Detail Of Pinned Film Or Additional Film For Affecting Or Biasing The Pinned Film Patents (Class 360/324.11)
  • Patent number: 7606009
    Abstract: A read sensor stabilized by bidirectional anisotropy is disclosed. The read sensor includes a longitudinal flux-closure structure comprising an antiferromagnetic pinning layer, a ferromagnetic bias layer, a nonmagnetic spacer layer, and a ferromagnetic sense layer. In this longitudinal flux-closure structure, the antiferromagnetic pinning layer directly couples to the ferromagnetic bias layer inducing strong unidirectional anisotropy, and also indirectly couples to the ferromagnetic sense layer inducing weak unidirectional anisotropy. In addition, the ferromagnetic bias layer antiparallel-couples to the ferromagnetic sense layer across the nonmagnetic spacer layer inducing optimal bidirectional anisotropy. The magnetization of the ferromagnetic bias layer thus remains rigidly pinned mainly due to the strong unidirectional anisotropy, while the magnetization of the ferromagnetic sense layer can rotate freely and stably due to the optimal bidirectional anisotropy.
    Type: Grant
    Filed: March 15, 2006
    Date of Patent: October 20, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Tsann Lin
  • Publication number: 20090257152
    Abstract: A magnetoresistive sensor having an antiparallel coupled pinned layer structure including an AP1 layer and an AP2 layer. The AP2 layer includes two ferromagnetic layers AP2(a) and AP2(b), and a separation layer sandwiched therebetween. The AP2(a) layer is significantly larger than the AP2(b) layer, which results in strong pinning, while the separation layer provides increased TMR and reduced RA.
    Type: Application
    Filed: December 30, 2008
    Publication date: October 15, 2009
    Inventors: Wen-yaung Lee, Chang Man Park, Brian R. York, Alexander M. Zeltser
  • Patent number: 7602589
    Abstract: A magnetoresistive sensor having a pinned layer that extends beyond the free layer in the stripe height direction for improved shape enhanced pinning. The sensor includes hard bias layers and leads that extend in the stripe height direction beyond the stripe height of the free layer, providing increased conductive material for improved conduction of sense current to the sensor. The hard bias layers contact the sensor stack in the region between the ABS and the stripe height of the free layer, but are electrically insulated from the pinned layer in regions beyond the stripe height of the free layer by a layer of conformally deposited non-magnetic, electrically insulating material such as alumina.
    Type: Grant
    Filed: August 30, 2006
    Date of Patent: October 13, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Patent number: 7599157
    Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has a high-resistivity amorphous ferromagnetic alloy in the free layer and/or the pinned layer. The sensor may have an antiparallel (AP)-pinned structure, in which case the AP2 layer may be formed of the high-resistivity amorphous ferromagnetic alloy. The amorphous alloy is an alloy of one or more elements selected from Co, Fe and Ni, and at least one nonmagnetic element X. The additive element or elements is present in an amount that renders the otherwise crystalline alloy amorphous and thus substantially increases the electrical resistivity of the layer. As a result the resistance of the active region of the sensor is increased. The amount of additive element or elements is chosen to be sufficient to render the alloy amorphous but not high enough to substantially reduce the magnetic moment M or bulk electron scattering parameter ?.
    Type: Grant
    Filed: February 16, 2006
    Date of Patent: October 6, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
  • Patent number: 7599158
    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 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. A process for manufacturing the device is also described.
    Type: Grant
    Filed: March 12, 2007
    Date of Patent: October 6, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Po Kang Wang, Moris Dovek, Jibin Geng, Tai Min
  • Patent number: 7599155
    Abstract: A CPP giant magnetoresistive head includes lower and upper shield layers, and a giant magnetoresistive element disposed between the upper and lower shield layers and including a pinned magnetic layer, a free magnetic layer and a nonmagnetic layer disposed between the pinned magnetic layer and the free magnetic layer. In the CPP giant magnetoresistive head, the pinned magnetic layer extends to the rear of the nonmagnetic layer and the free magnetic layer in the height direction, and the dimension of the pinned magnetic layer in the height direction is larger than that in the track width direction. Also, the pinned magnetic layer comprises a magnetic material having a positive magnetostriction constant or a magnetic material having high coercive force, and the end of the pinned magnetic layer is exposed at a surface facing a recording medium.
