Plural Magnetic Deposition Layers Patents (Class 29/603.14)
  • Patent number: 6851178
    Abstract: One of the major requirements for higher frequency extendability is to reduce yoke length and inductance in order to have fast saturation. This has been accomplished by using a design that provides a cavity in the lower pole piece inside which is located at least two coils, one on top of the other. A process for manufacturing the device is also described.
    Type: Grant
    Filed: October 24, 2002
    Date of Patent: February 8, 2005
    Assignee: Headway Technologies, Inc.
    Inventors: Cherng Chyi Han, Mao-Min Chen, Pokang Wang, Yimin Guo
  • Patent number: 6848169
    Abstract: A fabrication method of a magnetic tunnel junction includes the steps of: forming a magnetic tunnel junction constructed having a first magnetic layer, a tunnel barrier formed at an upper surface of the first magnetic layer and a second magnetic layer formed at an upper surface of the tunnel barrier; and thermally treating the junction rapidly for 5 seconds˜10 minutes at a temperature of 200˜600° C. to re-distribute oxygens in the tunnel barrier and make the interface between the tunnel barrier and the magnetic layer to be even. The tunneling magnetoresistance and thermal stability of the magnetic tunnel junction can be improved through the rapid thermal annealing.
    Type: Grant
    Filed: May 13, 2002
    Date of Patent: February 1, 2005
    Assignee: Korea Institute of Science and Technology
    Inventors: Kyung-Ho Shin, Woo-Young Lee, Young-Joon Park, Kyung-Il Lee, Jae-Geun Ha
  • Patent number: 6849148
    Abstract: A magnetic tape head assembly is provided along with a method of manufacturing a magnetic tape head. The magnetic tape head comprises a cluster of thin film inductive or magnetoresistive read/write elements, an I-block preferably made of a ceramic material, a U-bar also preferably made of a ceramic material, and a base preferably made of a ceramic or metal material. The U-bar has a substantially U-shaped form providing a recess into which the I-block and the cluster are fixed. A bottom surface of the U-bar, I-block, and cluster is fixed to the base to form a slider assembly. A top surface of the U-bar, I-block, and cluster is machined or etched to form one or more tape bearing surfaces thereon.
    Type: Grant
    Filed: April 2, 2003
    Date of Patent: February 1, 2005
    Assignee: Lafe Technology Limited
    Inventor: Chuck Fai Lam
  • Patent number: 6842969
    Abstract: In magnetic read heads based on bottom spin valves the preferred structure is for the longitudinal bias layer to be in direct contact with the free layer. Such a structure is very difficult to manufacture. The present invention overcomes this problem by using a liftoff technique to form, on the free layer, a buffer layer having a trapezoidal cross-section, sloping sidewalls, and a central area of uniform thickness, whose width defines the read track. A suitable bias layer and leads are then deposited on this buffer layer.
    Type: Grant
    Filed: April 5, 2002
    Date of Patent: January 18, 2005
    Assignee: Headway Technologies, Inc.
    Inventors: Moris Dovek, Po-Kang Wang, Chen-Jung Chien, Chyu-Jiuh Torng, Yun-Fei Li
  • Publication number: 20040261254
    Abstract: On a surface of a bottom pole, a write gap film and first magnetic material film having a high saturation magnetic flux density are formed, and the first magnetic material film is etched to remain a portion extending from an air bearing surface to a throat height zero reference position and a first non-magnetic film is formed in a removed portion. The first non-magnetic material film is polished to obtain a flat surface which is coplanar with a surface of the first magnetic material film. A second magnetic material film having a high saturation magnetic flux density is formed on the flat surface. The second magnetic material film, first magnetic material film, write gap film and bottom pole are partially removed by RIE using a mask formed on the flat surface in accordance with a given pattern to form a track pole having a double-layer structure consisting of bottom and to track poles and a trim structure in a self-aligned manner.
    Type: Application
    Filed: June 8, 2004
    Publication date: December 30, 2004
    Applicants: HEADWAY TECHNOLOGIES, INC., SAE MAGNETICS (H.K.), LTD.
    Inventors: Yoshitaka Sasaki, Takehiro Kamigama
  • Publication number: 20040246631
    Abstract: The invention relates to a magnetoresistive device with a spin valve (1) formed from a stack of layers including at least two magnetic layers (2, 3) for which the relative orientation of their magnetisation directions can vary under the influence of a magnetic field, and comprising means (6a, 6b) of circulating a current in the spin valve transverse to the plane of the layers. The spin valve (1) comprises at least one discontinuous dielectric or semiconducting layer (4) in the stack, with electrically conducting bridges (5) passing through the thickness of the dielectric or semiconducting layer, these bridges (5) being designed to locally concentrate the current that passes transversely through the stack.
