Detail Of Sense Conductor Patents (Class 360/322)
  • Publication number: 20040257714
    Abstract: Provided is a magnetic head having a magnetoresistive device which has high output and is best suited to high-recording-density magnetic recording/reading. A magnetic sensor having large output can be realized by providing a magnetic sensor which comprises: a first ferromagnetic film; a conductor which intersects the first ferromagnetic film via a first intermediate layer; a current circuit structure which is connected so as to cause a current to flow from the first ferromagnetic layer to the conductor; a second ferromagnetic film which is formed on the conductor in an intersecting manner via a second intermediate layer and which generates a signal of voltage changing according to a change in an external magnetic field; a voltage change amplifier film which contains materials whose resistance changes nonlinearly due to voltage; and an electrode which is connected to the voltage change amplifier film.
    Type: Application
    Filed: May 20, 2004
    Publication date: December 23, 2004
    Applicant: Hitachi, Ltd.
    Inventors: Hiromasa Takahashi, Jun Hayakawa
  • Publication number: 20040257713
    Abstract: A lead overlay magnetoresistive sensor has leads with substantially vertical end walls to accentuate sense current near the ends of the leads. Insulating layers isolate the hard bias layers from the path of the sense current. A lead overlay magnetoresistive sensor does not exhibit significant trackwidth widening. A disk drive has a read element including a lead overlay magnetoresistive sensor with leads having substantially vertical end walls.
    Type: Application
    Filed: June 17, 2003
    Publication date: December 23, 2004
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 6833979
    Abstract: The present invention provides an improved current perpendicular to the plane thin film read head device and method of fabrication. With the present invention, the lower lead is formed to inhibit accumulation of redeposited lead material on CPP sensor element side walls during CPP sensor formation. In the preferred embodiment, the upper portion of the lower lead, which normally is etched during sensor element formation, is formed of a low sputter yield material to reduce redeposition flux to the sensor side walls. It is also preferred to form the upper portion of a material that also has a low value for the ratio of its sputter yield at the lead milling angle-to-its sputter yield at the side wall milling angle to inhibit redeposition accumulation on the side wall. It is preferred to clad conventional lead material with a low sputter yield ratio, low resistivity material, to inhibit side wall redeposition accumulation while also providing a low resistance lower lead.
    Type: Grant
    Filed: June 21, 2002
    Date of Patent: December 21, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Kenneth E. Knapp, Ronald A. Barr, Lien-Chang Wang, Benjamin P. Law, James Spallas
  • Publication number: 20040228042
    Abstract: An electrode layer for thin-film magnetic heads includes a Ta base sub-layer, an Au sub-layer functioning as a main conductive sub-layer, and a protective sub-layer, those sub-layers being disposed in that order. An Au electrode seed sub-layer containing any one of NiFeCr, NiCr, and NiFe is placed between the Ta base sub-layer and the Au sub-layer. The Au electrode seed sub-layer has a thickness of 40 to 100 Å.
    Type: Application
    Filed: May 10, 2004
    Publication date: November 18, 2004
    Applicant: Alps Electric Co., Ltd.
    Inventors: Masahiro Oshima, Naoya Hasegawa
  • Patent number: 6819530
    Abstract: A magnetic head assembly includes a first lead that is electrically connected to a CPP sensor for conducting a current through the sensor perpendicular to major planes of the layers of the sensor. A second lead extends from a stripe height of the sensor into the head assembly. A nonmagnetic electrically conductive bias layer, which has major planes that are parallel to the major planes of the sensor, is electrically connected to the sensor and the second lead so that when the current flows through the bias layer parallel to the major planes of the bias layer and perpendicular to a head surface of the CPP sensor a free layer of the sensor is biased by the bias layer.
    Type: Grant
    Filed: September 25, 2002
    Date of Patent: November 16, 2004
    Assignee: International Business Machines Corporation
    Inventor: Hardayal Singh Gill
  • Publication number: 20040223268
    Abstract: A first and a second longitudinal bias-applying films are formed via a first mask at both sides of a magnetoresistive effective element film so that the difference in surface level between the magnetoresistive effective element film and the first and the second longitudinal bias-applying films is set within ±20 nm. Then, a first and a second electrode films are formed so as to cover edge portions of the magnetoresistive effective element film and the first and the second longitudinal bias-applying films.