    Type: Grant
    Filed: April 13, 2004
    Date of Patent: October 6, 2009
    Assignee: TDK Corporation
    Inventors: Masamichi Saito, Yoshihiro Nishiyama, Yosuke Ide, Eiji Umetsu, Naoya Hasegawa, Yasuo Hayakawa
  • Patent number: 7599156
    Abstract: A magnetoresistive element according to an example of the present invention has a stacked structure comprised first and second ferromagnetic layers and a nonmagnetic layer disposed between these ferromagnetic layers, and a planar shape of at least one of the first and second ferromagnetic layers has a shape formed by combining two or more parts each having a shape of a character C.
    Type: Grant
    Filed: October 6, 2005
    Date of Patent: October 6, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Tatsuya Kishi, Masahiko Nakayama, Yoshiaki Fukuzumi, Tadashi Kai
  • Patent number: 7599154
    Abstract: A magnetoresistive read head includes a spin valve having a multi-layer in-stack bias and side shields to substantially reduce the undesired flux from adjacent bits and tracks, as well as from the transverse field of the recording medium itself. At least one free layer is spaced apart from at least one pinned layer by a spacer. Above the free layer, a capping layer is provided, followed by the in-stack bias, which includes a non-magnetic conductive layer, a ferromagnetic layer having a magnetization fixed by an anti-ferromagnetic layer, and a stabilizing ferromagnetic layer. Additionally, a multilayered side shield is provided, including a thin insulator, a soft buffer layer and a soft side shield layer. As a result, the free layer is shielded from the undesired flux, and recording media having substantially smaller track size and bit size.
    Type: Grant
    Filed: April 2, 2004
    Date of Patent: October 6, 2009
    Assignee: TDK Corporation
    Inventors: Rachid Sbiaa, Isamu Sato
  • Publication number: 20090244792
    Abstract: A magnetoresistance effect element includes: a first ferromagnetic layer having invariable magnetization perpendicular to a film plane; a second ferromagnetic layer having variable magnetization perpendicular to the film plane; a first nonmagnetic layer interposed between the first ferromagnetic layer and the second ferromagnetic layer; a third ferromagnetic layer provided on an opposite side of the second ferromagnetic layer from the first nonmagnetic layer, and having variable magnetization parallel to the film plane; and a second nonmagnetic layer interposed between the second and third ferromagnetic layers.
    Type: Application
    Filed: March 3, 2009
    Publication date: October 1, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masahiko NAKAYAMA, Tadashi KAI, Sumio IKEGAWA, Hiroaki YODA, Tatsuya KISHI
  • Patent number: 7593196
    Abstract: A method and apparatus for providing a magnetic read sensor having a thin pinning layer and improved magnetoresistive coefficient ?R/R is disclosed. A thin IrMn alloy pinning layer is disposed adjacent a composite pinned layer, wherein the percentage of iron in the pinned layer adjacent the thin IrMn alloy pinning layer in the range of 20-40% to provide maximum pinning and the thicknesses of the outer ferromagnetic layers should be comparable.
    Type: Grant
    Filed: April 30, 2004
    Date of Patent: September 22, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7583481
    Abstract: A CPP-GMR spin valve having a pinned layer with an AP2/coupling/AP1 configuration is disclosed wherein the AP2 portion is a FCC-like trilayer having a composition represented by CoZFe(100-Z)/Fe(100-X)TaX/CoZFe(100-Z) or CoZFe(100-Z)/FeYCo(100-Y)/CoZFe(100-Z) where x is 3 to 30 atomic %, y is 40 to 100 atomic %, and z is 75 to 100 atomic %. Preferably, z is 90 to provide a face centered cubic structure that minimizes electromigration. Optionally, the middle layer is comprised of an Fe rich alloy such as FeCr, FeV, FeW, FeZr, FeNb, FeHf, or FeMo. EM performance is improved significantly compared to a spin valve with a conventional AP2 Co50Fe5 or Co75Fe25 single layer. The MR ratio of the spin valve is also increased and the RA is maintained at an acceptable level. The coupling layer is preferably Ru and the AP1 layer may be comprised of a lamination of CoFe and Cu layers as in [CoFe/Cu]2/CoFe.