    Type: Application
    Filed: April 9, 2004
    Publication date: December 9, 2004
    Inventors: Bernard Dieny, Bernard Rodmacq, Franck Ernult
  • Publication number: 20040240121
    Abstract: A thin-film magnetic head having little temperature rise in the element, good heat dissipation and a short magnetic path length (narrow coil pitch) and manufacturing method for same is provided. To form the coil of the thin-film magnetic head, a lower coil is first formed and after forming alumina and an inorganic compound containing alumina, a trench is formed for the upper coil by reactive ion etching. The lower coil allows uniform etching at this time and functions as a film to prevent loading effects occurring during reactive ion etching. This trench is then plated in copper and chemical mechanical planarization performed to form the upper layer coil as the dual-layer coil of the present invention. Heat from the coil is efficiently radiated towards the substrate by alumina and an inorganic compound containing alumina with good heat propagation.
    Type: Application
    Filed: August 29, 2003
    Publication date: December 2, 2004
    Inventors: Kimitoshi Etoh, Nobuo Yoshida, Moriaki Fuyama, Makoto Morijiri, Kenichi Meguro, Ichiro Oodake, Kazue Kudo, Yohji Maruyama, Katsuro Watanabe
  • Patent number: 6820322
    Abstract: A method makes a spin valve sensor of a magnetic read head which includes the steps of forming a ferromagnetic pinned layer structure that has a magnetic moment, forming a pinning layer exchange coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure, forming a free layer structure, forming a nonmagnetic electrically conductive spacer layer between the free layer and the pinned layer structure and the forming of the free layer structure including the step of sputter depositing at least a first free layer composed of cobalt iron directly on the spacer layer in a nitrogen atmosphere.
    Type: Grant
    Filed: May 31, 2001
    Date of Patent: November 23, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Mustafa Pinarbasi
  • Patent number: 6817086
    Abstract: A bilayer mask employed for lift off has a top strip which bridges between first and second bilayer portions and is completely undercut so that when one or more materials is sputter deposited the materials do not form fences abutting recessed edges of a bottom layer in undercuts below a top layer. Sacrificial protective layers are formed on a sensor and lead layers for protecting these components while overlapping portions of these materials on the top of the sensor formed during deposition can be removed by ion beam sputtering, after which the sacrificial protective layers can be removed by ion milling or reactive ion etching.
    Type: Grant
    Filed: August 12, 2002
    Date of Patent: November 16, 2004
    Assignee: International Business Machines Corporation
    Inventors: Jennifer Qing Lu, Scott Arthur MacDonald, Hugo Alberto Emilio Santini
  • Publication number: 20040223267
    Abstract: A current-perpendicular-to the-plane (CPP) magnetoresistive device has two ferromagnetic layers separated by a nonmagnetic spacer layer with the free ferromagnetic layer having a central region of ferromagnetic material and nonmagnetic side regions formed of one or more oxides of the ferromagnetic material. One type of CPP device is a magnetic tunnel junction (MTJ) magnetoresistive read head in which the lower pinned layer has a width and height greater than the width and height, respectively, of the overlying central region of the upper free layer, with the side regions of the free layer being oxidized and therefore nonmagnetic. The MTJ read head is formed by patterning resist in the shape of the free layer central region over the stack of layers in the MTJ, ion milling or etching the stack down into the free layer, and then exposing the stack to oxygen to oxidize the ferromagnetic material in the side regions not covered by the resist.
    Type: Application
    Filed: June 15, 2004
    Publication date: November 11, 2004
    Inventors: Jeffrey R. Childress, Elizabeth A. Dobisz, Robert E. Fontana, Kuok San Ho, Ching Hwa Tsang, Son Van Nguyen
  • Patent number: 6810578
    Abstract: A method of manufacturing a thin film magnetic head. The method includes forming, near a pole portion: a first magnetic layer supported by a base substrate; a first insulating layer on the first magnetic layer with an end edge which forms a reference position for an air bearing surface; a gap layer on the pole portion of the first magnetic layer and the first insulation layer; a second magnetic layer that extends to a region beyond the pole portion; a thin film coil isolated by a second insulation layer located above the first insulation layer; a third magnetic layer on the second insulation layer. The air bearing surface is formed by grinding in part an end face of the pole portion of the first magnetic layer and an end face of the pole portion of the second magnetic layer and the gap layer placed therebetween.
    Type: Grant
    Filed: August 30, 2000
    Date of Patent: November 2, 2004
    Assignee: TDK Corporation
    Inventors: Yoshitaka Sasaki, Atsushi Iijima, Kazumasa Fukuda
  • Publication number: 20040205958
    Abstract: A method for fabricating a magnetic memory element structure comprises providing a dielectric layer having a conducting via. A first magnetic layer is formed overlying the dielectric layer and is in electrical communication with the conducting via. A non-magnetic layer and a second magnetic layer are formed overlying the first magnetic layer. A first conductive layer is deposited overlying the second magnetic layer and is patterned. A portion of the second magnetic layer is exposed and is transformed to form an inactive portion and an active portion. The active portion comprises a portion of a memory element and the inactive portion comprises an insulator. A sidewall spacer is formed about at least one sidewall of the first conductive layer and a masking tab is formed that overlies a portion of the memory element and extends to overlie at least a portion of the conducting via.
