Having One Film Pinned (e.g., Spin Valve) Patents (Class 360/324.1)
  • Patent number: 6731477
    Abstract: Disclosed is a system and method for forming a current-perpendicular-to-plane (CPP) spin-valve sensor with one or more metallic oxide barrier layers in order to provide a low junction resistance and a high GMR coefficient. In disclosed embodiments, the metallic oxide barrier layers are formed with oxygen-doping/in-situ oxidation processes comprising depositing a metallic film in a first mixture of argon and oxygen gases and subsequent in-situ oxidization in a second mixture of argon and oxygen gases. The exposure to oxygen may be conducted at a low partial oxygen pressure and at a moderate temperature. Smaller, more sensitive CPP spin-valve sensors may be formed through the use of the oxygen-doping/in-situ oxidization processes of the present invention, thus allowing for greater densities of disk drive systems.
    Type: Grant
    Filed: September 20, 2001
    Date of Patent: May 4, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tsann Lin, Daniele Mauri
  • Patent number: 6731478
    Abstract: A slider includes an air-introducing plane, a groove, an air flow-out end, and a thin-film magnetic head formed on the air flow-out end. The thin-film magnetic head includes a magnetoresistive effect type film which includes a first ferromagnetic film having a direction of magnetization which is changeable, an antiferromagnetic film, a second ferromagnetic film having a direction of magnetization which is fixed, and a non-magnetic conductive film disposed between the first ferromagnetic film and the second ferromagnetic film. The thin-film magnetic head further includes a pair of magnetic domain control films respectively arranged at ends of the magnetoresistive effect type film, and a pair of electrodes directly overlapping both end domains of the magnetoresistive effect type film. A spacing between the electrodes is narrower than a spacing between the magnetic domain control films.
    Type: Grant
    Filed: March 28, 2003
    Date of Patent: May 4, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhiro Nakamoto, Yoshiaki Kawato
  • Publication number: 20040080854
    Abstract: A dual GMR or dual spin valve sensor has a self-pinned layer which has its magnetic moment pinned perpendicular to an air bearing surface by sense current fields from conductive layers in the dual spin valve sensor when a sense current is conducted therethrough. This scheme eliminates one of the antiferromagnetic pinning layers which is typically employed in a dual GMR or dual spin valve sensor. The self-pinned layer is thin so that its demagnetization field will not be greater than the sense current fields acting thereon. Because of the thinning of the self-pinned layer the spin valve effect of the spin valve sensor is degraded by scattering of conduction electrons at the boundary of the self-pinned layer.
    Type: Application
    Filed: June 30, 2003
    Publication date: April 29, 2004
    Applicant: Hitachi Global Storage Technologies
    Inventor: Hardayal Singh Gill
  • Publication number: 20040080874
    Abstract: The invention provides a magnetoresistive element in which the pinned magnetic layer includes at least one non-magnetic film and magnetic films sandwiching that non-magneticfilm, and the magnetic films are coupled with one another by magnetostatic coupling via the non-magnetic film. This element has an improved thermal resistance. Furthermore, the invention provides a magnetoresistive element in which the pinned magnetic layer is as described above. The magnetic films can be coupled with one another by magnetostatic coupling or antiferromagnetic coupling generating negative magnetic coupling. In this element, the magnetic field shift is reduced. Furthermore, the invention provides a magnetoresistive element in which at least one of the magnetic layers sandwiching the intermediate layer includes an oxide ferrite having a plane orientation with a (100), (110) or (111) plane. A magnetic field is introduced in a direction of the axis of easy magnetization in the plane.
    Type: Application
    Filed: October 16, 2003
    Publication date: April 29, 2004
    Applicant: MATSUSHITA ELECTRIC INDUSTRIAL CO., LTD.
    Inventors: Masayoshi Hiramoto, Hiroshi Sakakima, Hideaki Adachi, Nozomu Matukawa, Kenji Iijima, Mitsuo Satomi
  • Publication number: 20040080873
    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: Application
    Filed: February 5, 2003
    Publication date: April 29, 2004
    Inventors: Taku Shintani, Katsuro Watanabe, Masahiko Hatatani, Kikuo Kusukawa
  • Publication number: 20040080872
    Abstract: A magnetic sensor comprises magnetoresistive elements and permanent magnet films, which are combined together to form GMR elements formed on a quartz substrate having a square shape, wherein the permanent magnet films are paired and connected to both ends of the magnetoresistive elements, so that an X-axis magnetic sensor and a Y-axis magnetic sensor are realized by adequately arranging the GMR elements relative to the four sides of the quartz substrate. Herein, the magnetization direction of the pinned layer of the magnetoresistive element forms a prescribed angle of 45° relative to the longitudinal direction of the magnetoresistive element or relative to the magnetization direction of the permanent magnet film. Thus, it is possible to reliably suppress offset variations of bridge connections of the GMR elements even when an intense magnetic field is applied; and it is therefore possible to noticeably improve the resistant characteristics to an intense magnetic field.