    Type: Grant
    Filed: September 23, 2005
    Date of Patent: September 1, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Dan Abels, Min Li, Chyu-Jiuh Torng, Chen-Jung Chien, Yu-Hsia Chen
  • Patent number: 7580230
    Abstract: A magnetoresistive sensor having a shape enhanced pinning and a flux guide structure. First and second hard bias layers and lead layers extend from the sides of a sensor stack. The hard bias layers and leads have a stripe height that is smaller than the stripe height of a free layer, resulting in a free layer that extends beyond the back edge of the lead and hard bias layer. This portion of the free layer that extends beyond the back edge of the leads and hard bias layers provides a back flux guide. Similarly, the sensor may have a free layer that extends beyond the front edge of the lead and hard bias layers to provide a front flux guide. The pinned layer extends significantly beyond the back edge of the free layer, providing the pinned layer with a strong shape enhanced magnetic anisotropy.
    Type: Grant
    Filed: October 24, 2006
    Date of Patent: August 25, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Publication number: 20090207534
    Abstract: A magneto-resistance effect element comprises; a magneto-resistance effect stack including an upper magnetic layer and a lower magnetic layer in which respective magnetization directions change in accordance with an external magnetic field, a non-magnetic intermediate layer sandwiched between the upper and lower magnetic layers, an upper gap adjustment layer and a lower gap adjustment layer provided at respective ends in the direction of stacking the magneto-resistance effect stack, an upper exchange coupling transmission layer configured to generate exchange coupling between the upper magnetic layer and the upper gap adjustment layer, and a lower exchange coupling transmission layer configured to generate exchange coupling between the lower magnetic layer and the lower gap adjustment layer; an upper shield electrode layer and a lower shield electrode layer which are provided to sandwich the magneto-resistance effect stack therebetween in the direction of stacking the magneto-resistance effect stack, wherein
    Type: Application
    Filed: February 19, 2008
    Publication date: August 20, 2009
    Applicant: TDK Corporation
    Inventors: Daisuke MIYAUCHI, Koji SHIMAZAWA, Tsutomu CHOU, Takahiko MACHITA
  • Publication number: 20090201614
    Abstract: It is made possible to to provide a spin-torque oscillator that has a high Q value and a high output. A spin-torque oscillator includes: an oscillating field generating unit configured to generate an oscillating field; and a magnetoresistive element including a magnetoresistive effect film including a first magnetization pinned layer of which a magnetization direction is pinned, a first magnetization free layer of which a magnetization direction oscillates with the oscillating field, and a first spacer layer interposed between the first magnetization pinned layer and the first magnetization free layer.
    Type: Application
    Filed: September 29, 2008
    Publication date: August 13, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Kiwamu Kudo, Tazumi Nagasawa, Koichi Mizushima, Rie Sato
  • Publication number: 20090190262
    Abstract: A magnetoresistive element includes a magnetoresistive film including a magnetization pinned layer, a magnetization free layer, an intermediate layer arranged between the magnetization pinned layer and the magnetization free layer, a cap layer arranged on the magnetization pinned layer or on the magnetization free layer, and a functional layer formed of an oxygen- or nitrogen-containing material and arranged in the magnetization pinned layer, or in the magnetization free layer, and a pair of electrodes which pass a current perpendicularly to a plane of the magnetoresistive film, in which a crystalline orientation plane of the functional layer is different from a crystalline orientation plane of its upper or lower adjacent layer.
    Type: Application
    Filed: January 30, 2009
    Publication date: July 30, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Shuichi Murakami, Hideaki Fukuzawa, Hiromi Yuasa, Yoshihiko Fuji
  • Patent number: 7565733
    Abstract: An improved method for the manufacture of magnetoresistive multilayer sensors is disclosed. The method is particularly advantageous for the production of magnetic tunnel junction (MTJ) sensors, which can be damaged at the air bearing surface by conventional lapping and ion milling. The disclosed process protects the ABS of the magnetoresistive sensor by depositing a diamond like carbon layer which remains in place through ion milling. The DLC layer is removed by oxidation subsequent to the formation of the ABS.
    Type: Grant
    Filed: May 16, 2006
    Date of Patent: July 28, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hardayal Singh Gill, Wipul Pemsiri Jayasekara, Huey-Ming Tzeng, Xiao Z. Wu
  • Patent number: 7567413
    Abstract: There is provided a magnetic detecting element by devising a configuration of a free magnetic layer or a pinned magnetic layer, and a method of manufacturing a magnetic detecting element. The free magnetic layer is formed to have a three-layered structure of a CoMnZ alloy layer, a CoMnX alloy layer, and a CoMnZ alloy layer. The CoMnX alloy layer is formed of a metal compound whose compositional formula is represented by CoaMnbXc (X is one or more elements selected from a group of Ge, Sn, Ga, and Sb, a, b, and c are atomic percent, and a+b+c=100 atomic percent). The CoMnZ alloy layer is formed of a metal compound whose compositional formula is represented by CodMneZf (Z is Al or Si, d, e, and f are atomic percent, and d+e+f=100 atomic percent).