    Type: Application
    Filed: April 16, 2003
    Publication date: October 21, 2004
    Inventors: Gregory W. Grynkewich, Brian R. Butcher, Mark A. Durlam, Kelly Kyler, Kenneth H. Smith, Clarence J. Tracy
  • Publication number: 20040201070
    Abstract: The present invention seeks to reduce the amount of current required for a write operation by using a process for forming the read conductor within a recessed write conductor, the write conductor itself formed within a trench of an insulating layer. The present invention protects the MTJ from the voltages created by the write conductor by isolating the write conductor and enabling the reduction of current necessary to write a bit of information.
    Type: Application
    Filed: April 9, 2003
    Publication date: October 14, 2004
    Inventor: James G. Deak
  • Patent number: 6802114
    Abstract: A method of making a dual spin valve sensor includes the steps of forming first and second pinned layer structures, forming antiferromagnetic first and second pinning layers exchange coupled to the first and second pinned layer structures, forming an antiparallel (AP) coupled free layer structure between the first and second pinned layer structures, forming nonmagnetic conductive first and second spacer layers between the AP coupled free layer structure and the first and second pinned layer structures respectively, and a making of the AP coupled free layer structure includes the steps of forming ferromagnetic first, second and third antiparallel (AP) coupled free layers and forming a first antiparallel coupling layer between the first and second AP coupled free layers and a second antiparallel coupling layer between the second and third AP coupled free layers.
    Type: Grant
    Filed: September 11, 2003
    Date of Patent: October 12, 2004
    Assignee: International Business Machines Corporation
    Inventor: Hardayal Singh Gill
  • Publication number: 20040196596
    Abstract: Longitudinal biasing of a free layer in a current perpendicular to the planes of the layers (CPP) type of sensor in a read head is implemented by pinning magnetic moments of first and second side portions of the free layer beyond the track width of the read head with first and second insulating antiferromagnetic (AFM) layers which are exchange coupled thereto. The pinning of the magnetic moments of the first and second side portions of the free layer pin and longitudinally bias the central active portion of the free layer within the track width so that the central portion of the free layer is magnetically stable.
    Type: Application
    Filed: April 17, 2004
    Publication date: October 7, 2004
    Inventors: Kuok San Ho, Tao Pan
  • Publication number: 20040196595
    Abstract: A magnetic field sensor is described incorporating a plurality of magnetic stripes spaced apart on the surface of a substrate such that the stray magnetic fields at the ends of the magnetic stripes are magnetostatically coupled and the magnetic stripes are magnetized respectively in alternating directions, nonmagnetic conductive material positioned in the spaces between the magnetic stripes and electrodes for passing current crosswise through the plurality of magnetic stripes to detect a change in resistance by the giant magnetoresistive effect (MGR). The invention overcomes the problem of detecting low magnetic fields since the magnetic fields required to saturate magnetic stripes depends on the magnetostatic coupling which in turn can be controlled by the geometry and position of the magnetic stripes in the sensor.
    Type: Application
    Filed: April 19, 2004
    Publication date: October 7, 2004
    Inventors: Richard Joseph Gambino, Thomas Penney, John Casimir Slonczewski
  • Publication number: 20040190198
    Abstract: By inserting a first antistripping layer comprising a first non-magnetic layer 22 and a first conductive layer 23 between a first magnetic layer 16 and a magnetic separation layer 13, adhesion between the first conductive layer 23 and the magnetic separation layer 13 is improved to prevent the first magnetic layer 16 from stripping. In addition, by inserting a second antistripping layer comprising a second non-magnetic layer 24 and a second conductive layer 25 between a second magnetic layer 21 and a magnetic gap layer 17, adhesion between the second conductive layer 24 and the magnetic gap layer 17 is improved to prevent the second magnetic layer 25 from stripping.
    Type: Application
    Filed: March 31, 2004
    Publication date: September 30, 2004
    Inventors: Hiroaki Honjo, Tsutomu Ishi, Mikiko Saito, Shinsaku Saito, Tamaki Toba, Yoshihiro Nonaka, Kazuhiko Hayashi, Nobuyuki Ishiwata
  • Publication number: 20040179311
    Abstract: It has been found that the insertion of a copper laminate within CoFe, or a CoFe/NiFe composite, leads to higher values of CPP GMR and DRA. However, this type of structure exhibits very negative magnetostriction, in the range of high −10−6 to −10−5. This problem has been overcome by giving the copper laminates an oxygen exposure treatment When this is done, the free layer is found to have a very low positive magnetostriction constant. Additionally, the value of the magnetostriction constant can be adjusted by varying the thickness of the free layer and/or the position and number of the oxygen treated copper laminates.
