Having One Film Pinned (e.g., Spin Valve) Patents (Class 360/324.1)
  • Publication number: 20030184921
    Abstract: The present invention provides a magnetoresistive (MR) element that is excellent in MR ratio and thermal stability and includes at least one magnetic layer including a ferromagnetic material M—X expressed by M100−aXa. Here, M is at least one selected from Fe, Co and Ni, X is expressed by X1bX2cX3d (X1 is at least one selected from Cu, Ru, Rh, Pd, Ag, Os, Ir, Pt and Au, X2 is at least one selected from Al, Sc, Ti, V, Cr, Mn, Ga, Ge, Y, Zr, Nb, Mo, Hf, Ta, W, Re, Zn and lanthanide series elements, and X3 is at least one selected from Si, B, C, N, O, P and S), and a, b, c and d satisfy 0.05≦a≦60, 0≦b≦60, 0≦c≦30, 0≦d≦20, and a=b+c+d.
    Type: Application
    Filed: February 19, 2003
    Publication date: October 2, 2003
    Inventors: Yasunari Sugita, Masayoshi Hiramoto, Nozomu Matsukawa, Mitsuo Satomi, Yoshio Kawashima, Akihiro Odagawa
  • Publication number: 20030179496
    Abstract: A read sensor and method of making the same using an etch-stop layer are disclosed. The method is particularly suitable in connection with techniques requiring the partial removal of the capping layer, such as exchange tab (ET) and lead overlay (LOL) techniques. Basically, a thin “etch-stop” layer is deposited over a top free layer of sensor materials. The etch-stop layer is made of a suitable material such as copper oxide (CuO) or nickel-iron-chromium (NiFeCr). A tantalum (Ta) capping layer is then deposited over the etch-stop layer. When appropriate, top edge portions of the capping layer are exposed to a reactive ion etch (RIE) using a fluorine gas for removal. Advantageously, the etch-stop layer significantly reduces or eliminates damage to the free layer that would otherwise occur due to the fluorine gas RIE.
    Type: Application
    Filed: March 22, 2002
    Publication date: September 25, 2003
    Inventor: Wipul Pemsiri Jayasekara
  • Publication number: 20030179510
    Abstract: The disclosed invention provides a magnetic recording apparatus with a magnetic reading head fabricated with a high-output magnetoresistive element and random access magnetic memory devices with a function of reversing the direction of magnetization by means for injecting highly spin-polarized electrons. The magnetoresistive element is a three-terminal giant magnetoresistive element integral with the means for injecting highly spin-polarized electrons into the element. By using this element, the following can be realized: magnetic recording and reproducing apparatus with a magnetic head that is able to read higher-output reproducing signals; and random access magnetic memory devices which feature the function of reversing the direction of magnetization without using a magnetic field produced by current flowing across the device and can be high densely integrated with ease.
    Type: Application
    Filed: February 26, 2003
    Publication date: September 25, 2003
    Applicant: Hitachi, Ltd.
    Inventor: Jun Hayakawa
  • Patent number: 6624985
    Abstract: A CPP geometry spin valve sensor for sensing magnetically recorded information on a data storage medium includes an electrically conductive, multilevel seed layer that interfacially engages a pinning layer of the sensor and increases the sensor's magnetoresistance while maintaining acceptable values of free layer coercivity, pinned-free layer magnetic coupling and free layer magnetostriction.
    Type: Grant
    Filed: January 7, 2002
    Date of Patent: September 23, 2003
    Assignee: International Business Machines Corporation
    Inventors: James Mac Freitag, Mustafa Pinarbasi
  • Publication number: 20030174447
    Abstract: A spin valve type magnetoresistive element includes a substrate, an under layer deposited on the substrate, and a sensor portion arranged on the under layer. The under layer is formed of an amorphous CoNbZr alloy. The sensor portion includes a first ferromagnetic layer in which a magnetizing direction is changed by application of a magnetic field, a second ferromagnetic layer in which a magnetizing direction is fixed, a spacer layer which is non-magnetic and arranged between the first ferromagnetic layer and the second ferromagnetic layer, and an antiferromagnetic layer which is arranged to be adjacent to the second ferromagnetic layer to fix the magnetizing direction of the second ferromagnetic layer.