    Type: Grant
    Filed: April 3, 2006
    Date of Patent: July 28, 2009
    Assignee: TDK Corporation
    Inventors: Yosuke Ide, Masamichi Saito, Masahiko Ishizone, Naoya Hasegawa
  • Patent number: 7567411
    Abstract: A magnetoresistive sensor includes first and second magnetic leads and a constricted junction joining the first and second magnetic leads. The first and second magnetic leads are formed of a magnetic and electrically conductive material. The constricted junction includes a junction core formed of magnetic and electrically conductive material. In one embodiment, the constricted junction also includes an ion implanted outer shell portion that at least partially surrounds the junction core and has reduced magnetic and electrical conductivity relative to the junction core. In another embodiment, the junction core has a length that is defined by a distance separating the first and second magnetic leads, and a width that is perpendicular to the length and is substantially less than an average unrestricted magnetic domain wall width corresponding to the magnetic material of the junction core.
    Type: Grant
    Filed: December 14, 2006
    Date of Patent: July 28, 2009
    Assignee: Seagate Technology LLC
    Inventors: Ge Yi, Suguo Huo
  • Patent number: 7564660
    Abstract: A method for forming a bottom spin valve sensor element with a novel seed layer and synthetic antiferromagnetic pinned layer and the sensor so formed. The novel seed layer comprises an approximately 30 angstrom thick layer of NiCr whose atomic percent of Cr is 31%. On this seed layer there can be formed either a single bottom spin valve read sensor or a symmetric dual spin valve read sensor having synthetic antiferromagnetic pinned layers. An extremely thin (approximately 80 angstroms) MnPt pinning layer can be formed directly on the seed layer and extremely thin pinned and free layers can then subsequently be formed 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: Grant
    Filed: May 17, 2007
    Date of Patent: July 21, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Hui-Chuan Wang, Ru-Ying Tong, Chyu-Jiuh Trong
  • Patent number: 7564658
    Abstract: A GMR spin value structure with improved performance and a method for making the same is disclosed. A key feature is the incorporation of a thin ferromagnetic insertion layer such as a 5 Angstrom thick CoFe layer between a NiCr seed layer and an IrMn AFM layer. Lowering the Ar flow rate to 10 sccm for the NiCr sputter deposition and raising the Ar flow rate to 100 sccm for the IrMn deposition enables the seed layer to be thinned to 25 Angstroms and the AFM layer to about 40 Angstroms. As a result, HEX between the AFM and pinned layers increases by up to 200 Oe while the Tb is maintained at or above 250° C. When the seed/CoFe/AFM configuration is used in a read head sensor, a higher GMR ratio is observed in addition to smaller free layer coercivity (HCF), interlayer coupling (HE), and HK values.
    Type: Grant
    Filed: September 23, 2004
    Date of Patent: July 21, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Tong Zhao, Min Li, Chyu-Jiuh Torng
  • Patent number: 7564659
    Abstract: A magnetoresistive sensor having a magnetically anisotropic pinned layer structure. The pinned layer structure is formed over a seed layer having a surface that has been treated to texture the surface of the seed layer with an anisotropic roughness. This anisotropic roughness induces the magnetic anisotropy in the pinned layers. The treated seed layers also allow the pinned layer to maintain robust pinning without the need for a thick AFM layer, thereby reducing gap size.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: July 21, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Mustafa Michael Pinarbasi
  • Publication number: 20090168270
    Abstract: In comparison with conventional exchange-coupled elements, the exchange-coupled element of the present invention has greater unidirectional magnetization anisotropy. The exchange-coupled element comprises: an ordered antiferromagnetic layer; and a pinned magnetic layer being exchange-coupled with the ordered antiferromagnetic layer, the pinned magnetic layer having unidirectional magnetization anisotropy. The pinned magnetic layer is constituted by a first pinned magnetic layer having a composition, which can have a face-centered cubic lattice structure, and a second pinned magnetic layer having a composition, which can have a body-centered cubic lattice structure.