    Type: Application
    Filed: March 12, 2003
    Publication date: September 16, 2004
    Applicant: Headway Technologies, Inc.
    Inventors: Min Li, Kunliang Zhang, Masashi Sano, Koichi Terunuma, Simon Liao, Kochan Ju
  • Patent number: 6785952
    Abstract: A first magnetic film, a gap film, a thin film coil supported by a insulated film and a second magnetic film are formed in turn. The second magnetic film has a pole part opposite to the first magnetic film via the gap film and a yoke part extending backward from the pole part to be magnetically connected to the first magnetic film. The forefront surface of the yoke part is receded from an air bearing surface. The pole part of the second magnetic film has a step d1 in a running direction of a magnetic recording medium and a step d2 in the perpendicular direction to the running direction within the yoke forefront surface and its periphery as is viewed from the yoke forefront surface. A protective film embeds the steps d1 and d2, and covers an inductive type thin film magnetic head element entirely. Thereby, without debasing the overwrite characteristic when the pole part is miniaturized, a thin film magnetic head having a narrowed track width can be provided.
    Type: Grant
    Filed: February 19, 2002
    Date of Patent: September 7, 2004
    Assignee: TDK Corporation
    Inventor: Akifumi Kamijima
  • Patent number: 6785954
    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: Grant
    Filed: April 17, 2002
    Date of Patent: September 7, 2004
    Assignee: 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: 6785953
    Abstract: A method of making a magnetic head, which has an air bearing surface (ABS) and a back gap (BG), comprising the steps of: forming a second pole tip of a second pole piece with a top surface and a bottom surface at an ABS site for said ABS; the top surface of the second pole tip having a write region located at the ABS site and a stitch region which is recessed in its entirety from the ABS site toward said back gap; depositing a protective sacrificial layer on the write region of the second pole tip; removing said sacrificial layer from only the stitch region of the second pole tip; and forming a second pole piece yoke of a second pole piece magnetically connected to the stitch region of the second pole tip.
    Type: Grant
    Filed: June 18, 2001
    Date of Patent: September 7, 2004
    Assignee: International Business Machines Corporation
    Inventor: Hugo Alberto Emilio Santini
  • Patent number: 6785955
    Abstract: A method and system for providing a writer is disclosed. The method and system include providing a first pole, an insulator covering a portion of the first pole and a coil on the first insulator. The coil includes a plurality of turns. The method and system also include providing a second insulator covering the coil, providing a second pole on the second insulator and providing a write gap separating a portion of the first pole from a second portion of the second pole. A first portion of the second pole is coupled with the first pole. In one aspect, the method and system include providing a coil having a plurality of turns with a pitch of no more than 1.2 micrometers. In another aspect, the plurality of turns of the coil is provided using a hard mask layer on a photoresist layer. A portion of the hard mask layer and a portion of the photoresist layer define a plurality of spaces between the pluralities of turns of the coil. In another aspect, the writer is a pedestal defined zero throat writer.
    Type: Grant
    Filed: January 23, 2001
    Date of Patent: September 7, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Yingjian Chen, Hugh Craig Hiner, Benjamin Chen, Xizeng Shi, Kyusik Sin
  • Publication number: 20040169964
    Abstract: A pinned layer structure of a spin valve sensor is formed by sputter deposition of cobalt iron (CoFe) in a nitrogen (N2) atmosphere. This method permits a wider range of deposition times of a copper spacer layer to achieve a desirable ferromagnetic coupling field (HF) between the pinned layer structure and a free layer structure in the spin valve sensor.
    Type: Application
    Filed: March 1, 2004
    Publication date: September 2, 2004
    Applicant: Hitachi Global Storage Technologies Netherlands B.V,
    Inventor: Mustafa Pinarbasi
  • Publication number: 20040168302
    Abstract: A method for manufacturing a thin-film magnetic head that reduces side fringing and realizes stable recording properties on a narrow track. The method includes sequentially depositing a first magnetic layer, a non-magnetic layer and a second magnetic layer. The method also includes a step of forming a three-layer pole tip structure located between an ABS and a position at a predetermined height from the ABS by ion milling using no reactive gas the first magnetic layer, the non-magnetic layer and the second magnetic layer. The non-magnetic layer is made of a material having an etching rate, for the ion milling using no reactive gas, equal to or higher than that of a material for making the first and second magnetic layers.