    Type: Application
    Filed: January 3, 2003
    Publication date: September 18, 2003
    Applicant: Korea Chungangeducational Foundation
    Inventors: Seong-Rae Lee, Ho-Gun Cho
  • Patent number: 6621100
    Abstract: This invention relates to organic based spintronic devices, and electronic devices comprising them, including spin valves, spin tunnel junctions, spin transistors and spin light-emitting devices. New polymer-, organic- and molecular-based electronic devices in which the electron spin degree of freedom controls the electric current to enhance device performance. Polymer-, organic-, and molecular-based spintronic devices have enhanced functionality, ease of manufacture, are less costly than inorganic ones. The long spin coherence times due to the weak spin-orbit interaction of carbon and other low atomic number atoms that comprise organic materials make them ideal for exploiting the concepts of spin quantum devices. The hopping mechanism of charge transport that dominates in semiconducting polymers (vs. band transport in crystalline inorganic semiconductors) enhances spin-magneto sensitivity and reduces the expected power loss.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: September 16, 2003
    Assignee: The Ohio State University
    Inventors: Arthur J. Epstein, Vladimir N. Prigodin
  • Patent number: 6621667
    Abstract: A giant magnetoresistive spin valve for use in a magnetic read head includes a ferromagnetic free layer and a multilayer cap layer. The free layer has a rotatable magnetic moment. The multilayer cap layer is positioned adjacent to the free layer for increasing electron specular scattering of the free layer.
    Type: Grant
    Filed: July 18, 2001
    Date of Patent: September 16, 2003
    Assignee: Seagate Technology LLC
    Inventors: Qing He, Song S. Xue, Xuefei Tang, Bryan K. Oliver, Patrick J. Ryan
  • Publication number: 20030169541
    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 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: Application
    Filed: March 7, 2002
    Publication date: September 11, 2003
    Applicant: Headway Technologies, Inc.
    Inventors: Moris M. Dovek, Tai Min
  • Patent number: 6614629
    Abstract: The present invention provides a thin film magnetic head which is prevented from producing a great step in an upper shield layer and which can decrease the probability of a short circuit between the upper shield layer or lower shield layer and a spin-valve thin film magnetic element. The thin film magnetic head includes a spin-valve thin film magnetic element including a lamination of a free magnetic layer, a nonmagnetic conductive layer, a pinned magnetic layer, and an antiferromagnetic layer, a pair of conductive layers for supplying a sensing current to the free magnetic layer, and a pair of insulating bias layers for orienting the magnetization direction of the free magnetic layer; and a pair of shield layers laminated on both sides of the spin-valve thin film magnetic element in the direction of the thickness thereof.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: September 2, 2003
    Assignee: Alps Electric Co., Ltd.
    Inventor: Yoshihiko Kakihara
  • Publication number: 20030161077
    Abstract: In the present invention, a thin film whose main component is a metal having a specific resistance of 4 &mgr;&OHgr;·cm to 200 &mgr;&OHgr;·cm is used as a nonmagnetic layer of a so-called CPP-GMR element. Therefore, even when an area of the element becomes limited, the element is not increased excessively in resistance. Thus, even when a magnetic gap is narrow, a large output can be obtained.
    Type: Application
    Filed: April 4, 2003
    Publication date: August 28, 2003
    Inventors: Yasuhiro Kawawake, Yasunari Sugita, Hiroshi Sakakima
  • Patent number: 6606782
    Abstract: To form a spin valve device, start by forming a gap layer. Form a buffer layer with a layer of refractory material on the buffer layer. Form patterned underlayers including a magnetic material for providing trackwidth and longitudinal bias on the buffer layer comprising either a lower antiferromagnetic layer stacked with a ferromagnetic layer or a Cr layer stacked with a permanent magnetic layer. Form an inwardly tapered depression in the patterned underlayers down to the buffer layer by either ion milling through a mask or a stencil lift off technique. Form layers covering the patterned underlayers that cover the inwardly tapered depression. Form free, pinned, spacer and antiferromagnetic layers. Form conductors either on a surface of the antiferromagnetic layer aside from the depression or between the buffer layer and the patterned underlayers.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: August 19, 2003
    Assignee: Headway Technologies, Inc.
    Inventors: Tai Min, Po-Kang Wang, Moris Musa Dovek
  • Patent number: 6603677
    Abstract: A magnetic device including at least a memory cell having a first magnetic layer with a fixed magnetization direction. The first magnetic layer spin polarizes a writing current of electrons. The memory cell includes a second magnetic layer having a three-layered stack with a variable magnetization direction. An insulating or semi-conduction layer is formed between the first and second magnetic layers. The variable magnetization direction is oriented by spins of a spin polarized writing current. The three-layered stack includes two magnetic layers separated by a non-magnetic conducting layer. The first magnetic layer aligns the variable magnetization direction with the fixed magnetization direction by directing an incident writing current of electrons perpendicular through the first magnetic layer and then perpendicular through the second magnetic layer.