    Type: Application
    Filed: December 23, 2008
    Publication date: July 2, 2009
    Applicants: FUJITSU LIMITED, TOHOKU UNIVERSITY
    Inventors: Migaku Takahashi, Masakiyo Tsunoda, Koujiro Komagaki, Yuji Uehara
  • Publication number: 20090168269
    Abstract: A current perpendicular to plane magnetoresistive sensor having improved resistance amplitude change and reduced spin torque noise. The sensor has an antiparallel coupled pinned layer structure with at least one of the layers of the pinned layer structure includes a high spin polarization material such as Co2FeGe. The sensor can also include an antiparallel coupled free layer.
    Type: Application
    Filed: December 28, 2007
    Publication date: July 2, 2009
    Inventors: Matthew Joseph Carey, Jeffrey Robinson Childress, Stefan Maat, Neil Smith
  • Patent number: 7554775
    Abstract: A giant magnetoresistance (GMR) sensor with strongly pinning and pinned layers is described for magnetic recording at ultrahigh densities. The pinning layer is an antiferromagnetic (AFM) iridium-manganese-chromium (Ir—Mn—Cr) film having a Mn content of approximately from 70 to 80 atomic percent and having a Cr content of approximately from 1 to 10 atomic percent. The first pinned layer is preferably a ferromagnetic Co—Fe having an Fe content of approximately from 20 to 80 at % and having high, positive saturation magnetostriction. The second pinned layer is preferably a ferromagnetic Co—Fe having an Fe content of approximately from 0 to 10 atomic percent. The net magnetic moment of the first and second pinned layers is designed to be nearly zero in order to achieve a pinning field of beyond 3,000 Oe.
    Type: Grant
    Filed: February 28, 2005
    Date of Patent: June 30, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Jinshan Li, Tsann Lin
  • Patent number: 7554776
    Abstract: A CPP magnetic sensing element is provided which may exhibit a large value of ?RA (the product of the resistance variation ?R and area A of the magnetic sensing element). The magnetic sensing element includes a free magnetic layer and a pinned magnetic layer. At least one of these layers has a (Co0.67Fe0.33)100-aZa alloy layer, wherein Z may represent at least one element selected from the group consisting of Al, Ga, Si, Ge, Sn, and Sb, and the parameter a may satisfy the relationship 0<a?30 in terms of atomic percent.
    Type: Grant
    Filed: August 29, 2005
    Date of Patent: June 30, 2009
    Assignee: TDK Corporation
    Inventors: Naoya Hasegawa, Masamichi Saito, Yosuke Ide, Masahiko Ishizone
  • Publication number: 20090161268
    Abstract: A method, apparatus, and article of manufacture for a current-perpendicular-to-plane (CPP) giant magnetoresistance (GMR) or a tunneling magnetoresistance (TMR) read sensor is proposed. The CPP read sensor comprises an amorphous ferromagnetic first seed layer, a polycrystalline nonmagnetic second seed layer, a nonmagnetic first cap layer, a nonmagnetic second cap layer, and a ferromagnetic third gap layer. A read gap is defined by a distance between the ferromagnetic first seed layer and the ferromagnetic third cap layer.
    Type: Application
    Filed: December 22, 2007
    Publication date: June 25, 2009
    Inventor: Tsann Lin
  • Patent number: 7551408
    Abstract: Both end portions of a magneto-resistive effect film form a junction taper shape and, at both end portions forming the junction taper shape, a pair of bias magnetic field applying layers are disposed via underlayers for applying a longitudinal bias magnetic field to a soft magnetic layer. Each of the underlayers is formed by a thin film made of at least one element selected from a group of Ru, Ti, Zr, Hf, and Zn or an alloy thin film containing, as a main component, at least one element selected from the group. Each of the bias magnetic field applying layers formed on the underlayers is formed by a hard magnetic layer and has a thickness of 200 ? or less (not including zero).
    Type: Grant
    Filed: April 12, 2005
    Date of Patent: June 23, 2009
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Kosuke Tanaka, Tomoaki Shimizu
  • Patent number: 7542247
    Abstract: A magnetic disk apparatus having a highly sensitive reproducing head and a method for manufacturing the magnetic disk apparatus are disclosed. A spin-valve-type multilayer film composed of an antiferromagnetic layer, a ferromagnetic layer, a nonmagnetic layer and a free magnetic layer is used as a magnetoresistive-effect device for the reproducing head. An antiferromagnetic reaction layer is formed between the antiferromagnetic reaction layer and the ferromagnetic layer. The antiferromagnetic reaction layer is formed of a metallic compound containing oxygen.