    Type: Application
    Filed: April 20, 2004
    Publication date: November 11, 2004
    Applicant: TDK Corporation
    Inventors: Noriyuki Ito, Kosuke Tanaka, Koichi Terunuma
  • Patent number: 6816345
    Abstract: Methods for reducing feature sizes of devices such as electromagnetic sensors are disclosed. A track width of a MR sensor is defined by a mask having an upper layer with a reduced width and a lower layer with a further reduced width. Instead of or in addition to being supported by the lower layer in the area defining the sensor, the upper layer is supported by the lower layer in areas that do not define the sensor width. In some embodiments the upper layer forms a bridge mask, supported at its ends by the lower layer, and the lower layer is completely removed over an area that will become a sensor. Also disclosed is a mask having more than two layers, with a bottom layer completely removed over the sensor area, and a middle layer undercut relative to a top layer.
    Type: Grant
    Filed: September 24, 2001
    Date of Patent: November 9, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Kenneth E. Knapp, Ronald A. Barr, Myron R. Cagan, Mark D. Thomas
  • Patent number: 6813121
    Abstract: A magnetic transducer (head) according to the invention includes multilayered electrically conductive leads from the magnetic sensor which include a thin tantalum seed layer followed by a thin chromium seed layer which is followed by a thicker rhodium layer. The dual seed layer of the invention significantly improves the conductivity of the rhodium. The Ta/Cr/Rh leads can be used with hard bias structures formed on a PtMn layer without having increased resistance.
    Type: Grant
    Filed: November 30, 2000
    Date of Patent: November 2, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventor: Mustafa Pinarbasi
  • Publication number: 20040201928
    Abstract: A magnetic head including a lead overlaid read head component in which the electrical current passing through the overlaid passive regions of the sensor layers is reduced. The parts of the electrical leads that overlay the sensor layers are comprised of gold. The exceptional electrical conductivity of gold allows most sensor electrical current to flow through the overlaid leads and significantly reduces the amount of sensor electrical current that passes through the overlaid sensor layers. The operational characteristics of the read head are improved because the overlaid passive regions of the sensor layers do not contribute to the sensor signal. Noise and side reading effects are thereby reduced. In alternative embodiments of the present invention of gold is also used to overlay portions of the electrical leads that are away from the overlaid portions. This further reduces the sensor electrical current that passes through the overlaid sensor layers.
    Type: Application
    Filed: April 10, 2003
    Publication date: October 14, 2004
    Inventor: Mustafa Pinarbasi
  • Patent number: 6798621
    Abstract: A magnetic head includes a tunnel valve sensor, a first shield coupled to a first end of the tunnel valve sensor, and a second shield coupled to a second end of the tunnel valve sensor. A first connecting column electrically couples the first shield to a first read pad, and a second connecting column electrically couples the second shield to a second read pad. However, the first connecting column is magnetically uncoupled from the first shield and the second connecting column is magnetically uncoupled from the second shield. Advantageously, this eliminates or substantially reduces the influence of the connecting columns (which may be made in part from the same magnetic materials as the pole pieces) on the magnetic properties of the shields. In one example, the first connecting column is offset from the first shield and is coupled to it through a first connecting neck, and similarly the second connecting column is offset from the second shield and is coupled to it through a second connecting neck.
    Type: Grant
    Filed: August 15, 2002
    Date of Patent: September 28, 2004
    Assignee: International Business Machines Corporation
    Inventors: Edward Hin Pong Lee, Jeffrey Gregory McCord
  • Patent number: 6798622
    Abstract: A method for forming a magnetoresistive (MR) sensor element. There is first provided a substrate. There is then formed over the substrate a seed layer. There is then formed contacting a pair of opposite ends of the seed layer a pair of patterned conductor lead layer structures. There is then etched, while employing an ion etch method, the seed layer and the pair of patterned conductor lead layer structures to form an ion etched seed layer and a pair of ion etched patterned conductor lead layer structures. Finally, there is then formed upon the ion etched seed layer and the pair of ion etched patterned conductor lead layers structures a magnetoresistive (MR) layered structure. Within the magnetoresistive (MR) sensor element, the pair of patterned conductor lead layer structures may be formed within a pair of recesses within an ion etch recessed dielectric isolation layer.
    Type: Grant
    Filed: February 19, 2003
    Date of Patent: September 28, 2004
    Assignee: Headway Technologies, Inc.