    Type: Application
    Filed: October 16, 2003
    Publication date: April 29, 2004
    Inventors: Hideki Sato, Kokichi Aiso, Yukio Wakui
  • Patent number: 6728055
    Abstract: The present invention provides a method and apparatus for performing automated spin valve combined pinned layer reset and hard bias initialization at the head gimbal assembly level. The reset combines a current pulse with an assisting magnetic field. The pinned layer reset and hard bias initialization is automated and performed by a single tool at the head gimbal assembly level to increase manufacturing throughput.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: April 27, 2004
    Assignee: International Business Machines Corporation
    Inventors: Hardayal Singh Gill, Christopher Dana Keener, Gautam Ratilal Patel
  • Publication number: 20040075956
    Abstract: An improvement in the corrosion resistance of a magnetoresistive head is aimed for, and a high magnetoresistivity ratio is maintained. In a magnetoresistive head equipped with, as a magnetic sensor element for detecting magnetic signals while in contact with a magnetic recording medium, a spin-valve film, which has a structure where an anti-ferromagnetic layer, a pinned layer in which the direction of magnetization is pinned in a predetermined direction by an exchange-coupling magnetic field at work between itself and the anti-ferromagnetic layer, a free layer in which the direction of magnetization changes in accordance with an external magnetic field, and a non-magnetic layer for magnetically isolating the pinned layer and the free layer are layered, the corrosion potential of the spin-valve film relative to a standard hydrogen electrode measured while immersed in a NaCl solution of a concentration of 0.1 mol/L is specified at +0.4 [V vs. SHE] or above.
    Type: Application
    Filed: July 25, 2003
    Publication date: April 22, 2004
    Inventors: Hiroki Tetsukawa, Yutaka Soda, Akihiko Okabe
  • Patent number: 6724582
    Abstract: A current perpendicular to plane type magnetoresistive device has a magnetoresistive film, a pair of electrodes which allow a sense current to flow through the magnetoresistive film in a perpendicular direction to the plane thereof, and a biasing film which imparts a biasing magnetic field to the magnetoresistive film in a parallel direction to film plane. The direction of the magnetic field generated by the sense current flowing through the magnetoresistive film in the perpendicular direction to film plane is made substantially anti-parallel to the direction of the biasing magnetic field in a vicinity of a portion of the magnetoresistive film where a signal magnetic flux is introduced.
    Type: Grant
    Filed: January 18, 2002
    Date of Patent: April 20, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tomomi Funayama, Masayuki Takagishi, Masatoshi Yoshikawa, Kohichi Tateyama
  • Patent number: 6721142
    Abstract: A slider (34) for reading data from a disk surface (80), the slider (80) including a magneto-resistive head (36). The head (36) includes a transducer (58) having a stack of layers (59), each layer (62,66,70,74) having a proximal end (64,68,72,76) proximal to the disk surface, and a pair of electrical leads (82), connected to the transducer (58), each one of the electrical leads (82) also having a proximal end (83) proximal to the disk surface (80). At least one of the proximal ends (83) of the electrical leads (82) and the layers (66) is recessed to provide one or more recessed areas (92). The recessed areas (92) are then filled with protective material (94) to a depth such that when the layer of protective material (48) is worn from the proximal ends (64,68,72,76,83) by burnishing by the disk surface (80), protective material (94) still remains in the recessed areas (92).
    Type: Grant
    Filed: December 21, 2000
    Date of Patent: April 13, 2004
    Assignee: Western Digital (Fremont) Inc.
    Inventors: Dallas W. Meyer, Tien-Chih Lin, Michael A. Stacy
  • Patent number: 6721145
    Abstract: A method of initializing a magnetic sensor having two antiferromagnetic layers is described. The method takes advantage of the spin flop effect such that the two antiferromagnetic layers may be orthogonally initialized. The signal polarity of the sensor is well controlled.
    Type: Grant
    Filed: January 2, 2002
    Date of Patent: April 13, 2004
    Assignee: International Business Machines Corporation
    Inventor: Robert S. Beach
  • Patent number: 6721143
    Abstract: As the dimensions of spin valve heads continue to be reduced, a number of difficulties are being encountered. One such is with the longitudinal bias when an external magnetic field can cause reversal of the hard magnet, thereby causing a hysteric response by the head. This coercivity reduction becomes more severe as the hard magnet becomes thinner. This problem has been overcome by inserting a decoupling layer between the antiferromagnetic layer that is used to stabilize the pinned layer of the spin valve itself and the soft ferromagnetic layer that is used for longitudinal biasing. This soft ferromagnetic layer is pinned by a second antiferromagnetic layer deposited on it on its far side away from the first antiferromagnetic layer. The presence of the decoupling layer ensures that the magnetization of the soft layer is determined only by the second antiferromagnetic layer. The inclusion of the decoupling layer allows more latitude in etch depth control during manufacturing.