    Type: Application
    Filed: October 20, 2003
    Publication date: September 2, 2004
    Applicant: TDK Corporation
    Inventor: Tetsuya Mino
  • 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
  • Patent number: 6779249
    Abstract: A method for determining a characteristic of a magnetic head during its fabrication process on the surface of a wafer substrate. The method involves the fabrication of a test magnetic pole artifact in a field area of the substrate surface adjacent to the actual magnetic pole that is being fabricated. A test pole structure is fabricated simultaneously with, and utilizing the same fabrication conditions and parameters as, the actual pole such that the test pole is nearly identical to the actual pole. During a field etch step undertaken in the fabrication of the actual pole, portions of the test pole structure are removed, leaving a test pole artifact on the wafer surface. The test pole artifact can thus be easily measured as an accurate indication of characteristics of the actual magnetic pole that are difficult to measure directly, thereby saving time and expense in the magnetic head fabrication process.
    Type: Grant
    Filed: March 23, 2001
    Date of Patent: August 24, 2004
    Assignee: International Business Machines Corporation
    Inventor: Hugo Alberto Emilio Santini
  • Publication number: 20040160706
    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: Application
    Filed: February 20, 2004
    Publication date: August 19, 2004
    Inventors: Dallas W. Meyer, Tien-Chih Lin, Michael A. Stacy
  • Patent number: 6775903
    Abstract: A method for forming top and bottom spin valve sensors and the sensors so formed, the sensors having a strongly coupled SyAP pinned layer and an ultra-thin antiferromagnetic pinning layer. The two strongly coupled ferromagnetic layers comprising the SyAP pinned layer in the top valve configuration are separated by a Ru spacer layer approximately 3 angstroms thick, while the two layers in the bottom spin valve configuration are separated by a Rh spacer layer approximately 5 angstroms thick. This allows the use of an ultra thin MnPt antiferromagnetic pinning layer of thickness between approximately 80 and approximately 150 angstroms. The sensor structure produced thereby is suitable for high density applications.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: August 17, 2004
    Assignee: Headway Technolog
    Inventors: Cheng T. Horng, Kochan Ju, Mao-Min Chen, Min Li, Ru-Ying Tong, Simon Liao
  • Patent number: 6775902
    Abstract: A magnetic head is fabricated by providing a substrate with a planar surface, forming at least one cavity in the planar substrate, depositing a second yoke layer in the cavity, forming a second pole tip in the cavity in contact with the second yoke layer, patterning an inductive coil in the cavity, depositing a gap layer over the second pole tip, sputtering a first pole tip over the gap layer, etching the first and second pole tips and the gap layer to form a stack of layers, depositing a protective layer over the stack of layers, leveling the protective layer to expose the first pole tip, and patterning a first yoke layer in contact with the first pole tip.
    Type: Grant
    Filed: June 9, 2000
    Date of Patent: August 17, 2004
    Assignee: Western Digital (Fremont) Inc.
    Inventors: Yiming Huai, Durga P. Ravipati, Mark D. Thomas, Carlos Corona, William D. Jensen
  • Publication number: 20040156148
    Abstract: Side shield structures magnetically shielding a read sensor to block side reading of tracks on a magnetic media. The read heads include bottom and top magnetic shield layers, a read sensor or magnetically sensitive element between the bottom and top magnetic shield layers, and a side shield assembly formed of magnetically shielding material positioned between the bottom and top magnetic shield layers and adjacent at least a portion of the read sensor. In current-in-plane embodiments, the side shield assembly includes a pair of side shields of magnetically shielding material adjacent a lower portion of the read sensor formed on a lower read gap. In current-perpendicular-to-plane embodiments, the side shield assembly includes a pair of side shields extending from the bottom magnetic shield adjacent lower sides of the read sensor and/or a pair of side shields extending from the top magnetic shield adjacent upper sides of the read sensor.
    Type: Application
    Filed: February 11, 2003
    Publication date: August 12, 2004
    Inventors: Thomas Young Chang, Yingjian Chen, Jing Zhang, Heng Gong
  • Patent number: 6773515
    Abstract: A method for forming an NiCr seed layer based bottom spin valve sensor element having a synthetic antiferromagnet pinned (SyAP) layer and a capping layer comprising either a single specularly reflecting nano-oxide layer (NOL) or a bi-layer comprising a non-metallic layer and a specularly reflecting nano-oxide layer and the sensor element so formed. The method of producing these sensor elements provides elements having higher GMR ratios and lower resistances than elements of the prior art.
    Type: Grant
    Filed: January 16, 2002
    Date of Patent: August 10, 2004
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Simon H. Liao, Masashi Sano, Kiyoshi Noguchi, Kochan Ju, Cheng T. Horng
  • Publication number: 20040136121
    Abstract: A thermally stable spin valve sensor having an increased GMR ratio by virtue of an AP pinned layer structure in which the first and second pinned layers are separated by an AP coupling layer having a nano-oxide layer formed as an oxidized surface portion of the AP coupling layer. The nano-oxide layer provides an increase in the specular scattering, and in turn, an increase in the GMR ratio.