    Inventors: Kochan Ju, Jei-Wei Chang, Cheng Horng
  • Patent number: 6791804
    Abstract: A magnetoresistive-effect device includes a multilayer film, hard bias layers arranged on both sides of the multilayer film, and electrode layers respectively deposited on the hard bias layers. The electrode layers are formed, extending over the multilayer film. Under the influence of the hard bias layers arranged on both sides of the multilayer, the multilayer film, forming the magnetoresistive-effect device, has, on the end portions thereof, insensitive regions which exhibit no substantial magnetoresistive effect. The insensitive region merely increases a direct current resistance. By extending the electrode layers over the insensitive regions of the multilayer film, a sense current is effectively flown from the electrode layer into the multilayer film. With a junction area between the electrode layer and the multilayer film increased, the direct current resistance is reduced, while the reproduction characteristics of the device are thus improved.
    Type: Grant
    Filed: January 6, 2003
    Date of Patent: September 14, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Daigo Aoki, Naoya Hasegawa, Kenji Honda, Yoshihiko Kakihara
  • Publication number: 20040174640
    Abstract: In a narrow magnetoresistive head having a magnetic domain control film comprising a single layer of magnetic film or magnetic films antiferromagnetically coupled by means of a nonmagnetic member, it has been found that the magnetic domain can be controlled with a smaller magnetization film thickness product than anticipated so far and the range is defined relative to the geometrical track width in the present invention. By defining the magnetization film thickness product of the magnetic domain control film within a prescribed range of the invention, a magnetic head having higher output than usual and having stable output with no hysteresis in the transfer curve and with no output fluctuation can be attained.
    Type: Application
    Filed: February 24, 2004
    Publication date: September 9, 2004
    Applicant: Hitachi Global Storage Technologies Japan, Ltd.
    Inventors: Akira Morinaga, Chiaki Ishikawa, Norifumi Miyamoto
  • Patent number: 6783874
    Abstract: First electrode layers are formed on second antiferromagnetic layers, and in a step separate from the above, second electrode layers are formed above internal end surfaces of the second antiferromagnetic layers and the first electrode layers and parts of the upper surface of the multilayer film with an additional film provided therebetween. Since the first and the second electrode layers are formed separately, it is not necessary to perform mask alignment twice, and hence an overlap structure can be precisely formed in which the thickness of the second electrode layer at the left side is equivalent to that at the right side.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: August 31, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Eiji Umetsu, Naohiro Ishibashi, Masahiro Oshima
  • Patent number: 6779248
    Abstract: In bottom spin valves of the lead overlay type the longitudinal bias field that stabilizes the device tends to fall off well before the gap is reached. This problem has been overcome by providing a manufacturing process that includes inserting an additional antiferromagnetic layer between the hard bias plugs and the overlaid leads. This additional antiferromagnetic layer and the lead layer are etched in the same operation to define the read gap, eliminating the possibility of misalignment between them. The extra antiferromagnetic layer is also longitudinally biased so there is no falloff in bias strength before the edge of the gap is reached. A process for manufacturing the device is also described.
    Type: Grant
    Filed: March 7, 2002
    Date of Patent: August 24, 2004
    Assignee: Headway Technologies, Inc.
    Inventors: Moris M. Dovek, Tai Min
  • Publication number: 20040150920
    Abstract: A reproducing head of a thin-film magnetic head incorporates an MR element, a pair of bias field applying layers located to be adjacent to the side portions of the MR element, and a pair of electrode layers that are located on the bias field applying layers and overlap the MR element. The electrode layers each have a first layer that is laid over part of the top surface of the MR element via a protection layer, and a second layer that overlaps the first layer. In the method of manufacturing the reproducing head, after forming the protection layer on an element-to-be film to make the MR element, a first electrode-to-be film to make the first layers is formed continuously without interposing a step of exposing the protection layer to the air.
    Type: Application
    Filed: January 22, 2004
    Publication date: August 5, 2004
    Applicants: Headway Technologies, Inc, SAE Magnetics (H.K) Ltd.
    Inventors: Yoshitaka Sasaki, Takehiro Kamigama
  • Patent number: 6765767
    Abstract: A read head for use with magnetic recording media having a plurality of magnetic tracks includes a read sensor, first and second magnetic lead shields for improving track resolution, and first and second magnetic shields for improving linear resolution. The read sensor is formed on a side wall of one of the first and second magnetic lead shields using a technique such as ion beam deposition for enhanced film growth rate on the side wall. A magnetic disc drive storage system incorporating the read head and a method of making the read head are also included.