    Type: Grant
    Filed: August 22, 2001
    Date of Patent: April 13, 2004
    Assignee: Headway Technologies, Inc.
    Inventors: You Feng Zheng, Kochan Ju, Cheng T. Horng, Simon Liao, Ru Ying Tong
  • Patent number: 6716537
    Abstract: A magnetoresistive element includes a multilayered film comprising a magnetic detecting layer having a magnetoresistive effect, a pair of first antiferromagnetic layers in contact with the magnetic detecting layer of the multilayered film at a predetermined gap in the track width direction, the first antiferromagnetic layers aligning the magnetization direction of the magnetic detecting layer, and a pair of conductive layers in contact with the pair of first antiferromagnetic layers, the pair of conductive layers applying a detecting current to the multilayered film. The first antiferromagnetic layers are composed of an antiferromagnetic material having higher resistivity than that of the conductive layers. The conductive layers are superimposed with the corresponding first antiferromagnetic layers and are in contact with the magnetic detecting layer in a range of the predetermined gap.
    Type: Grant
    Filed: September 13, 2000
    Date of Patent: April 6, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventor: Yoshihiko Kakihara
  • Publication number: 20040061981
    Abstract: A system and method of reducing noise due to thermally activated spin waves in a magnetoresistive (MR) element is disclosed. The MR element includes a free layer, a reference layer, and a spacer layer, the spacer layer being positioned between the free layer and the reference layer. To reduce noise, a magnetization of the reference layer is pinned in a fixed direction. A spin polarized current perpendicular to a plane of the free layer, reference layer, and spacer layer is subsequently produced such that the current exerts a spin momentum transfer torque on localized electron spins to reduce noise due to thermally activated spin waves. The spin momentum transfer torque opposes the intrinsic damping of the free layer, thereby reducing noise in the MR element.
    Type: Application
    Filed: September 25, 2003
    Publication date: April 1, 2004
    Applicant: Seagate Technology LLC
    Inventor: Mark Covington
  • Publication number: 20040061982
    Abstract: The GMR read head includes a GMR read sensor and a longitudinal bias (LB) stack in a read region, and the GMR read sensor, the LB stack and a first conductor layer in two overlay regions. In its fabrication process, the GMR read sensor, the LB stack and the first conductor layer are sequentially deposited on a bottom gap layer. A monolayer photoresist is deposited, exposed and developed in order to open a read trench region for the definition of a read width, and RIE is then applied to remove the first conductor layer in the read trench region. After liftoff of the monolayer photoresist, bilayer photoresists are deposited, exposed and developed in order to mask the read and overlay regions, and a second conductor layer is deposited in two unmasked side regions. As a result, side reading is eliminated and a read width is sharply defined by RIE.
    Type: Application
    Filed: September 29, 2003
    Publication date: April 1, 2004
    Inventors: Tsann Lin, Daniele Mauri
  • Patent number: 6709767
    Abstract: Disclosed is a spin-valve sensor employing one or more in-situ oxidized films as cap and/or gap layers in order to achieve an increased GMR coefficient and improved thermal stability. A fabrication method comprises depositing multilayer metallic films on a wafer in ion-beam and DC-magnetron sputtering modules of a sputtering system, and then transferring the wafer in a vacuum to an oxidation module where in-situ oxidation is conducted. When the method is used to form a cap layer, the cap layer may only be partially oxidized. A magnetic-field annealing may be subsequently conducted without the substantial occurrence of interface mixing and oxygen diffusion during the anneal process. The resulting spin-valve sensor exhibits an increased GMR coefficient, possibly due to induced specular scattering of conduction electrons and improved thermal stability mainly due to the protection of an underlying sensing layer from interface mixing and oxygen diffusion during the annealing process.
    Type: Grant
    Filed: July 31, 2001
    Date of Patent: March 23, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tsann Lin, Daniele Mauri
  • Publication number: 20040052006
    Abstract: A magnetoresistance element, wherein a first electric conductor is so formed as to contact almost the center of the surface opposite to a non-magnetic layer of a first ferromagnetic layer so formed as to sandwich, along with a second ferromagnetic layer, the non-magnetic layer, and an insulator so formed as to cover at least the side surface of the first ferromagnetic layer and the non-magnetic layer is formed so as to cover the peripheral edge of the surface of the first ferromagnetic layer, whereby it is possible to prevent a leakage current from flowing from the first electric conductor to a second electric conductor along the side surfaces of the first ferromagnetic layer, the non-magnetic layer and the second ferromagnetic layer, and to make uniform a bias current running from the first electric conductor to the second electric conductor to thereby restrict variations in magnetoresistance characteristics such as MR value and junction resistance.