    Type: Application
    Filed: January 13, 2003
    Publication date: July 15, 2004
    Applicant: Veeco Instruments Inc.
    Inventors: Ming Mao, Adrian J. Devasahayam, Jacques C.S. Kools, Chih-Ling Lee, Chih-Ching Hu, Patricia L. Cox
  • 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
  • Patent number: 6757962
    Abstract: In a method for manufacturing a magnetic field sensing element including an electrode layer overlying a second antiferrogmagnetic layer and a first free magnetic layer where the electrode layer exposes a portion of the second magnetic layer, a portion of the second antiferromagnetic layer not covered with the electrode layer and a portion of the first free magnetic layer are removed using the electrode layer as a mask after laminating each layer to form a bottom type spin-valve thin film magnetic element, thereby enabling the first free magnetic layer to be endowed with a sufficient exchange coupling magnetic field by substantially eliminating the tapered portion of the remaining second antiferromagnetic layer thereby enabling the magnetization of the second free magnetic layer to be put into a single domain state.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: July 6, 2004
    Assignee: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Eiji Umetsu, Masamichi Saito, Kenichi Tanaka, Yosuke Ide
  • Patent number: 6754947
    Abstract: A process of forming a two-piece pole for an inductive write head involves first forming a first pole piece having a width between opposite side surfaces defining a gap width of a transducing gap at an air bearing surface of the head. The process next involves forming a second pole piece having a first region remote from the air bearing surface and a second region extending from the first region toward the air bearing surface. The first region is wider than the width of the first pole piece. The second pole piece is formed so that at least a portion of the second region is contiguous a portion of the first pole piece and so that no sharp external corners exist between the first pole tip piece and the second pole piece within a pole tip region of the head.
    Type: Grant
    Filed: August 13, 2001
    Date of Patent: June 29, 2004
    Assignee: Seagate Technology LLC
    Inventors: Frank E. Stageberg, Kenneth P. Ash, James K. Price, Feng Wang, Elzbieta J. Haftek, Allan E. Schultz, Richard P. Larson
  • Publication number: 20040120082
    Abstract: A method and apparatus for enhancing thermal stability, improving biasing and reducing damage from electrical surges in self-pinned abutted junction heads. The head includes a free layer having a first end and a second end defining a width selected to form a desired trackwidth and an extended self-pinned bias layer extending beyond the ends of the free layer, the self-pinned bias layer extending beyond the free layer increasing the volume of the extended self-pinned bias layer to provide greater thermal stability and stronger pinning of the free layer.
    Type: Application
    Filed: July 29, 2003
    Publication date: June 24, 2004
    Applicant: Sony Corporation
    Inventors: Tomohiro Ikegami, Yutaka Okazaki
  • Patent number: 6751846
    Abstract: A method for manufacturing a magnetic head which includes a lower write pole having a projection, an upper write pole having a projection opposed to the projection of the lower write pole, and a magnetic gap interposed between the projection of the upper write pole and the projection of the lower write pole, comprising: a first step of making the magnetic gap on the projection of the lower write pole; a second step of making a non-magnetic material layer on the lower write pole, the non-magnetic material layer having a projection on its top surface in positional alignment with the projection of the lower write pole; a third step of making a mask layer on the non-magnetic material layer, the mask layer having an opening in which the top surface of the projection of the non-magnetic material layer is exposed; a fourth step of making a curved recess in the non-magnetic material layer by isotropically etching the non-magnetic material layer through the opening of the mask layer; a fifth step of making an approxim
    Type: Grant
    Filed: March 31, 2003
    Date of Patent: June 22, 2004
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Susumu Hashimoto, Michiko Hara, Tomohiko Nagata, Kohichi Tateyama, Masatoshi Yoshikawa, Takeo Sakakubo, Hiroaki Yoda, Akio Hori, Takashi Koizumi
  • Patent number: 6751845
    Abstract: A spin valve sensor with a continuous junction is provided which has a sensor portion of a free layer longitudinally biased by first and second AFM biasing layers that are exchange coupled to first and second side portions of the free layer and a sensor portion of an AFM pinning layer that pins a sensor portion of a pinned layer perpendicular to the ABS in either a top spin valve or a bottom spin valve sensor.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: June 22, 2004
    Assignee: International Business Machines Corporation
    Inventor: Hardayal Singh Gill
  • Patent number: 6751844
    Abstract: A spin valve sensor has a pinned layer structure that has a net positive stress induced uniaxial anisotropy that promotes a pinning of the pinned layer structure in a pinned direction for stabilizing the pinning of the pinned layer structure at high temperatures near to a blocking temperature of a pinning layer which is exchange coupled to the pinned layer.