    Type: Grant
    Filed: November 20, 2001
    Date of Patent: August 5, 2003
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Olivier Redon, Bernard Dieny, Bernard Rodmacq
  • Patent number: 6599401
    Abstract: Uniaxial magnetic anisotropy was found in the Fe/Co/Cu/Co magnetoresistive structures deposited on Si (100) substrates. Samples magnetized along an easy anisotropy axis showed extremely sharp magnetization and magnetoresistance switching at low fields and maximum giant magnetoresistance of 9.5% at 5K (5.5% at room temperature) for the samples with 5 nm of Fe,5 nm of Co, 2.5 nm of Cu and 2 nm of Co. These results were advantageous compared to Co/Cu/Co trilayers grown on Cr/Cu buffer which did not exhibit uniaxial anisotropy. Deposition on spinning wafers allowed excluding substrate related anisotropy. An existing magnetic field in the magnetron sputtering system with the strength of 32 Oe at the sample location was found the most probable source of the induced uniaxial anisotropy.
    Type: Grant
    Filed: March 19, 2001
    Date of Patent: July 29, 2003
    Assignee: University of New Orleans Research and Technology Foundation, Inc.
    Inventors: Jian-Qing Wang, Leszek M. Malkinski
  • Publication number: 20030133232
    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: Application
    Filed: January 16, 2002
    Publication date: July 17, 2003
    Applicant: Headway Technologies, Inc.
    Inventors: Min Li, Simon H. Liao, Masashi Sano, Kiyoshi Noguchi, Kochan Ju, Cheng T. Horng
  • Patent number: 6591479
    Abstract: A production method for a spin-valve type magnetoresistive element comprising laminating an antiferromagnetic layer, a pinned magnetic layer, a non-magnetic electrically conductive layer, a free magnetic layer, and a second antiferromagnetic layer. The second antiferromagnetic layer is located on the free magnetic layer and orients the magnetization direction of the free magnetic layer. In this method, a first thermal treatment is performed at a first temperature of ordering a crystal structure of the first antiferromagnetic layer or at a second temperature lower than a second blocking temperature of the second antiferromagnetic layer. After the first thermal treatment, a second thermal treatment is performed at a third temperature lower than a first blocking temperature of the first antiferromagnetic layer but higher than said second blocking temperature of the second antiferromagnetic layer.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: July 15, 2003
    Assignee: Alps Electric Co., Ltd.
    Inventors: Yukie Nakazawa, Masamichi Saito, Naoya Hasegawa, Akihiro Makino
  • Publication number: 20030128481
    Abstract: A current-perpendicular-to-the-plane (CPP) structure magnetoresistive element includes a spin valve film. A boundary is defined between electrically-conductive layers included in a non-magnetic intermediate layer in the spin valve film. A magnetic metallic material and an insulating material exist on the boundary. The insulating material serves to reduce the sectional area of the path for the sensing electric current. The CPP structure magnetoresistive element realizes a larger variation in the electric resistance in response to the rotation of the magnetization in the free magnetic layer. A sensing electric current of a smaller level is still employed to obtain a sufficient variation in the voltage. Accordingly, the CPP structure magnetoresistive element greatly contributes to a further improvement in the recording density and reduction in the electric consumption.
    Type: Application
    Filed: December 19, 2002
    Publication date: July 10, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Yoshihiko Seyama, Keiichi Nagasaka, Hirotaka Oshima, Yutaka Shimizu, Atsushi Tanaka
  • Patent number: 6590750
    Abstract: Magnetoresistive devices are disclosed which include a changeable magnetic region within which at least two magnetic states can be imposed. Upon magnetoresistive electrical interaction with the device, the relative orientation of the magnetic states of the changeable magnetic region, and a proximate reference magnetic region, can be sensed thereby providing a binary data storage capability. The present invention limits the electrical interaction to only a preferred portion of the changeable magnetic region, e.g., the portion within which the two magnetic states can be dependably predicted to be substantially uniform, and opposite of one another. Structures for limiting the electrical interaction to this preferred portion of the changeable magnetic region are disclosed, and include smaller interaction regions, and alternating areas of insulation and conductive, interaction regions, disposed proximate the changeable magnetic region.
    Type: Grant
    Filed: February 10, 1998
    Date of Patent: July 8, 2003
    Assignee: International Business Machines Corporation
    Inventors: David William Abraham, Philip Edward Batson, John Slonczewski, Philip Louis Trouilloud, William Joseph Gallagher, Stuart Parkin
  • Publication number: 20030123200
    Abstract: A magnetoresistive element that detects a change of magnetoresistance by giving a sense current in the thickness direction of a magnetoresistive effect film including at least a base layer, a free layer, a non-magnetic layer, a pinned layer, a pinning layer, and a protection layer, includes a granular structure layer that includes conductive particles and an insulating matrix material in the form of a thin film containing the conductive particles in a dispersed state and having a smaller thickness than the particle diameter of the conductive particles, the granular structure layer being interposed between at least two adjacent layers among the base layer, the free layer, the non-magnetic layer, the pinned layer, the pinning layer, and the protection layer.