    Type: Application
    Filed: July 29, 2003
    Publication date: March 18, 2004
    Inventors: Akihiro Odagawa, Masayoshi Hiramoto, Nozomu Matsukawa, Masahiro Deguchi
  • Publication number: 20040047082
    Abstract: A method for forming an abutted junction GMR bottom spin valve sensor in which the free layer has a maximum effective length due to the elimination or minimization of bias layer and conducting lead layer overspreading onto the sensor element and the consequent reduction of current shunting. The overspreading is eliminated by forming a thin dielectric layer on the upper surface of the sensor element. When the biasing and conducting leads are formed on the abutted junction, they overspread onto this layer and the overspread can be removed by an ion-milling process during which the dielectric layer protects the sensor.
    Type: Application
    Filed: September 6, 2002
    Publication date: March 11, 2004
    Applicant: Headway Technologies, Inc.
    Inventors: Cherng-Chyi Han, Mao-Min Chen, Pokang Wang
  • Publication number: 20040042127
    Abstract: A magnetic head applies a current in a direction perpendicular to the film plane of a giant magnetoresistive multilayered film and includes a current-screen layer arranged very close to a free layer, which current-screen layer screens or reduces an area in which the current flows to one half to one hundredth. When the magnetic head further includes a domain control film on or in the vicinity of the giant magnetoresistive multilayered film, the resulting magnetic head has high output and high stability to thereby yield a magnetic recording and reading apparatus with a high recording density.
    Type: Application
    Filed: February 20, 2003
    Publication date: March 4, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Hiroyuki Hoshiya, Katsumi Hoshino, Yuko Tsuchiya
  • 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: 6700753
    Abstract: This invention presents a method and structure for magnetic spin valves. The spin valve structure includes a first ferromagnetic layer separated from a second ferromagnetic layer by a non-magnetic layer. The spin valve structure also includes a first specular scattering layer separated from a second specular scattering layer by the first ferromagnetic layer, the non-magnetic layer, and the second ferromagnetic layer. The first ferromagnetic layer can include a free layer and the non-magnetic layer can include a spacer layer. The second ferromagnetic layer can include a pinned layer or a reference layer. The specular scattering layers can include a material such as Y2O3, HfO2, MgO, Al2O3, NiO, Fe2O3, and Fe3O4. The specular scattering layers can also be used in a SAF structure. In the SAF structure, the antiferromagnetic coupling material can be co-deposited with the second specular scattering layer.
    Type: Grant
    Filed: April 12, 2001
    Date of Patent: March 2, 2004
    Assignee: Seagate Technology LLC
    Inventors: Eric W. Singleton, Kristin Joy Duxstad, Michael B. Hintz
  • Patent number: 6700720
    Abstract: A scheme for ultrafast magnetization reversal in an in-plane magnetized layer (3) is disclosed. For that, an external magnetic field {right arrow over (H)}ex is applied such that the magnetization {right arrow over (M)} precesses around the external magnetic field {right arrow over (H)}ex and the external magnetic field {right arrow over (H)}ex is maintained until the precession suffices to effect the magnetization reversal. The external magnetic field {right arrow over (H)}ex is applied approximately perpendicular to the magnetization {right arrow over (M)}.
    Type: Grant
    Filed: December 7, 2001
    Date of Patent: March 2, 2004
    Assignee: International Business Machines Corporation
    Inventors: Rolf Allenspach, Christian Horst Back, Hans-Christof Otto Siegmann
  • Patent number: 6700754
    Abstract: A spin valve sensor system and method for fabricating the same is provided. Included is a free layer and a pinned layer with a spacer layer disposed between the free layer and the pinned layer. Such spacer layer is oxidized for improving operational characteristics of the spin valve sensor.
    Type: Grant
    Filed: April 30, 2001
    Date of Patent: March 2, 2004
    Assignee: International Business Machines Corporation
    Inventors: Witold Kula, Alexander Zeltser
  • Publication number: 20040034991
    Abstract: A spin valve sensor is provided with a negative ferromagnetic coupling field −HFC for properly biasing a free layer and a spin filter layer is employed between the free layer and a capping layer for increasing the magnetoresistive coefficient dr/R of the spin valve sensor. A top portion of the free layer is oxidized for improving the negative ferromagnetic coupling field −HFC when the spin filter layer is employed for increasing the magnetoresistive coefficient dr/R.
    Type: Application
    Filed: June 30, 2003
    Publication date: February 26, 2004
    Applicant: Hitachi Global Storage Technologies
    Inventor: Mustafa Pinarbasi
  • Publication number: 20040027732
    Abstract: A magnetic read head for use in a magnetic data storage and retrieval system is disclosed. The read head is typically a giant magnetoresistive (GMR) spin valve read sensor with a portion of the GMR spin valve read sensor implanted with ions. The implanted ions improve the GMR sensor's sensitivity to changes in resistance by increasing the resistance of inefficient or ineffective portions of the sensor. The invention is also directed to methods of making GMR read sensors.