    Type: Grant
    Filed: November 15, 2001
    Date of Patent: July 20, 2004
    Assignee: Seagate Technology LLC
    Inventors: Isabel G. Trindade, Michael A. Seigler
  • Patent number: 6760966
    Abstract: As track density requirements for disk drives have grown more aggressive, GMR devices have been pushed to narrower track widths to match the track pitch of the drive width. Narrower track widths degrade stability, cause amplitude loss, due to the field originating from the hard bias structure, and side reading. This problem has been overcome in a process of manufacturing a device by adding an additional layer of soft magnetic material above the hard bias layers. The added layer provides flux closure to the hard bias layers thereby preventing flux leakage into the gap region. A non-magnetic layer must be included to prevent exchange coupling to the hard bias layers. In at least one embodiment the conductive leads are used to accomplish this.
    Type: Grant
    Filed: April 30, 2002
    Date of Patent: July 13, 2004
    Assignee: Headway Technologies, Inc.
    Inventors: Po Kang Wang, Moris Dovek, Jibin Geng, Tai Min
  • Publication number: 20040130834
    Abstract: A smaller electrode layer of an upper electrode is formed on a surface of a free magnetic layer. A domain controlling film of an insulating material is formed adjacent to the smaller electrode layer on the surface of the free magnetic layer. Magnetization of the free magnetic layer is oriented in a single direction based on magnetic exchange coupling between the domain controlling film and the free magnetic layer. An electric connection is established between the free magnetic layer and the upper electrode only through the smaller electrode layer. The path of a sensing current can be reduced in the free and a pinned magnetic layer. A higher sensitivity can thus be obtained in the CPP structure magnetoresistive element. Effective magnetic core width can also be reduced in the CPP structure magnetoresistive element.
    Type: Application
    Filed: July 22, 2003
    Publication date: July 8, 2004
    Applicant: FUJITSU LIMITED
    Inventors: Keiichi Nagasaka, Yutaka Shimizu
  • Publication number: 20040125513
    Abstract: A thin-film magnetic head comprises a magnetoresistive film, a pair of magnetic domain control layers for applying a bias magnetic field to the magnetoresistive film, a pair of electrode layers for supplying a current to the magnetoresistive film, first and second shield layers for shielding the magnetoresistive film, a first insulating layer disposed between the magnetoresistive film and magnetic domain control layer and the first shield layer, and a second insulating layer disposed between the magnetoresistive film and electrode layer and the second shield layer. The shield layers have a distance therebetween shorter at a position where the electrode layer and magnetic domain control layer are laminated than that at a position where the magnetoresistive film is located.
    Type: Application
    Filed: December 5, 2003
    Publication date: July 1, 2004
    Applicant: TDK CORPORATION
    Inventors: Kosuke Tanaka, Koji Shimazawa, Koichi Terunuma
  • Patent number: 6754055
    Abstract: A giant magneto-resistive effect element includes a laminated layer film having a ferromagnetic film, a non-magnetic film and an anti-ferromagnetic film. A current is caused to flow in the direction perpendicular to the film plane of the laminated layer film by upper and lower electrodes. Hard magnetic films are directly connected to both sides in the width direction of the laminated layer film. Insulating films are formed above or under the hard magnetic films. A current path between the upper electrodes or the lower electrodes and the laminated layer film is restricted by an opening defined between the insulating layers at both sides. The hard magnetic films have a specific resistance substantially the same as or larger than that of the laminated layer film. Further, there are provided a magneto-resistive effect type head, a thin-film magnetic memory and a thin-film magnetic sensor including the above-mentioned giant magneto-resistive effect element.
    Type: Grant
    Filed: March 7, 2002
    Date of Patent: June 22, 2004
    Assignee: Sony Corporation
    Inventors: Hiroaki Ono, Atsushi Matsuzono, Shoji Terada, Shigehisa Ohkawara, Eiji Makino
  • Patent number: 6754052
    Abstract: A magnetoresistive head including a first magnetic shield, a first electrode terminal provided on the first magnetic shield and having a first width, and a magnetoresistive film provided on the first electrode terminal and having a second width less than or equal to the first width. The magnetoresistive head further includes a second electrode terminal provided on the magnetoresistive film and having a third width less than or equal to the second width, and a second magnetic shield provided on the second electrode terminal. Preferably, the magnetoresistive head further includes a plug electrode for connecting the second electrode terminal to the second magnetic shield, and a plug side wall protective insulating film for covering a side wall of the plug electrode.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: June 22, 2004
    Assignee: Fujitsu Limited
    Inventors: Hiroshi Asida, Shin Eguchi, Atsushi Tanaka, Reiko Kondo, Yutaka Shimizu
  • Publication number: 20040114282
    Abstract: A self aligned magnetoresistive sensor having a narrow and well defined track width and method of manufacture thereof.