    Type: Grant
    Filed: October 30, 2007
    Date of Patent: June 2, 2009
    Assignee: Panasonic Corporation
    Inventor: Akifumi Aono
  • Patent number: 7542248
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, if a pinned layer and a free layer have a stacked construction of a magnetic layer and a non-magnetic layer or a stacked construction of a magnetic layer and a magnetic layer, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Grant
    Filed: November 23, 2007
    Date of Patent: June 2, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuzo Kamiguchi, Hiromi Yuasa, Tomohiko Nagata, Hiroaki Yoda
  • Patent number: 7536772
    Abstract: A method is given for the manufacture of a bottom spin valve (BSV) spin filter spin valve (SFSV) type read sensor. The sensor has a composite, ultra-thin (<20 Angstroms) laminated free layer formed as a Cu high conductance layer (HCL) between two layers of CoFe. A second HCL is formed as a layer of Ru on the composite free layer. By adjusting the thicknesses of the two HCL's, the free layer will have low coercivity and tunable magnetostriction. The sensor is capable of reading densities exceeding 60 Gb/in2.
    Type: Grant
    Filed: November 8, 2005
    Date of Patent: May 26, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 7538988
    Abstract: A method and apparatus for an improved magnetic read sensor having synthetic or AP pinned layers with high resistance and high magnetoelastic anisotropy is disclosed. A pinned layer includes a cobalt-iron ternary alloy, where a third constituent of the cobalt-iron ternary alloy layer is selected for increasing the resistance and magnetoelastic anisotropy of the cobalt-iron ternary alloy layer.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: May 26, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Jinshan Li, Alexander M. Zeltser
  • Patent number: 7533456
    Abstract: A free layer functions such that a magnetization direction changes depending on an external magnetic field, and is made up of a multilayer structure including a first Heusler alloy layer, and a fixed magnetization layer takes a form wherein an inner pin layer and an outer pin layer are stacked one upon another with a nonmagnetic intermediated layer sandwiched between them. The inner pin layer is made up of a multilayer structure including a second Heusler alloy layer. The first and second Heusler alloy layers are each formed by a co-sputtering technique using a split target split into at least two sub-targets in such a way as to constitute a Heusler alloy layer composition. When the Heusler alloy layer is formed, therefore, it is possible to bring up a film-deposition rate, improve productivity, and improve the performance of the device.
    Type: Grant
    Filed: June 1, 2007
    Date of Patent: May 19, 2009
    Assignee: TDK Corporation
    Inventors: Yoshihiro Tsuchiya, Tomohito Mizuno, Koji Shimazawa
  • Patent number: 7532442
    Abstract: Magnetoresistive (MR) elements having pinning layers formed from a permanent magnetic material are disclosed. An MR element of the invention includes a first pinning layer, a first pinned layer, a first spacer/barrier layer, a free layer, a second spacer/barrier layer, a second pinned layer, and a second pinning layer. One of the first pinning layer or the second pinning layer is formed from a permanent magnetic material, such as CoPt or CoPtCr. The other of the first pinning layer or the second pinning layer is formed from an antiferromagnetic (AFM) material, such as IrMn or PtMn.
    Type: Grant
    Filed: September 19, 2005
    Date of Patent: May 12, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal S. Gill
  • Patent number: 7530160
    Abstract: A method for manufacturing a magnetoresistive sensor having improved free layer biasing and track width control. The method includes forming a ferromagnetic pinned layer, and depositing a ferromagnetic film thereover. A layer of Ta is deposited over the ferromagnetic film and a mask is formed over an active sensor area. A reactive ion etch process is performed to remove selected portions of said Ta layer. An etch is then performed to remove selected portions of the ferromagnetic film in unmasked areas and a ferromagnetic refill material is deposited.
    Type: Grant
    Filed: September 5, 2007
    Date of Patent: May 12, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7529066
    Abstract: A magnetoresistive sensor having a magnetic anisotropy induced in one or both of the free layer and/or pinned layer. The magnetic anisotropy is induced by a surface texture formed in the surface of the magnetic layer of either or both of the free layer or pinned layer. The surface texture is formed by a direct, angled ion mill performed on the surface of the magnetic layer while holding the wafer on a stationary chuck. By applying this ion milling technique, the magnetic anisotropy of the pinned layer can be formed in a first direction (eg. perpendicular to the ABS) while the magnetic anisotropy of the free layer can be formed perpendicular to that of the pinned layer (eg. parallel to the ABS).