    Type: Application
    Filed: October 16, 2002
    Publication date: July 3, 2003
    Applicant: FUJITSU LIMITED
    Inventors: Keiichi Nagasaka, Yoshihiko Seyama, Takahiko Sugawara, Yutaka Shimizu, Atsushi Tanaka
  • Patent number: 6587316
    Abstract: The relation of (RS1/H1)/(Rsg/Hg)≦0.02 is valid when the extending length in the vertical direction from an opposed face to an magnetic recording medium toward the inside of the electrode layer is represented by H1, a sheet resistance of the electrode layer is defined by Rs1, the extending length in the vertical direction from an opposed face to an magnetic recording medium toward the inside of the laminated body, or the elevation of the element, is defined by Hg, and the sheet resistance of the laminated body is defined by Rsg, thereby the output characteristics of the spin-valve type thin film magnetic element is improved while preventing side-reading from generating.
    Type: Grant
    Filed: August 21, 2001
    Date of Patent: July 1, 2003
    Assignee: Alps Electric Co., Ltd.
    Inventor: Naoya Hasegawa
  • Patent number: 6580270
    Abstract: A sensor (MRE) or memory element (ME) having a free (1, 2, 3) and a pinned (Mp, 6) magnetic layer separated by a separation layer (5). The free layer comprises a sandwich structure comprising two magnetic layers (1,2), coupled anti-ferromagneticallly by a thin non-magnetic layer (3), the easy magnetization direction for the two magnetic layers being directed transversely to the longitudinal axis (1) of the stripe.
    Type: Grant
    Filed: September 7, 2000
    Date of Patent: June 17, 2003
    Assignee: Koninklijke Philips Electronics N.V.
    Inventor: Reinder Coehoorn
  • Patent number: 6580588
    Abstract: A dual spin valve sensor is provided which includes a ferromagnetic free layer, first and second antiparallel (AP) pinned layer structures, a nonmagnetic conductive first spacer layer between the free layer and the first AP pinned layer structure, a nonmagnetic conductive second spacer layer between the free layer and the second AP pinned layer structure, an antiferromagnetic first pinning layer exchange coupled to the first AP pinned layer structure for pinning a magnetic moment of the first AP pinned layer structure in a first direction and an antiferromagnetic second pinning layer exchange coupled to the second AP pinned layer for pinning a magnetic moment of the second AP pinned layer structure in a second direction.
    Type: Grant
    Filed: October 6, 2000
    Date of Patent: June 17, 2003
    Assignee: International Business Machines Corporation
    Inventor: Hardayal Singh Gill
  • Publication number: 20030107849
    Abstract: A unit element of a magnetic device or a ferroelectric device and magnetic particles of a magnetic recording medium are provided. The outline of the unit element and the magnetic particles is arranged so as to have a portion topologically identical to one of a letter-C shape and a letter-S shape that correspond to the magnetization or polarization distribution immediately before the rotation of magnetization or polarization.
    Type: Application
    Filed: September 2, 2002
    Publication date: June 12, 2003
    Inventor: Minoru Ikarashi
  • Publication number: 20030107850
    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: Application
    Filed: January 6, 2003
    Publication date: June 12, 2003
    Applicant: Alps Electric Co., Ltd.
    Inventors: Daigo Aoki, Naoya Hasegawa, Kenji Honda, Yoshihiko Kakihara
  • Publication number: 20030103298
    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: Application
    Filed: January 6, 2003
    Publication date: June 5, 2003
    Applicant: Alps Electric Co., Ltd.
    Inventors: Kenji Honda, Kiyoshi Sato, Yoshihiko Kakihara
  • Publication number: 20030095362
    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: Application
    Filed: January 6, 2003
    Publication date: May 22, 2003
    Applicant: Alps Electric Co., Ltd.