    Type: Application
    Filed: December 17, 2002
    Publication date: June 17, 2004
    Applicant: International Business Machines Corporation
    Inventors: Edward Hin Pong Lee, Kim Y. Lee, Tsann Lin
  • Publication number: 20040109263
    Abstract: A manufacturing method of a magnetic head includes a process for forming a lift-off mask pattern on a magnetoresistance effect element, such that the upper part of the lift-off mask pattern is larger in size than the lower part, a process for forming a couple of electrodes on the magnetoresistance effect element using the lift-off mask pattern as a mask, and a process for removing the lift-off mask pattern. The process for forming the lift-off mask pattern is performed according to a dry etching process.
    Type: Application
    Filed: March 27, 2003
    Publication date: June 10, 2004
    Inventors: Shoichi Suda, Masayuki Takeda, Keiji Watanabe
  • Publication number: 20040105196
    Abstract: A magnetoresistive film 4, hard magnetic layers 22a and 22b disposed from both ends thereof for stabilizing the magnetoresistive film 4 and main electrode layers 24a, 24b for applying a current for sensing are disposed, the width of the pinning layer 12 is made narrower relative to the width of the free layer 14 in the magnetoresistive film 4 and overlaid electrode layers 21a, 21b are respectively disposed between the main electrode layer 24a and one end of the pinning layer 12 and between the main electrode layer 24b and the other end of the pinning layer 12. Thus, the respective low sensitivity regions near the contact portions respectively located between the hard magnetic layer 22a and one end of the magnetoresistive film 4 and between the hard magnetic layer 22b and the other end of the magnetoresistive film 4 are made into insensitive regions.
    Type: Application
    Filed: September 17, 2003
    Publication date: June 3, 2004
    Applicant: Hitachi Global Storage Technologies Japan, Ltd.
    Inventor: Kouji Kataoka
  • Patent number: 6744607
    Abstract: A spin valve sensor includes an antiparallel (AP) pinned layer structure which is self-pinned without the assistance of an antiferromagnetic (AFM) pinning layer. A free layer of the spin valve sensor has first and second wing portions which extend laterally beyond a track width of the spin valve sensor and are exchange coupled to first and second AFM pinning layers. Magnetic moments of the wing portions of the free layer are pinned parallel to the ABS and parallel to major planes of the layers of the sensor for magnetically stabilizing the central portion of the free layer which is located within the track width. The spin valve sensor has a central portion that extends between the first and second AFM layers. First and second lead layers overlay the first and second AFM layers and further overlay first and second portions of the central portion so that a distance between the first and second lead layers defines a track width that is less than a distance between the first and second AFM layers.
    Type: Grant
    Filed: March 21, 2002
    Date of Patent: June 1, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Pinarbasi, Patrick Rush Webb
  • Publication number: 20040100738
    Abstract: In a lead overlay (LOL) type of read head first and second insulation layers are employed with the first insulation layer being located between a top surface of a first hard bias layer and a first lead layer and the second insulation layer is located between the top surface of a second hard bias layer and a second lead layer for minimizing a shunting of a sense current through the hard bias layers into a read sensor.
    Type: Application
    Filed: November 22, 2002
    Publication date: May 27, 2004
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Ashok Lahiri, Mustafa Pinarbasi
  • Patent number: 6735058
    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: Grant
    Filed: February 4, 2002
    Date of Patent: May 11, 2004
    Assignee: International Business Machines Corporation
    Inventors: Tsann Lin, Daniele Mauri
  • Patent number: 6735059
    Abstract: A magnetoresistive effective type element, comprising: a magnetoresistive effective film; a first shielding film of which one main surface is adjacent to one main surface of said magnetoresistive effective film; a second shielding film of which one main surface is adjacent to the other main surface of said magnetoresistive effective film; and a third shielding film of which one main surface is adjacent to the other main surface of said first shielding film or said second shielding film opposite to said magnetoresistive effective film, wherein said first shielding film and said second shielding film function as current-supplying layers to flow current perpendicular to and through said magnetoresistive effective film, and wherein said first shielding film and said second shielding film are made of at least one selected from the group consisting of NiFe, CoZrTa, FeN, FeAlSi, NiFe alloy, Co-based amorphous material and Fe-based soft magnetic material.