    Type: Grant
    Filed: December 14, 2005
    Date of Patent: May 5, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew Joseph Carey, Jeffrey Robinson Childress, Stefan Maat
  • Patent number: 7525776
    Abstract: A magnetoresistive element has a magnetization pinned layer a magnetization direction of which is substantially pinned in one direction, a magnetization free layer a magnetization direction of which varies depending on an external field, and a spacer layer including an insulating layer provided between the magnetization pinned layer and the magnetization free layer and current paths penetrating the insulating layer, the magnetization pinned layer or magnetization free layer located under the spacer layer comprising crystal grains separated by grain boundaries extending across a thickness thereof, in which, supposing that an in-plane position of one end of each of the crystal grains is set to 0 and an in-plane position of a grain boundary adjacent to the other end of the crystal grain is set to 100, the current path corresponding the crystal grain is formed on a region in a range between 20 and 80 of the in-plane position.
    Type: Grant
    Filed: November 9, 2005
    Date of Patent: April 28, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Katsuhiko Koui, Hitoshi Iwasaki
  • Patent number: 7524381
    Abstract: A method for controlling magnetostriction in a free layer of a magnetoresistive sensor. A pinned layer structure is deposited and then a spacer layer, preferably Cu is deposited. Oxygen is introduced into the spacer layer. The oxygen can be introduced either during the deposition of the spacer layer or after the spacer layer has been deposited. A free layer structure is then deposited over the spacer layer. A capping layer such as Ta can be deposited over the free layer structure. The sensor is annealed to set the magnetization of the pinned layer. In the process of annealing the sensor the oxygen migrates out of the spacer. After annealing, no significant amount of oxygen is present in either the spacer layer or the free layer structure, and only trace amounts of oxygen are present in the Ta capping layer.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: April 28, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ben Long Thai, Dulip Ajantha Welipitiya
  • Patent number: 7525774
    Abstract: A laser diode capable of being easily mounted and a laser diode device in which the laser diode is mounted are provided. A hole is disposed in a semiconductor layer, and a p-type electrode and an n-type semiconductor layer are electrically connected to each other by a bottom portion (a connecting portion) of the hole. Thereby, the p-type electrode has the same potential as the n-type semiconductor layer, and a saturable absorption region is formed in a region corresponding to a current path. Light generated in a gain region (not shown) is absorbed in the saturable absorption region so as to be converted into a current. The current is discharged to a ground via the p-side electrode and the bottom portion, an interaction between the saturable absorption region and the gain region is initiated, and thereby self-oscillation can be produced.
    Type: Grant
    Filed: September 19, 2005
    Date of Patent: April 28, 2009
    Assignee: Sony Corporation
    Inventors: Yutaka Soda, Masaaki Sekine
  • Patent number: 7525773
    Abstract: A thin film magnetic head includes a dual spin-valve magneto-resistive element. The dual spin-valve magneto-resistive element has a dual spin-valve magneto-resistive effect multilayer film composed of a first antiferromagnetic layer, a first fixed magnetic layer being a synthetic ferrimagnetic fixed layer, a first nonmagnetic layer, a soft magnetic layer, a second nonmagnetic layer, and a second fixed magnetic layer being a synthetic ferrimagnetic fixed layer. A stacked film thickness relationship of the first fixed magnetic layer, a stacked film thickness relationship of the second fixed magnetic layer, and a magnetostrictive constant are determined, and it is configured such that a static magnetic field produced from the first fixed magnetic layer and a current magnetic field generated by a sense current act to assist magnetization of the second fixed magnetic layer.
    Type: Grant
    Filed: April 14, 2005
    Date of Patent: April 28, 2009
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Yoshihiro Tsuchiya
  • Patent number: 7525775
    Abstract: A magnetoresistive sensor having improved pinning field strength. The sensor includes a pinned layer structure pinned by exchange coupling with an antiferromagnetic (AFM) layer. The AFM layer is constructed upon an under layer having treated surface with an anisotropic roughness. The anisotropic roughness, produced by an angled ion etch, results in improved pinning strength. The underlayer may include a seed layer and a thin layer of crystalline material such as PtMn formed over the seed layer. The magnetic layer may include a first sub-layer of NiFeCr and a second sub-layer of NiFe formed there over. The present invention also includes a magnetoresistive sensor having a magnetic layer deposited on an underlayer (such as a non-magnetic spacer) having a surface treated with an anisotropic texture. An AFM layer is then deposited over the magnetic layer.