    Inventors: Daigo Aoki, Naoya Hasegawa, Kenji Honda, Yoshihiko Kakihara
  • Patent number: 6567244
    Abstract: A read head, which has an air bearing surface (ABS), includes a yoke which has first and second legs which are interconnected at a location within the head at a distance d1 from the ABS wherein the first and second legs have first and second end edges respectively which are located at the ABS and spaced apart by a distance d2. The first and second legs have first and second separations respectively which are located between the ABS and the distance d1 and which magnetically and electrically disconnect leg portions of each leg. The first sensor is magnetically and electrically connected to the first leg across a first separation and a second sensor is magnetically and electrically connected to the second leg across the second separation. The first sensor has a first pinned layer structure and the second sensor has a second pinned layer structure wherein the first and second pinned layer structures have first and second magnetic moments respectively that are antiparallel with respect to each other.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: May 20, 2003
    Assignee: Hitachi Global Storage Technologies Netherlands
    Inventor: Hardayal Singh Gill
  • Patent number: 6560077
    Abstract: A spin-valve device of a CPP structure which has a high resistance, and which generates a high output signal with low current. The CPP spin-valve device including a spin-valve element having a substrate and a layered structure formed on the substrate. The layered structure includes a first thin film layer of ferromagnetic material, a second thin film layer of ferromagnetic material, and a thin non-magnetic layer structure separating the first and second layers. One of the first and second thin film layers is defined as a free layer and the other layer is defined as a pinned layer, where the free layer has a direction of magnetization that is easier to change than a direction of magnetization of the pinned layer by application of a magnetic field. The non-magnetic layer structure includes a conducting part and insulating part, with the conduction part having an area that is smaller than an area of the free layer.
    Type: Grant
    Filed: January 10, 2000
    Date of Patent: May 6, 2003
    Assignee: The University of Alabama
    Inventors: Hideo Fujiwara, Gary J. Mankey
  • Patent number: 6556390
    Abstract: The present invention comprises a magnetoresistive sensor including a cap layer, a free layer, a spacer layer, a pinned layer, an oxide layer, a pinning layer, a seed layer, and a substrate layer. The sensor consists of the cap layer adjacent the free layer. The free layer is adjacent to the spacer layer. The spacer layer is adjacent to the pinned layer. The pinned layer is adjacent to the oxide layer. The oxide layer is adjacent to the pinning layer. The pinning layer is adjacent to the seed layer and the seed layer is adjacent to the substrate. The present invention also comprises a method of manufacturing the magnetoresistive sensor including forming a layered structure. An electron specular scattering effect occurs at the oxide interface to achieve enhanced GMR responses while maintaining thermostability.
    Type: Grant
    Filed: April 25, 2000
    Date of Patent: April 29, 2003
    Assignee: Seagate Technology LLC
    Inventors: Sining Mao, Zheng Gao, Jian Chen, Edward Stephens Murdock
  • Patent number: 6552881
    Abstract: A nonmagnetic conductive layer is provided on top of a free layer structure for at least counterbalancing sense current fields from conductive layers below the free layer structure so as to improve readback asymmetry of the spin valve sensor. Further, a magnetic conductive layer is provided on top of the nonmagnetic conductive layer for at least partially counterbalancing a demagnetizing field emanating from a pinned layer structure below the free layer structure. The nonmagnetic conductive layer, which is preferably copper (Cu), isolates the magnetization of the magnetic conductive layer from the free layer structure and also improves the soft magnetic properties of the free layer structure.
    Type: Grant
    Filed: May 17, 2000
    Date of Patent: April 22, 2003
    Assignee: International Business Machines Corporation
    Inventor: Mustafa Pinarbasi
  • Patent number: 6548114
    Abstract: A method of fabricating a spin valve sensor includes sequentially depositing, without breaking vacuum, a seed layer and an antiferromagnetic layer. Sequentially depositing the seed layer and the antiferromagnetic layer includes depositing a seed layer on a substrate; depositing a Mn-alloy layer of the antiferromagnetic layer directly on top of the seed layer; and depositing a buffer layer of the antiferromagnetic layer directly on top of the Mn-alloy layer. The seed layer, the Mn-alloy layer and the buffer layer are annealed. After annealing, a portion of the buffer layer is etched and a synthetic antiferromagnetic layer is deposited on top of the buffer layer. A spacer layer is deposited on top of the synthetic antiferromagnetic layer, and a free layer is deposited on top of the spacer layer.
    Type: Grant
    Filed: July 17, 2001
    Date of Patent: April 15, 2003
    Assignee: Seagate Technology LLC
    Inventors: Sining Mao, Anthony M. Mack, Brenda A. Everitt, Edward S. Murdock, Zheng Gao
  • Patent number: 6545848
    Abstract: A magnetic transducer and a thin film magnetic head capable of suppressing a reduction in reproducing output and of obtaining an appropriate bias magnetic field and a method of manufacturing the same. An MR element comprises a stack sensing an external magnetic field and magnetic domain control films applying a bias magnetic field to the stack. The magnetic domain control films are fabricated with a stack of magnetic domain control ferromagnetic films made of a ferromagnetic material and magnetic domain control antiferromagnetic films made of an antiferromagnetic material. The magnetic domain control ferromagnetic films are fabricated to have the magnetostriction &lgr;s within a range of −15×10−6<&lgr;s<0. The magnetostriction &lgr;s in such a range suppresses increase in hysteresis in a change of the magnetization of the magnetic domain control ferromagnetic film to an external magnetic field.