    Type: Grant
    Filed: April 10, 2002
    Date of Patent: May 11, 2004
    Assignee: TDK Corporation
    Inventor: Junichi Sato
  • 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
  • Patent number: 6731475
    Abstract: A current-perpendicular-to-the-plane (CPP) structure electromagnetic transducer element comprises upper and lower electrically-conductive lead layers. The lead layers are employed to supply an electric current to an electromagnetic transducer film. An electrically-conductive terminal piece is allowed to stand on the surface of the lower electrically-conductive lead layer. The contact established between the electrically-conductive terminal piece and the electromagnetic transducer film is allowed to define the path for the electric current. The reduced contact area of the electrically-conductive terminal piece contributes to reduction in the size or extent of the path for the electric current through the electromagnetic transducer film. The path of the electric current can be reduced in the CPP structure electromagnetic transducer element without relying on reduction in the size of the electromagnetic transducer film.
    Type: Grant
    Filed: September 12, 2001
    Date of Patent: May 4, 2004
    Assignee: Fujitsu Limited
    Inventor: Junya Ikeda
  • Publication number: 20040075954
    Abstract: The present invention is directed towards increasing the conductivity of the electrical lead material in the read head portion of a magnetic head, such that thinner electrical leads can be fabricated while the current carrying capacity of the leads is maintained. This increase in electrical lead conductivity is accomplished by fabricating the electrical lead upon an epitaxially matched seed layer, such that the crystalline microstructure of the electrical lead material has fewer grain boundaries, whereby the electrical conductivity of the lead material is increased. In a preferred embodiment, the electrical lead material is comprised of Rh, which has an FCC crystal structure, and the seed layer is comprised of a metal, or metal alloy having a BCC crystal structure with unit cell lattice constant dimensions that satisfy the relationship that abcc is approximately equal to 0.816afcc. In various embodiments, the seed layer is comprised of VMo or VW.
    Type: Application
    Filed: October 17, 2002
    Publication date: April 22, 2004
    Inventors: Michael Andrew Parker, Mustafa Pinarbasi, Robert Otto Schwenker
  • Patent number: 6718623
    Abstract: A reproducing head of a thin-film magnetic head incorporates an MR element, a pair of bias field applying layers located to be adjacent to the side portions of the MR element, and a pair of electrode layers that are located on the bias field applying layers and overlap the MR element. The electrode layers each have a first layer that is laid over part of the top surface of the MR element via a protection layer, and a second layer that overlaps the first layer. In the method of manufacturing the reproducing head, after forming the protection layer on an element-to-be film to make the MR element, a first electrode-to-be film to make the first layers is formed continuously without interposing a step of exposing the protection layer to the air.
    Type: Grant
    Filed: May 17, 2002
    Date of Patent: April 13, 2004
    Assignees: Headway Technologies, Inc., SAE Magnetics (H.K.)
    Inventors: Yoshitaka Sasaki, Takehiro Kamigama
  • 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: 6714374
    Abstract: A magnetoresistive sensor includes a magnetoresistive element and equipment which generates a magnetic field in the magnetoresistive element thereby inducing a biasing magnetic field in the element, where the magnetoresistive element comprises a high electron mobility semiconductor and electrodes which are connected to the semiconductor. If it is an insulator, the equipment, which generates the biasing magnetic field and supplies it to the magnetoresistive element, may contact directly to the magnetoresistive element. If it is a conductor, an insulating separation layer must be set between the equipment and the element. A magnetoresistive element is representatively Corbino disk type or a bar type magnetoresistive element. Another candidate of the magnetoresistive element is an element consisting of a high electron mobility semiconductor, a pair of electrodes which make a current path in the high electron mobility semiconductor, and another pair of electrodes to detect the induced voltage by the current.
    Type: Grant
    Filed: August 31, 2000
    Date of Patent: March 30, 2004
    Assignee: NEC Corporation
    Inventors: Kazuhiko Hayashi, Keishi Ohashi, Stuart Solin, Tao Zhou
  • Publication number: 20040057163
    Abstract: A read head, which has a head surface facing a moving magnetic medium, includes a read sensor that has first and second side top surface portions and a central top surface portion located between the first and second side top surface portions. First and second overlaying lead layers interface the first and second side top surface portions. First and second hard bias and tapered lead layers interface the first and second overlaying lead layers. A central top surface portion of the read sensor has a width that defines a track width of the read sensor. A method of making the read head includes ion-milling a partially oxidized portion of a cap layer and, after depositing the aforementioned first and second hard bias and tapered lead layers, preferentially reactive ion etching (RIE) the overlaying lead layer not covered by the first and second hard bias and tapered lead layers, so as to define the central top surface portion of the read sensor.
    Type: Application
    Filed: September 25, 2002
    Publication date: March 25, 2004
    Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Tsann Lin
  • Publication number: 20040052005
    Abstract: A magnetoresistive sensor having a well defined track width and method of manufacture thereof.
