Grigorievich Pokhil, Andrzej A. Stankiewicz, Janusz J. Nowak
  • Patent number: 6700761
    Abstract: A magnetic sensor for reproducing information recorded on a magnetic recording medium senses an external magnetic field using a spin-filtered sensor current flowing through a non-magnetic layer.
    Type: Grant
    Filed: March 6, 2001
    Date of Patent: March 2, 2004
    Assignee: Fujitsu Limited
    Inventors: Nobutaka Ihara, Hiroyoshi Kodama, Takuya Uzumaki
  • Patent number: 6662432
    Abstract: A free layer for a spin valve sensor includes a cobalt iron (CoFe) film which has an easy axis oriented perpendicular to an air bearing surface (ABS) of a read head and a nickel iron (NiFe) film which has an easy axis oriented parallel to the ABS and parallel to the major planes of the thin film layers. In a further embodiment the free layer is annealed at a high temperature in the presence of a field which is oriented perpendicular to the ABS.
    Type: Grant
    Filed: January 2, 2001
    Date of Patent: December 16, 2003
    Assignee: International Business Machines Corporation
    Inventors: Hamid Balamane, Dwight Cornwell, Jr., Hardayal Singh Gill, Serhat Metin, Mustafa Pinarbasi
  • Patent number: 6493194
    Abstract: A thin film magnetic head which includes a magnetoresistive layer selectively formed; a magnetic bias layer sandwiching said magnetoresistive layer; a pair of leads for detecting magnetic resistance; and a cap layer formed under the lead between the magnetoresistive layer. This configuration enables to accurately specify a magnetic response region by both ends of the cap layers, concentrating the current from the lead onto the magnetic response region through a tip of the cap layer for improving a S/N ratio.
    Type: Grant
    Filed: March 30, 2000
    Date of Patent: December 10, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Masaya Sakaguchi, Hiroyasu Tsuji, Satoru Mitani, Tadashi Kimura, Hiroyoshi Sekiguchi
  • Patent number: 6493193
    Abstract: In order to improve reliability of an MR head including a substrate, an MR element formed on the substrate, a reinforcing body, and a sliding surface with respect to a magnetic recording medium, in which the substrate and the MR element are exposed to the sliding surface, the substrate and the reinforcing body are bonded to each other by using a non-organic film, for example, a multi-layered film including metal layers. Alternatively, the substrate and the reinforcing body are bonded to each other via an adhesive film not exposed to the sliding surface.
    Type: Grant
    Filed: September 18, 2001
    Date of Patent: December 10, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yoshiyasu Honma, Hiroyuki Hasegawa
  • Patent number: 6434814
    Abstract: A method of making a magnetic head that has a read head with a track width includes the steps of depositing a read track width defining material layer on a read sensor material layer; forming a bi-layer photoresist mask on the read track width defining material layer that masks a read track width defining layer portion of the read track width defining material layer; removing by reactive ion etching (RIE) a portion of the read track width defining material layer not masked by the photoresist mask to form the read track width defining layer portion with exposed first and second side edges that are spaced apart a distance equal to the track width; removing by ion milling a first portion of the read sensor material layer not masked by the read track width defining layer portion to form a second portion of the read sensor material layer with exposed first and second side edges that have a width equal to the track width; depositing hard bias and lead material layers on the photoresist mask in contact with the firs
    Type: Grant
    Filed: December 16, 1998
    Date of Patent: August 20, 2002
    Assignee: International Business Machines Corporation
    Inventors: Henry C. Chang, Cherngye Hwang, Robert Otto Schwenker
  • Patent number: 6317302
    Abstract: A thin-film magnetic read head device comprises an end face extending in a first direction, in which a magnetic information carrier is movable with respect to the magnetic head device, and in a second direction, perpendicular to said first direction. The magnetic head device further comprises a multilayer structure with at least two soft-magnetic layers separated by a magnetic insulation layer and with at least one exchange biasing layer, which multilayer structure extends in the second direction and in a third direction, perpendicular to the first and the second direction, and forms at least one flux path in the first and the third direction. The exchange coupling between one of the soft-magnetic layers and the exchange biasing layer is at least partly reduced locally, i.e. interrupted or at least substantially reduced, in at least the second direction, while the exchange biasing layer extends uninterruptedly in the region of said reductions.
    Type: Grant
    Filed: August 2, 1999
    Date of Patent: November 13, 2001
    Assignee: U.S. Philips Corporation
    Inventors: Hans W. Van Kesteren, Derk J. Adelerhof, Reinder Coehoorn
  • Patent number: 6130810
    Abstract: A magnetic reluctance effect magnetic head in which a forward side electrode is stacked on at least the surface of a magnetic reluctance effect element facing a magnetic recording medium, and in which an upper magnetic pole is stacked on the forward side electrode for facing the magnetic reluctance effect element. A connecting length L1 between the magnetic reluctance effect element and the forward side electrode is shorter than a facing length L2 over which the upper magnetic pole and the magnetic reluctance effect element face each other via a magnetic gap G. The upper magnetic pole and the magnetic reluctance effect element have an area in which the upper magnetic pole and the magnetic reluctance effect element face each other over a distance g2 larger than a magnetic gap length g1 of the magnetic gap G. The upper magnetic pole may be formed to be progressively spaced apart from the magnetic reluctance effect element by being angled 30.degree.
    Type: Grant
    Filed: April 22, 1994
    Date of Patent: October 10, 2000
    Assignee: Sony Corporation
    Inventors: Takuji Shibata, Norio Saito, Yutaka Soda
  • Patent number: 6088204
    Abstract: A magnetoresistive sensor for use as the read sensor in magnetic recording disk drives uses a permalloy (approximate composition of Ni.sub.81,Fe.sub.19) sensor layer with a magnetoresistance coefficient significantly greater than prior art permalloy sensor layers for a range of permalloy film thicknesses. The permalloy film is deposited on a substrate, such as alumina, that is essentially non-reactive with permalloy at elevated temperatures while the substrate is heated. The permalloy films have a zero or slightly negative magnetostriction, low easy and hard axis coercivities, and a low anisotropy field. At very small film thicknesses the permalloy films formed with substrate heating exhibit an even greater percentage increase in magnetoresistance coefficient than at higher film thicknesses, thereby allowing the films to function in magnetic recording disk drive heads for use at very high linear recording densities.
    Type: Grant
    Filed: December 1, 1994
    Date of Patent: July 11, 2000
    Assignee: International Business Machines Corporation
    Inventors: Robin Frederick Charles Farrow, Ronald Franklin Marks, Daniele Mauri, Stuart Stephen Papworth Parkin