    Type: Grant
    Filed: June 23, 2000
    Date of Patent: April 8, 2003
    Assignee: TDK Corporation
    Inventor: Koichi Terunuma
  • Patent number: 6545847
    Abstract: A 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 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 respectively arranged at the ends 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: December 19, 2001
    Date of Patent: April 8, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhiro Nakamoto, Yoshiaki Kawato
  • Publication number: 20030058585
    Abstract: A thin film magnetic head has a reading element including a magnetoresistive effective film, a pair of magnetic domain-controlling films and a pair of electrode films. The magnetic domain-controlling films are provided both sides of the magnetoresistive effective film in a track width direction, respectively, so that the depth of the magnetic domain-controlling films is set equal to the depth of the magnetoresistive effective film in a depth direction perpendicular to the track width direction. The electrode films are provided on the magnetic domain-controlling films so as to have elongated portions, respectively, beyond a region where the depth of the magnetic domain-controlling films is set equal to the depth of the magnetoresistive effective film.
    Type: Application
    Filed: July 10, 2002
    Publication date: March 27, 2003
    Applicant: TDK Corporation
    Inventor: Shigeru Shoji
  • Publication number: 20030053267
    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: Application
    Filed: September 17, 2001
    Publication date: March 20, 2003
    Applicant: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Kochan Ju, Mao-Min Chen, Min Li, Ru-Ying Tong, Simon Liao
  • Publication number: 20030053268
    Abstract: Disclosed is a system and method for forming a current-perpendicular-to-plane (CPP) spin-valve sensor with one or more metallic oxide barrier layers in order to provide a low junction resistance and a high GMR coefficient. In disclosed embodiments, the metallic oxide barrier layers are formed with oxygen-doping/in-situ oxidation processes comprising depositing a metallic film in a first mixture of argon and oxygen gases and subsequent in-situ oxidization in a second mixture of argon and oxygen gases. The exposure to oxygen may be conducted at a low partial oxygen pressure and at a moderate temperature. Smaller, more sensitive CPP spin-valve sensors may be formed through the use of the oxygen-doping/in-situ oxidization processes of the present invention, thus allowing for greater densities of disk drive systems.
    Type: Application
    Filed: September 20, 2001
    Publication date: March 20, 2003
    Inventors: Tsann Lin, Daniele Mauri
  • Publication number: 20030053266
    Abstract: Nano-oxide based current-perpendicular-to-plane (CPP) magnetoresistive (MR) sensor stacks are provided, together with methods for forming such stacks. Such stacks have increased resistance and enhanced magnetoresistive properties relative to CPP stacks made entirely of metallic layers. Said enhanced properties are provided by the insertion of magnetic nano-oxide layers between ferromagnetic layers and non-magnetic spacer layers, whereby said nano-oxide layers increase resistance and exhibit spin filtering properties. CPP sensor stacks of various types are provided, all having nano-oxide layers formed therein, including the spin-valve type and the synthetic antiferromagnetic pinned layer spin-valve type. Said stacks can also be formed upon each other to provide laminated stacks of different types.
    Type: Application
    Filed: September 17, 2001
    Publication date: March 20, 2003
    Applicant: Headway Technologies, Inc.
    Inventors: Bernard Dieny, Cheng Horng, Kochan Ju, Min Li, Simon Liao
  • Publication number: 20030053269
    Abstract: A magnetic sensing element includes a composite film, a lower shield layer, and a lower electrode layer and an upper electrode layer for supplying a current perpendicular to the composite film. The composite film has an antiferromagnetic layer, a pinned magnetic layer, a nonmagnetic layer, and a free magnetic layer. The composite film has a top face and two side faces in a track width direction. Each of the two side faces has a bent position. The angle defined by the side face below the bent position and the top face is larger than the angle defined by the side face above the bent position and the top face. The bent portion preferably lies on the lower electrode layer or the lower shield layer.
    Type: Application
    Filed: September 11, 2002
    Publication date: March 20, 2003
    Applicant: Alps Electric Co., Ltd.