    Type: Application
    Filed: September 12, 2002
    Publication date: March 18, 2004
    Applicant: International Business Machines Corporation
    Inventors: Howard Gordon Zolla, Edward Hin Pong Lee, Kim Y. Lee, Tsann Lin, Chun-Ming Wang
  • Patent number: 6707648
    Abstract: A magnetic element having an improved MR rate. The magnetic element 1 is made up of plural layered films of different compositions and exhibits a magneto-resistance effect that the magneto-resistance value is changed on application of a magnetic field. The magnetic element 1 includes a recess 11 for transmitting the current along the layering direction of the layered films. The current flows through the portion of the magnetic element 1 not having the recess 11 so as to have a component along the film layering direction A, with the result that electrons taking part in current conduction may be propagated as the electrons traverse the boundary surfaces of the plural layered films.
    Type: Grant
    Filed: May 18, 2001
    Date of Patent: March 16, 2004
    Assignee: Nih n University
    Inventors: Akiyoshi Itoh, Katsuji Nakagawa
  • Publication number: 20040047081
    Abstract: A method for forming a thin conductive lead layer of high sheet conductivity, high hardness, high melting point, high corrosion resistance and lacking the propensity for smearing, oozing, electromigration and nodule formation. Said lead layer is formed upon the hard magnetic longitudinal bias layer of an abutted junction spin-valve type magnetoresistive read head and said read head is therefore suitable for reading high density recorded disks at high RPM.
    Type: Application
    Filed: August 27, 2003
    Publication date: March 11, 2004
    Applicant: HEADWAY TECHNOLOGIES, INC.
    Inventors: Cheng T. Horng, Mao-Min Chen, Chen-Jung Chien, Cherng-Chyi Han, Chyu-Jiuh Torng, Ru-Ying Tong
  • Patent number: 6704178
    Abstract: A multichannel magnetic head utilizing the magnetoresistive effect comprises a plurality of magnetoresistive effect type reproducing magnetic head elements arrayed between a first and second magnetic shield and electrodes wherein the reproducing magnetic head elements are arrayed in parallel on at least the first magnetic shield and electrode. Electrodes on one side are constructed commonly by the first magnetic shield and led out as a single common terminal decreasing the number of terminals.
    Type: Grant
    Filed: March 7, 2002
    Date of Patent: March 9, 2004
    Assignee: Sony Corporation
    Inventors: Eiji Nakashio, Seiji Onoe, Junichi Sugawara
  • 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
  • Publication number: 20040037014
    Abstract: In fabricating the magnetic head, a first magnetic shield layer (S1) is fabricated upon a substrate base, followed by a thin first insulation layer (G1). A photoresist mask is fabricated upon the G1 layer and electrical lead recesses are milled through the G1 layer and into the S1 layer. An insulation layer is deposited into the electrical lead recesses, followed by the fabrication of electrical leads within the recesses. The photoresist is removed and a magnetoresistive (MR) sensor is subsequently fabricated on top of the G1 layer, such that portions of the MR sensor are fabricated on top of portions of the electrical leads. Hard bias elements are then fabricated at outboard edges of the MR sensor. A thin second insulation layer (G2) is fabricated on top of the MR sensor and hard bias elements, and a second magnetic shield layer (S2) is fabricated on top of the G2 layer.
    Type: Application
    Filed: August 26, 2002
    Publication date: February 26, 2004
    Inventors: Daniele Mauri, Tao Pan
  • Publication number: 20040027730
    Abstract: A narrow track width read sensor having a high magnetoresistive sensitivity is made using a self-aligned process which requires the use of only a single resist mask. A plurality of sensor layers which includes a top layer of noble metal is deposited over a substrate. Optionally, a central protective barrier which is conductive or reactive-ion-etchable is formed over these sensor layers. After forming a resist mask in the central region, first lead layers are deposited in the end regions and over the resist mask. Using the resist mask, ion milling is performed such that the first lead layers and sensor layers in the end regions are substantially removed but sensor layers in the central region remain, to thereby form a read sensor having lead overlays on the edges thereof. Hard bias and second lead layers are then deposited in the end regions and over the resist mask.