    Type: Application
    Filed: October 17, 2002
    Publication date: February 12, 2004
    Inventors: Brian Kelly, Kevin John Duddy, Alan Johnston, William O'Kane
  • Publication number: 20040027731
    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: Application
    Filed: May 6, 2003
    Publication date: February 12, 2004
    Inventors: Naoya Hasegawa, Eiji Umetsu
  • Publication number: 20040021991
    Abstract: This invention teaches a way for the shield to shield (S1-S2) distance of a magnetic read head to be reduced. The key feature is that the upper and lower dielectric layers D1 and D3, which are normally pure aluminum oxide, have each been replaced by a bilayer dielectric, which consists of aluminum oxide in contact with the shield layer followed by a layer of a high voltage breakdown material. For D1 this layer may be either tantalum oxide or tantalum nitride while for D3 our preferred material has been tantalum oxide. The addition of the two high breakdown layers allows the thickness of the upper and lower dielectric layers to be reduced without having to reduce the S2-S2 voltage difference.
    Type: Application
    Filed: July 8, 2003
    Publication date: February 5, 2004
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Publication number: 20040021990
    Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film including a magnetically pinned layer whose direction of magnetization is pinned substantially in one direction, a magnetically free layer whose direction of magnetization changes in response to an external magnetic field, and a nonmagnetic intermediate layer located between the pinned layer and the free layer; and a pair of electrodes electrically connected to said magnetoresistance effect film to supply a sense current perpendicularly to a film plane of said magnetoresistance effect film, The intermediate layer has a first layer including a first region whose resistance is relatively high and second regions whose resistance is relatively low. The sense current preferentially flows through the second regions when the current passes the first layer.
    Type: Application
    Filed: March 28, 2003
    Publication date: February 5, 2004
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Katsuhiko Koui, Masatoshi Yoshikawa, Masayuki Takagishi, Masashi Sahashi, Takeo Sakakubo, Hitoshi Iwasaki
  • Patent number: 6686068
    Abstract: A CPP magnetoresistive sensor with a spacer layer made of a heterogeneous material, which is composed of conductive grains within a highly resistive matrix, has a high resistance. The conductive grains are typically made of a conductive element or alloy that can operate as a GMR spacer material. The highly resistive matrix is typically made of a highly resistive or insulating element, alloy or compound that will hinder the flow of electrons. The sensing electrical current is passed through the conductive grains, which are typically made of the same material as GMR spacers, so the GMR is maintained even though the overall resistance is increased.
    Type: Grant
    Filed: February 21, 2001
    Date of Patent: February 3, 2004
    Assignee: International Business Machines Corporation
    Inventors: Matthew Joseph Carey, Jeffrey Robinson Childress, Bruce Alvin Gurney
  • Publication number: 20040012895
    Abstract: An enhanced giant magnetorestistive device, and a method of manufacturing the same. According to an exemplary embodiment, the enhanced giant magnetoresistive (GMR) device includes a plurality of layers of magnetic, non-magnetic conducting, and insulating materials. The exemplary construction includes a substrate over which is formed a seed layer. A buffer-oxide layer is formed over the seed layer. Formed over the buffer-oxide layer is a GMR stack having at least two layers. An exemplary GMR stack is formed as a three layer sandwich in which the two outside layers are fabricated from one or more ferromagnetic materials, and the inner layer or spacer layer is formed from one or more non-magnetic, conducting materials. In alternate embodiments, the GMR stack may take the form of various spin valves, and/or other various GMR stacks.
    Type: Application
    Filed: July 19, 2002
    Publication date: January 22, 2004
    Applicant: Honeywell International Inc.
    Inventors: Joel A. Drewes, William F. Witcraft
  • Publication number: 20040004791
    Abstract: A method and apparatus for providing precise control of magnetic coupling field in NiMn top spin valve heads and amplitude enhancement is disclosed. The magnetic coupling between free and pinned layers in NiMn top spin valve heads is precisely controlled by employing the surface oxidation of Cu seed layer or/and Cu spacer layer that improve both the interfacial quality and the crystalline texture. According to the present invention the magnitude of coupling field can be precisely controlled without affecting resistance, and the amplitude of giant magneto-resistive(GMR) heads is improved by 15% at the same coupling field without affecting asymmetry performance. Thus, the present invention improves not only the interfacial roughness, but also improves the magnetic layer texture. The oxidation of Cu seed layer in the NiMn top spin valve structure provides more robust process with good control in coupling field that affects asymmetry of a GMR head.
    Type: Application
    Filed: June 30, 2003
    Publication date: January 8, 2004
    Applicant: International Business Machines Corporation
    Inventor: Geon Choe
  • Patent number: 6669787
    Abstract: The invention relates to a method of manufacturing a spin valve structure (1) of the GMR-type. Such a structure includes a stack of a magnetic layer (11a 11b), a nonmagnetic layer (15) and a sense layer (17) of a ferromagnetic material. In order to obtain a spin valve structure having a very good GMR effect the method comprises the following specific steps: oxidation of the ferromagnetic material of the sense layer; deposition of aluminium on the oxidized ferromagnetic material; oxidation of the deposited aluminium using oxygen from the oxidized ferromagnetic material.