    Type: Grant
    Filed: June 11, 2001
    Date of Patent: June 22, 2004
    Assignee: International Business Machines Corporation
    Inventor: Mustafa Pinarbasi
  • Publication number: 20040114281
    Abstract: A method for forming a planar GMR read-head having a narrow read gap, a narrow track-width and being well insulated from its lower shield. The method requires the formation of a planarized bottom magnetic shield in which concave regions, symmetrically disposed about a track-width region, are filled with a layer of dielectric to provide added insulation. The dielectric filled shield is planarized and an additional planar dielectric layer, a thin planar GMR sensor layer and a planar PMGI layer of uniform thickness is formed on it. A layer of photoresist is deposited on the PMGI layer and a bi-layer lift-off stencil of uniform height above the GMR layer and symmetric overhang regions is formed. The uniformity of the lift-off stencil, which is a result of the planarity of the layers on which it is formed, allows the deposition of conductive lead and biasing layers with controlled overspread.
    Type: Application
    Filed: December 13, 2002
    Publication date: June 17, 2004
    Applicant: Headway Technologies, Inc.
    Inventors: Cherng Chyi Han, Mao-Min Chen, Jiun-Ting Lee
  • Publication number: 20040105193
    Abstract: A novel seed layer comprising an approximately 30 angstrom thick layer of NiCr whose atomic percent of Cr is 31%, is used to form a single bottom spin valve read sensor and a symmetric dual spin valve read sensor having synthetic antiferromagnetic pinned layers. The seed layer permits the use of extremely thin (approximately 80 angstroms) MnPt pinning layers as well as extremely thin pinned and free layers so that the sensors can be used to read recorded media with densities exceeding 60 Gb/in2. Moreover, the high pinning field and optimum magnetostriction produces an extremely robust sensor.
    Type: Application
    Filed: December 3, 2002
    Publication date: June 3, 2004
    Applicant: Headway Technologies, Inc.
    Inventors: C.T. Horng, Hui-Chuan Wang, Ru-Ying Tong, Chyu-Jiuh Trong
  • Publication number: 20040105192
    Abstract: The possibility of shorting between a spin valve and its underlying magnetic shield layer can be largely eliminated by choosing the bottom spin valve structure. However, doing so causes the hard longitudinal bias that is standard for all such devices to degrade. The present invention overcomes this problem by inserting a thin NiCr, Ni, Fe, or Cr layer between the antiferromagnetic layer and the longitudinal bias layers. This provides a smoother surface for the bias layers to be deposited onto, thereby removing structural distortions to the longitudinal bias layer that would otherwise be present. A process for manufacturing the structure is also described.
    Type: Application
    Filed: November 21, 2003
    Publication date: June 3, 2004
    Applicant: HEADWAY TECHNOLOGIES, INC.
    Inventors: Chen-Jung Chien, Chyu-Jiuh Torng, Cherng-Chyi Han, Moris Dovek, Po-Kang Wang, Mao-Min Chen
  • Patent number: 6742241
    Abstract: To provide a method of manufacturing a thin film magnetic head capable of realizing an accurate control of a pole width and a sufficient overwrite characteristic even when the pole width is narrowed. In a connecting portion of an intermediate portion and a tip portion in a top pole, a step face in a width direction of almost the right angle is provided. The step face has a first corner at an intersection portion between the step face and a side face in the tip portion. A positive photoresist is used for a photolithography process to form the top pole. A photomask used at the time of exposure includes a projection in a shape having an acute angle portion in a portion corresponding to the first corner in the top pole. Consequently, a wedge-shaped recess is formed in the first corner in the top pole. Thus, even when the throat height is changed, the recording track width is not changed and the recording track width can be prevented from being widened.
    Type: Grant
    Filed: July 3, 2000
    Date of Patent: June 1, 2004
    Assignee: TDK Corporation
    Inventor: Yoshitaka Sasaki
  • Patent number: 6735850
    Abstract: The present invention provides an improved bias magnet-to-magnetoresistive element interface and method of fabrication. In a preferred embodiment, the wall/walls of an MR element opposing a bias layer are formed by over etching to provide vertical side walls without taper. In the preferred embodiment, a protective element is formed over the MR element to protect it during etch processes. In some embodiments, a filler layer is deposited prior to bias layer formation. In CIP embodiments, any portion of the filler layer forming on vertical side walls of the MR element is etched to provide an exposed side wall surface for contiguous bias layer formation. In CPP embodiments, the filler layer forms on a vertical back wall and electrically insulates the MR element from the bias layer.
    Type: Grant
    Filed: May 20, 2002
    Date of Patent: May 18, 2004
    Assignee: Western Digital (Fremont), Inc.