    Type: Application
    Filed: August 9, 2002
    Publication date: February 12, 2004
    Inventor: Jeffrey Scott Lille
  • 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
  • Patent number: 6690552
    Abstract: There is provided a magnetoresistive film high in resistance to destruction. The magnetoresistive film is a multilayered film including: an antiferromagnetic layer 2 for generating a bias magnetic field; a pinned magnetic layer 3 having magnetization whose direction is fixed by the bias magnetic field; a free magnetic layer 5 having magnetization whose direction changes in accordance with an external magnetic field; and a nonmagnetic middle layer 4 held between the pinned magnetic layer and the free magnetic layer, and is held by a pair of insulation layers (not shown). When a current is passed parallel to the magnetoresistive film, a current center as a position of the thickness direction for dividing the current into two so as to obtain respective equal current amounts is positioned on a side including the pinned magnetic layer during dividing of the magnetoresistive film into two in a center position of a layer thickness of the nonmagnetic middle layer in the thickness direction.
    Type: Grant
    Filed: December 4, 2000
    Date of Patent: February 10, 2004
    Assignee: Fujitsu Limited
    Inventors: Kenji Noma, Hitoshi Kanai
  • Patent number: 6671133
    Abstract: It is an object of a thin-film magnetic head and a method of manufacturing the same of the invention to improve the insulating property between an electrode connected to a magnetoresistive element and a shield layer without increasing the thickness of an insulating layer between the magnetoresistive element and the shield layer. In the thin-film magnetic head, a bottom shield layer is formed into the shape of a frame having space in which conductive layers making up the electrode connected to an MR element are placed. The conductive layers are placed in the space (groove) of the bottom shield layer and insulated from the bottom shield layer while an insulating film is placed between the bottom shield layer and the conductive layers. The MR element is connected to the conductive layers through electrode layers.
    Type: Grant
    Filed: November 12, 1999
    Date of Patent: December 30, 2003
    Assignee: TDK Corporation
    Inventor: Yoshitaka Sasaki
  • Patent number: 6665154
    Abstract: Spin valve heads with overlaid leads have several advantages over butted contiguous junction designs, including larger signal output and better head stability. However, in any overlaid design there is always present at least one high resistance layer between the GMR layer and the conductive leads. This leads to an effective read width that is greater than the actual physical width. This problem has been overcome by inserting a highly conductive channeling layer between the GMR stack and the conducting lead laminate. This arrangement ensures that, at the intersection between the leads and the GMR stack, virtually all the current moves out of the free layer into the leads thereby providing an effective read width for the device that is very close to the physical read width defined by the spacing between the two leads. A process for manufacturing the device is also described.
    Type: Grant
    Filed: August 17, 2001
    Date of Patent: December 16, 2003
    Assignee: Headway Technologies, Inc.
    Inventors: Kochan Ju, You Feng Zheng, Rod Lee
  • Patent number: 6663986
    Abstract: A magneto-resistive (MR) stripe element includes a magnetically active body portion and a tri-layer electrical conductor structure arranged proximate the magnetically active body portion. The conductor structure has an alpha-Ta bi-layer film and a chromium capping layer. The alpha-Ta bi-layer film includes a chromium base layer and a tantalum layer. The capping layer caps the alpha-Ta bi-layer film such that the tantalum layer is disposed between the chromium base layer and the chromium capping layer. The tri-layer conductor structure has minimized compressive stress after deposition of the three layers and an even lower compressive stress after annealing. The thickness of the chromium capping layer is dependent at least upon the thickness of the chromium base layer such that the tri-layer conductor has a minimized compressive stress after deposition and annealing. The MR stripe element may be incorporated in a magnetic read head for reading data from a magnetic storage medium.
    Type: Grant
    Filed: December 27, 2001
    Date of Patent: December 16, 2003
    Assignee: Storage Technology Corporation
    Inventor: Steven Castle Sanders
  • Patent number: 6665153
    Abstract: A MR element is provided, which allows the sense current to flow through only the inner region of a MR layer to bypass its end regions, thereby realizing high magnetic sensitivity and good domain control in the sensing region.
    Type: Grant
    Filed: July 27, 2000
    Date of Patent: December 16, 2003
    Assignee: TDK Corporation
    Inventor: Kazuhiko Hayashi
  • Publication number: 20030227725
    Abstract: The magnetoresistive sensor has an MR stack and side shields formed by contacts and/or pedestals on either side of the MR stack. The materials for the contacts and pedestals are selected to be magnetically soft, electrically conductive and have a low AMR signal. The contacts and pedestals are magnetically decoupled from the hard bias materials by placement of spacers.
    Type: Application
    Filed: March 3, 2003
    Publication date: December 11, 2003
    Applicant: Seagate Technology LLC
    Inventors: Declan Macken, Michael K. Minor, Steven B. Slade, David J. Larson, Daniel J. Dummer