    Type: Grant
    Filed: June 12, 2001
    Date of Patent: December 30, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventors: Murray Fulton Gillies, Antonius Emilius Theodorus Kuiper
  • Publication number: 20030231436
    Abstract: A magnetic sensing element with improved magnetic detection output and a method for making the same are provided. In the magnetic sensing element, the length of an upper pinned magnetic layer an upper antiferromagnetic layer in a track width direction is larger than the length of a free magnetic layer in the track width direction. In making the magnetic sensing element, there is no need to remove side portions of the upper pinned magnetic layer and the upper antiferromagnetic layer. The materials of the upper pinned magnetic layer and the upper antiferromagnetic layer are thus prevented from redepositing on two side faces of the free magnetic layer during milling.
    Type: Application
    Filed: June 13, 2003
    Publication date: December 18, 2003
    Applicant: ALPS ELECTRIC CO., LTD.
    Inventor: Yoshihiro Nishiyama
  • Patent number: 6661622
    Abstract: A method for making spin valves with low and stable coupling field includes the oxygen exposure steps. In this method, a first ferromagnetic layer is deposited onto a substrate using an ion beam sputtering process. The first surface of the first ferromagnetic layer is exposed to an oxygen-rich atmosphere with oxygen partial pressure of about 5×10−6 Torr. Oxygen is physisorbed on the first surface. The oxygen partial pressure rapidly decreases before a spacer layer of about 20 Å thick copper is deposited onto the first oxygen treated surface. The spacer layer has a second surface, which is treated with oxygen with a process similar to the process for treating the first surface. The oxygen partial pressure rapidly decreases before the second ferromagnetic layer is deposited onto the second oxygen treated surface.
    Type: Grant
    Filed: July 17, 2000
    Date of Patent: December 9, 2003
    Assignee: International Business Machines Corporation
    Inventor: Mustafa Pinarbasi
  • Patent number: 6657828
    Abstract: Provided are a magnetic transducer having a higher rate of resistance change and a larger magnitude of resistance change and having better stability of properties, and a thin film magnetic head. A stack of an MR element has a stacked structure comprising an underlayer, an antiferromagnetic layer, a ferromagnetic layer, a first nonmagnetic layer, a first soft magnetic layer, a second soft magnetic layer, a second nonmagnetic layer and a high-resistance layer, which are stacked in sequence on the underlayer. The orientation of magnetization of the ferromagnetic layer is fixed by exchange coupling between the ferromagnetic layer and the antiferromagnetic layer. The orientations of magnetizations of the first soft magnetic layer and the second soft magnetic layer change according to an external magnetic field.
    Type: Grant
    Filed: February 1, 2001
    Date of Patent: December 2, 2003
    Assignee: TDK Corporation
    Inventors: Satoru Araki, Yoshihiro Tsuchiya, Masashi Sano, Takumi Uesugi
  • Publication number: 20030214761
    Abstract: A lead overlay magnetic sensor for use in a disk drive is provided having a protective cap layer disposed between the electrical leads and the sensor. The protective cap layer is preferably formed from ruthenium, rhodium, or other suitable material. The sensors thus formed have low resistance between the electrical leads and the sensor and also have well defined magnetic trackwidths.
    Type: Application
    Filed: May 16, 2002
    Publication date: November 20, 2003
    Inventors: James Mac Freitag, Mustafa Pinarbasi, Patrick Rush Webb
  • Patent number: 6650598
    Abstract: A magnetic head for reproducing a signal recorded on a recording medium, includes a substrate, a magnetic head core provided on the substrate, having a magnetic gap, and a magnetoresistance device provided on the magnetic head core. The magnetic head core is provided in such a manner that a thickness direction of the magnetic head core around the magnetic gap is substantially the same as a track width direction of the recording medium.
    Type: Grant
    Filed: November 12, 2002
    Date of Patent: November 18, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hiroshi Sakakima, Masahiro Birukawa, Kazuo Yokoyama, Masayoshi Hiramoto
  • Patent number: 6643915
    Abstract: A triple antiparallel (AP) coupled free layer structure is located between first and second pinned layer structures in a dual spin valve sensor. The triple AP coupled free layer structure includes first, second and third antiparallel (AP) coupled ferromagnetic free layers and nonmagnetic first and second antiparallel (AP) coupling layers. The first AP coupling layer is located between and interfaces the first and second AP coupled free layers and the second AP coupling layer is located between and interfaces the second and third AP coupled free layers. Magnetic moments of the first and third AP coupled free layers are parallel with respect to one another and, because of a strong antiparallel coupling, the second AP coupled free layer pins magnetic moments of the first and third AP coupled free layers antiparallel thereto.