    Inventor: Yoshihiro Nishiyama
  • Patent number: 6535363
    Abstract: A thin-film magnetic head in which has a spin-valve element and a pair of electrode layers that are electrically connected to both ends of the element in the direction of width. A tantalum film is laminated as a protective layer on the uppermost part of the abovementioned element. A pair of electrode layers are caused to overlap on both end portions of the element. The tantalum oxide present in the areas on which the electrode layers overlap is removed prior to the formation of the electrode layers so that the electrical resistance between the electrode layers and the element is reduced.
    Type: Grant
    Filed: January 13, 2000
    Date of Patent: March 18, 2003
    Assignee: Read-Rite SMI Corporation
    Inventors: Masataka Hosomi, Tatsuo Sawasaki, Kouichi Matsuhashi
  • Patent number: 6535362
    Abstract: The magnetoresistive device of the present invention includes: at least two magnetic layers stacked via a non-magnetic layer therebetween; and a metal reflective layer of conduction electrons formed so as to be in contact with at least one of outermost two layers of the magnetic layers. The metal reflective layer is in contact with one surface of the outermost magnetic layer which is opposite to the other surface of the outermost magnetic layer in contact with the non-magnetic layer. The metal reflective layer is likely to reflect conduction electrons while maintaining a spin direction of electrons.
    Type: Grant
    Filed: November 26, 1997
    Date of Patent: March 18, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Yasuhiro Kawawake, Hiroshi Sakakima, Mitsuo Satomi
  • Publication number: 20030039080
    Abstract: A magneto-resistive device has a magneto-resistive layer laminated between electrodes. The magneto-resistive layer has a non-magnetic layer, a pinned layer and a free layer sandwiching the non-magnetic layer, and a pin layer formed on the pinned layer on the opposite side to the free layer. The pin layer is formed in a region which substantially overlaps with an effective region in a film plane direction in which a current flows in a direction substantially perpendicular to the film plane between the electrodes in a predetermined thickness, and is formed in a region which does not substantially overlap with the effective region substantially in the same thickness as the predetermined thickness or in a thickness smaller than the predetermined thickness, continuous from the region which substantially overlaps with the effective region.
    Type: Application
    Filed: August 5, 2002
    Publication date: February 27, 2003
    Applicant: TDK Corporation
    Inventors: Takeo Kagami, Norio Takahashi, Takumi Uesugi
  • Publication number: 20030039079
    Abstract: As the dimensions of spin valve heads continue to be reduced, a number of difficulties are being encountered. One such is with the longitudinal bias when an external magnetic field can cause reversal of the hard magnet, thereby causing a hysteric response by the head. This coercivity reduction becomes more severe as the hard magnet becomes thinner. This problem has been overcome by inserting a decoupling layer between the antiferromagnetic layer that is used to stabilize the pinned layer of the spin valve itself and the soft ferromagnetic layer that is used for longitudinal biasing. This soft ferromagnetic layer is pinned by a second antiferromagnetic layer deposited on it on its far side away from the first antiferromagnetic layer. The presence of the decoupling layer ensures that the magnetization of the soft layer is determined only by the second antiferromagnetic layer. The inclusion of said decoupling layer allows more latitude in etch depth control during manufacturing.
    Type: Application
    Filed: August 22, 2001
    Publication date: February 27, 2003
    Applicant: Headway Technologies, Inc.
    Inventors: You Feng Zheng, Kochan Ju, Cheng T. Horng, Simon Liao, Ru Ying Tong
  • Publication number: 20030035254
    Abstract: A magnetic head using magneto-resistive effect includes a spin-valve type giantmagneto-resistive effect element or tunnel-typemagneto-resistive effect element type lamination layer structure portion in which a free layer 4 made of a soft magnetic material of which the magnetization is rotated in response to an external magnetic field, a fixed layer 6 made of a ferromagnetic material, an antiferromagnetic layer 7 for fixing the magnetization of this fixed layer 6 and a spacer layer 5, i.e., nonmagnetic conductive layer or a tunnel barrier layer are laminated with each other.
    Type: Application
    Filed: August 14, 2002
    Publication date: February 20, 2003
    Inventors: Akio Furukawa, Yoshihiko Kakihara
  • Publication number: 20030035250
    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: Application
    Filed: August 17, 2001
    Publication date: February 20, 2003
    Applicant: Headway Technologies, Inc.