    Inventors: Matthew Gibbons, Kenneth E. Knapp, Ronald A. Barr, Benjamin P. Law, James Spallas, Ming Zhao
  • Patent number: 6738232
    Abstract: An object of the invention is to provide thin-film magnetic heads that meet specifications required by the customer in a short time and to improve yields of the thin-film magnetic heads. A reproducing head of a thin-film magnetic head includes an MR element and a bottom shield layer and a top shield layer. A recording head of the thin-film magnetic head includes a bottom pole layer (top shield layer) and a top pole layer which include pole portions opposed to each other while a recording gap layer is placed between the pole portions. The recording head further includes a thin-film coil placed between the bottom pole layer and the top pole layer. The top shield layer includes: a first portion placed in a region including a region facing the thin-film coil; a second portion connected to a surface of the first portion facing the coil and placed on a side of a bottom shield layer; and a third portion connected to the second portion and facing the bottom shield layer with the MR element in between.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: May 18, 2004
    Assignee: TDK Corporation
    Inventor: Yoshitaka Sasaki
  • Patent number: 6732421
    Abstract: A method for producing magnetoresistive heads includes the steps of placing a substrate having a plurality of transducers in an environment including a focused ion beam. The focused ion beam is directed onto the first MR element. A property level, generally the resistance associated with the MR stripe, of the first MR element is monitored until the resistance reaches a desired level. The focused ion beam is redirected onto a second area of the substrate which includes the second MR element. The electrical resistance of the second MR element is monitored as the focused ion beam acts on the second MR element until the resistance of the MR element reaches a desired level. Using this process, the resistivity of individual MR elements within the substrate can be tightly controlled.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: May 11, 2004
    Assignee: Seagate Technology LLC
    Inventors: Jane K. Gates, Jeffery K. Berkowitz, Lance E. Stover
  • Patent number: 6729012
    Abstract: A method of manufacturing a thin-film magnetic head comprises the steps of forming a bottom pole layer, forming a gap layer, forming a top pole layer, and forming a thin-film coil. The thin-film coil is wound around the top pole layer in a helical manner. In the step of forming the bottom pole layer, the bottom pole layer is formed to include a first layer facing a portion of the thin-film coil, and a second layer that forms a pole portion and is connected to a surface of the first layer facing the top pole layer. In the step of forming the thin-film coil, a portion of the coil is disposed on a side of the second layer and another portion of the coil is disposed over the top pole layer via an insulating film.
    Type: Grant
    Filed: April 14, 2000
    Date of Patent: May 4, 2004
    Assignee: TDK Corporation
    Inventor: Yoshitaka Sasaki
  • Patent number: 6729014
    Abstract: A method for forming a top spin-valve SyAP GMR read sensor having a novel conductive lead overlay configuration and the sensor so formed. The lead overlay electrically contacts the sensor at a position within the SyAP pinned layer, thus simultaneously assuring improved electrical contact and destroying the GMR properties of the sensor at the junction to improve the definition of the sensor track width.
    Type: Grant
    Filed: September 17, 2001
    Date of Patent: May 4, 2004
    Assignee: Headway Technologies, Inc.
    Inventors: Charles C. Lin, Cheng T. Horng, Min Li, Kochan Ju
  • Publication number: 20040078959
    Abstract: A method of adjusting or locally modifying the direction of magnetization of a ferromagnetic layer in a magnetoresistive layer system using a heat stamp is described, the ferromagnetic layer being stabilized over an antiferromagnetic layer. The antiferromagnetic layer is heated, using a heat stamp, over a threshold temperature, above which the influence of this layer on the direction of magnetization of the adjacent ferromagnetic layer disappears; subsequently, the ferromagnetic layer is exposed to an external magnetic field of a predefined direction, and finally the antiferromagnetic layer is cooled again below the threshold temperature. In addition, a heat stamp having a base body and a heatable stamp structure connected to the base body and matching the dimensions of or similar to the magnetoresistive layer system is described.
    Type: Application
    Filed: July 7, 2003
    Publication date: April 29, 2004
    Inventors: Henrik Siegle, Andrew Johnson, Ulrich May
  • Patent number: 6725527
    Abstract: A magnetic head assembly has an open yoke type write head constructed on top of a read head so that the write head can be constructed with a very narrow track width without restraint by the requirements of the read head. The write head has first and second pole piece portions wherein the second pole piece portion has separate front and back layer portions. A coil layer is wrapped around only the first pole piece portion and the back layer portion so that the front layer portion can be constructed separately to provide a narrow track width. Further, in a preferred embodiment the front layer portion has a reduced thickness and a higher magnetic moment than the thickness and magnetic moment of the first pole piece portion and the back layer portion. Still further, in a preferred embodiment the first pole piece portion and the back layer portion are planar due to polarization of underlying layers.
    Type: Grant
    Filed: July 18, 2001
    Date of Patent: April 27, 2004
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Thomas Young Chang, Glen Adam Garfunkel, Edward Hin Pong Lee, Neil Leslie Robertson, Samuel Wonder Yuan