    Type: Grant
    Filed: June 1, 2001
    Date of Patent: November 11, 2003
    Assignee: International Business Machines Corporation
    Inventor: Hardayal Singh Gill
  • Publication number: 20030206379
    Abstract: A current-perpendicular-to-plane (CPP) read head with an amorphous magnetic bottom shield layer and an amorphous nonmagnetic bottom lead gap layer is disclosed. The amorphous magnetic bottom shield layer and amorphous nonmagnetic bottom lead layer provide a planar surface for the CPP read head deposited thereon to exhibit a low ferromagnetic coupling field and a high giant (or tunneling) magnetoresistance coefficient. The amorphous magnetic bottom shield layer is preferably formed of an Fe-based or Co-based film. The amorphous nonmagnetic bottom lead layer is preferable formed of a W-based or Ni-based film.
    Type: Application
    Filed: February 4, 2002
    Publication date: November 6, 2003
    Inventors: Tsann Lin, Daniele Mauri
  • Patent number: 6643107
    Abstract: The invention provides a spin valve thin film element in which output characteristics and the stability of reproduced waveforms are improved, asymmetry is decreased, and the occurrence of side reading is prevented. The spin valve thin film element includes a lamination having an antiferromagnetic layer, a first pinned magnetic layer, a nonmagnetic intermediate layer, a second pinned magnetic layer, a nonmagnetic conductive layer, a free magnetic layer, and a backed layer composed of a nonmagnetic conductive material, which are laminated on a substrate. Hard bias layers are formed on both sides of the lamination, and orient the magnetization direction of the free magnetic layer in the direction crossing the magnetization direction of the second pinned magnetic layer. Electrode layers are formed on the hard bias layers to supply a sensing current J to the lamination. The electrode layers are formed to extend to the surface of the lamination toward the central portion from both sides of the lamination.
    Type: Grant
    Filed: October 4, 2000
    Date of Patent: November 4, 2003
    Assignee: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Kiyoshi Sato, Kenji Honda
  • Patent number: 6639765
    Abstract: A magnetoresistive element with an improved magnetoresistive effect achieved by interposing a titanium nitride layer between a substrate and a spinel-type magnetic substance is provided. The magnetoresistive element comprises a substrate and a multilayer film formed on the substrate, and the multilayer film includes a first magnetic layer, a nonmagnetic layer formed on the first magnetic layer and a second magnetic layer formed on this nonmagnetic layer. An electric current is supplied in a direction perpendicular to a film surface of the multilayer film, and a change in electrical resistance is detected by the electric current based on a change in a relative angle between a magnetization direction of the first magnetic layer and a magnetization direction of the second magnetic layer. The first magnetic layer has a spinel crystal structure, and the multilayer film further includes a titanium nitride layer interposed between the substrate and the first magnetic layer.
    Type: Grant
    Filed: September 25, 2001
    Date of Patent: October 28, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Hideaki Adachi, Masayoshi Hiramoto, Kenji Iijima, Hiroshi Sakakima
  • Publication number: 20030197983
    Abstract: A method for fabricating a longitudinally hard biased, bottom spin valve GMR sensor with a lead overlay (LOL) conducting lead configuration and a narrow effective trackwidth. The advantageous properties of the sensor are obtained by providing two novel barrier layers, one of which prevents oxidation of and Au diffusion into the free layer during annealing and etching and the other of which prevents oxidation of the capping layer during annealing so as to allow good electrical contact between the lead and the sensor stack.
    Type: Application
    Filed: April 17, 2002
    Publication date: October 23, 2003
    Applicant: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Mao-Min Chen, Chen-Jung Chien, Cherng-Chyi Han, Ru-Ying Tong, Chyu-Jiuh Torng, Hui-Chuan Wang
  • Patent number: 6636392
    Abstract: A thin-film magnetic head with an MR element, includes an MR film, under films each having a multilayer structure with a first under layer and a second under layer laminated on the first under layer, and magnetic domain control films joined to side end faces of the MR film through the under films.
    Type: Grant
    Filed: July 6, 2001
    Date of Patent: October 21, 2003
    Assignee: TDK Corporation
    Inventors: Noriyuki Ito, Koichi Terunuma, Fumihiro Hiromatsu
  • Publication number: 20030193759
    Abstract: A magnetoresistance effect device having a basic structure wherein a multi-layer film comprising a unit of magnetic layer/non-magnetic layer/magnetic layer/antiferromagnetic layer, or antiferromagnetic layer/magnetic layer/non-magnetic layer/magnetic layer is formed with a protective film on a surface of the magnetoresistance effect device employing one of a metal, oxide material, nitride material, a mixture of oxide and nitride material, a double-layer film of metal/oxide, a double-layer film of metal/nitride, or a double-layer film of metal/(mixture of oxide and nitride) of film thickness between 2 nm and 7 nm.