    Inventors: Kochan Ju, You Feng Zheng, Rod Lee
  • Publication number: 20030030944
    Abstract: Disclosed is a spin-valve sensor employing one or more in-situ oxidized films as cap and/or gap layers in order to achieve an increased GMR coefficient and improved thermal stability. A fabrication method comprises depositing multilayer metallic films on a wafer in ion-beam and DC-magnetron sputtering modules of a sputtering system, and then transferring the wafer in a vacuum to an oxidation module where in-situ oxidation is conducted. When the method is used to form a cap layer, the cap layer may only be partially oxidized. A magnetic-field annealing may be subsequently conducted without the substantial occurrence of interface mixing and oxygen diffusion during the anneal process. The resulting spin-valve sensor exhibits an increased GMR coefficient, possibly due to induced specular scattering of conduction electrons and improved thermal stability mainly due to the protection of an underlying sensing layer from interface mixing and oxygen diffusion during the annealing process.
    Type: Application
    Filed: July 31, 2001
    Publication date: February 13, 2003
    Inventors: Tsann Lin, Daniele Mauri
  • Publication number: 20030030434
    Abstract: A seed layer is formed with a Cr layer in which the direction of a crystal face in at least one crystal grain is oriented in a different direction from the direction of an equivalent crystal face in another crystal grain. Consequently, wettability of the seed layer can be markedly improved and the unidirectional exchange bias magnetic field in a pinned magnetic layer can be increased while permitting the surface of each layer on the seed layer to have good lubricity.
    Type: Application
    Filed: July 17, 2002
    Publication date: February 13, 2003
    Applicant: Alps Electric Co., Ltd.
    Inventors: Naoya Hasegawa, Masamichi Saito, Kenichi Tanaka
  • Patent number: 6519120
    Abstract: An SV sensor with the preferred structure Substrate/Seed/Free/Spacer/Pinned/AFM/Cap where the seed layer is a non-magnetic Ni—Fe—Cr or Ni—Cr film and the AFM layer is preferably Ni—Mn. The non-magnetic Ni—Fe—Cr seed layer results in improved grain structure in the deposited layers enhancing the GMR coefficients and the thermal stability of the SV sensors. The improved thermal stability enables use of Ni—Mn with its high blocking temperature and strong pinning field as the AFM layer material without SV sensor performance degradation from the high temperature anneal step needed to develop the desired exchange coupling.
    Type: Grant
    Filed: August 2, 2000
    Date of Patent: February 11, 2003
    Assignee: International Business Machines Corporation
    Inventors: Wen Yaung Lee, Tsann Lin, Daniele Mauri, Robert John Wilson
  • Publication number: 20030026047
    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: July 30, 2001
    Publication date: February 6, 2003
    Applicant: Headway Technologies, Inc.
    Inventors: Chen-Jung Chien, Chyu-Jiuh Torng, Cherng-Chyi Han, Moris Dovek, Po-Kang Wang, Mao-Min Chen
  • Publication number: 20030021071
    Abstract: A spin valve sensor system and method for fabricating the same is provided. Included is a free layer and a pinned layer with a spacer layer disposed between the free layer and the pinned layer. Such spacer layer is oxidized for improving operational characteristics of the spin valve sensor.
    Type: Application
    Filed: April 30, 2001
    Publication date: January 30, 2003
    Inventors: Witold Kula, Alexander Zeltser
  • Patent number: 6512660
    Abstract: A current perpendicular-to-the-plane magnetoresistance (CPP-MR) read head includes a top shield, a bottom shield, and a giant magnetoresistance structure. Top and bottom shields are formed of magnetically shielding, electrically conductive material. The GMR structure is disposed between the top shield and the bottom shield with the GMR structure being in electrical contact with the top and bottom shield such that a sense current flows from one of the top and bottom shields through the GMR structure to the other one of the top and bottom shields. A metal pillar is electrically connected to one of the top and bottom shields. The metal pillar carries the sense current and is disposed such that the current flows in a direction generally perpendicular-to-the-plane of the GMR structure. Depending on the particular application, the read head can be configured so that current flowing in the metal pillar provides either a longitudinal or a transverse bias to the giant magnetoresistance structure.
    Type: Grant
    Filed: October 17, 2000
    Date of Patent: January 28, 2003
    Assignee: TDK Corporation
    Inventors: Shuxiang Li, Satoru Araki
  • Publication number: 20030016475
    Abstract: No related magnetoresistive multi-layered films made from a metal magnetic film provide sufficient reproducing output power. A high-polarized layer with a thickness of 10 nm or less is formed as a Fe-rich Fe—O layer in contact with the interface of a non-magnetic intermediate layer and the resulting layers are heat treated to form a multi-layered film of ferromagnetic Fe—O layers, achieving a magnetoresistive element having high magnetoresistance.
    Type: Application
    Filed: July 15, 2002
    Publication date: January 23, 2003
    Applicant: Hitachi. Ltd.
    Inventors: Hiroyuki Hoshiya, Susumu Soeya, Kenichi Meguro