    Type: Application
    Filed: June 6, 2003
    Publication date: October 16, 2003
    Applicant: TDK CORPORATION
    Inventor: Kazuhiko Hayashi
  • Patent number: 6633465
    Abstract: A magnetoresistive element includes a first antiferromagnetic film, a first magnetic film having a magnetization direction fixed by magnetic coupling with the first antiferromagnetic film, a second antiferromagnetic film, a second magnetic film having a magnetization direction fixed by magnetic coupling with the second antiferromagnetic film, a third magnetic film having a magnetization direction able to rotate in response to an applied magnetic field, a first nonmagnetic film disposed between the first magnetic film and the third magnetic film, and a second nonmagnetic film disposed between the second magnetic film and the third magnetic film. The third magnetic film is disposed between the first nonmagnetic film and the second nonmagnetic film, the first magnetic film is disposed between the first antiferromagnetic film and the first nonmagnetic film, and the second magnetic film is disposed between the second antiferromagnetic film and the second nonmagnetic film.
    Type: Grant
    Filed: April 25, 2001
    Date of Patent: October 14, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Hoshiya, Katsuya Mitsuoka, Masaaki Sano, Reiko Arai, Susumu Soeya, Hiroshi Fukui, Moriaki Fuyama, Fumio Sato
  • Patent number: 6633464
    Abstract: A magnetoresistive (MR) device includes a synthetic antiferromagnetic (AFM) layer having an Fe/FeSi/Fe construction. A first Fe layer of the synthetic AFM layer has a magnetization substantially in a first direction, while a second Fe layer of the synthetic AFM layer has a magnetization substantially in a second direction that is substantially antiparallel to the first direction. The magnetoresistive device can be a spin valve in which a first surface of the synthetic AFM layer is adjacent to a pinning layer, and a second surface of the synthetic AFM layer is adjacent to a spacer layer. Further, the spin valve includes a free layer that overlies the spacer, thereby being separated from the synthetic AFM layer by the spacer. The pinning layer, synthetic AFM layer, spacer, and free layer can be bounded by a first shield and a second shield to provide magnetic shielding of the spin valve sensor.
    Type: Grant
    Filed: December 9, 1998
    Date of Patent: October 14, 2003
    Assignee: Read-Rite Corporation
    Inventors: Chih-Huang Lai, Zhupei Shi, Hua-Ching Tong, Robert E. Rottmayer, Charles W. Miller
  • Publication number: 20030189798
    Abstract: The GMR read head includes a GMR read sensor and a longitudinal bias (LB) stack in a read region, and the GMR read sensor, the LB stack and a first conductor layer in two overlay regions. In its fabrication process, the GMR read sensor, the LB stack and the first conductor layer are sequentially deposited on a bottom gap layer. A monolayer photoresist is deposited, exposed and developed in order to open a read trench region for the definition of a read width, and RIE is then applied to remove the first conductor layer in the read trench region. After liftoff of the monolayer photoresist, bilayer photoresists are deposited, exposed and developed in order to mask the read and overlay regions, and a second conductor layer is deposited in two unmasked side regions. As a result, side reading is eliminated and a read width is sharply defined by RE.
    Type: Application
    Filed: April 5, 2002
    Publication date: October 9, 2003
    Inventors: Tsann Lin, Daniele Mauri
  • Publication number: 20030184922
    Abstract: A magnetic disk apparatus has a magnetic recording medium including a recording layer formed on a nonmagnetic substrate, and a magnetic head including a magnetoresistive film arranged above the magnetic recording medium and a pair of electrodes formed on both surfaces of the magnetoresistive film along a track direction so as to make a sense current flow in a direction perpendicular to a plane of the magnetoresistive film. The recording layer has an easy axis of magnetization in a direction perpendicular to a track width direction, which is a direction of a magnetic field generated by the flow of the sense current, a ratio MA/Me of which recording layer is smaller than 0.6, where MA is a remanent magnetization in the track width direction and Me is a remanent magnetization in the direction of the easy axis of magnetization.
    Type: Application
    Filed: January 23, 2003
    Publication date: October 2, 2003
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Tomoko Taguchi
  • Publication number: 20030184924
    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: Application
    Filed: April 30, 2003
    Publication date: October 2, 2003
    Applicant: TDK Corporation
    Inventors: Koji Shimazawa, Satoru Araki
  • Publication number: 20030184923
    Abstract: A slider includes an air-introducing plane, a groove, an air flow-out end, and a thin-film magnetic head formed on the air flow-out end. The thin-film magnetic head includes a magnetoresistive effect type film which includes a first ferromagnetic film having a direction of magnetization which is changeable, an antiferromagnetic film, a second ferromagnetic film having a direction of magnetization which is fixed, and a non-magnetic conductive film disposed between the first ferromagnetic film and the second ferromagnetic film. The thin-film magnetic head further includes a pair of magnetic domain control films respectively arranged at ends of the magnetoresistive effect type film, and a pair of electrodes directly overlapping both end domains of the magnetoresistive effect type film. A spacing between the electrodes is narrower than a spacing between the magnetic domain control films.
    Type: Application
    Filed: March 28, 2003
    Publication date: October 2, 2003
    Inventors: Kazuhiro Nakamoto, Yoshiaki Kawato