    Type: Grant
    Filed: November 17, 2005
    Date of Patent: April 28, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew Joseph Carey, Jeffrey Robinson Childress, James Mac Freitag, Stefan Maat, Mustafa Michael Pinarbasi
  • Publication number: 20090091864
    Abstract: A current-perpendicular-to-the-plane (CPP) spin-valve (SV) magnetoresistive sensor uses an antiparallel (AP) pinned structure and has a ferromagnetic alloy comprising Co, Fe and Si in the reference layer of the AP-pinned structure and optionally in the CPP-SV sensor's free layer. The reference layer or AP2 layer is a multilayer of a first AP2-1 sublayer that contains no Si and is in contact with the AP-pinned structure's antiparallel coupling (APC) layer, and a second AP2-2 sublayer that contains Si and is in contact with the CPP-SV sensor's spacer layer. The Si-containing alloy may consist essentially of only Co, Fe and Si according to the formula (CoxFe(100-X))(100-y)Siy where the subscripts represent atomic percent, x is between about 45 and 55, and y is between about 20 and 30.
    Type: Application
    Filed: October 4, 2007
    Publication date: April 9, 2009
    Applicant: HITACHI GLOBAL STORAGE TECHNOLOGIES NETHERLANDS B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
  • Publication number: 20090086385
    Abstract: A magnetoresistive sensor having a greatly reduced read gap. The sensor has a pinned layer structure formed above the free layer. A layer of antiferromagnetic material (AFM layer) is formed over the pinned layer structure and has a front edge disposed toward, but recessed from the air bearing surface. An electrically conductive, magnetic lead is formed over the pinned layer and AFM layer such that the lead fills a space between the AFM layer and the air bearing surface. In this way, the read gap is distance between the outermost portion of the pinned layer structure and free layer. The thickness of the AFM layer and capping layer are not included in the read gap.
    Type: Application
    Filed: September 27, 2007
    Publication date: April 2, 2009
    Inventors: Hardayal Singh Gill, Wipul Pemsiri Jayasekara
  • Patent number: 7511926
    Abstract: A current perpendicular to plane (CPP) giant magnetoresistive (GMR) sensor having two dual spin valves sharing a common self pinned pinned layer.
    Type: Grant
    Filed: June 14, 2004
    Date of Patent: March 31, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Publication number: 20090080123
    Abstract: The high quality magnetoresistance effect element is capable of reducing resistance in the perpendicular-plane direction and preventing performance deterioration of a barrier layer. The magnetoresistance effect element comprises: a free layer; a pinned magnetic layer; and a barrier layer being provided between the free layer and the pinned magnetic layer, and the barrier layer is composed of a semiconductor.
    Type: Application
    Filed: July 28, 2008
    Publication date: March 26, 2009
    Applicants: FUJITSU LIMITED
    Inventors: Yuji Uehara, Koujiro Komagaki, Masashi Kawasaki
  • Patent number: 7506429
    Abstract: A magnetoresistive sensor having a well defined track width and method of manufacture thereof.
    Type: Grant
    Filed: February 7, 2005
    Date of Patent: March 24, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Howard Gordon Zolla, Edward Hin Pong Lee, Kim Y. Lee, Tsann Lin, Chun-Ming Wang
  • Patent number: 7504927
    Abstract: The present invention provides a current sensor capable of sensing a current to be detected with high precision while realizing a compact configuration. The current sensor includes a first MR element including element patterns disposed at a first level, a second MR element including element patterns disposed at a second level, and a thin film coil which winds at a third level provided between the first and second levels while including winding body portions extending in an X axis direction in correspondence with the element patterns of the first and second MR elements, and which applies a current magnetic field to each of the element patterns when a current to be detected is supplied. Therefore, by using both of the first and second MR elements, the current magnetic field can be detected with high sensitivity and high precision.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: March 17, 2009
    Assignee: TDK Corporation
    Inventor: Shigeru Shoji
  • Patent number: 7501928
    Abstract: The present invention provides a compact current sensor capable of measuring a current to be detected with high precision. A current sensor includes: a first magnetoresistive element including a plurality of element patterns which extend in an X axis direction at a first level, are disposed so as to be adjacent to each other in a Y axis direction orthogonal to the X axis direction, and are connected in parallel with each other; and a thin film coil which includes a plurality of winding body portions extending in the X axis direction in correspondence with the element patterns and winds at a second level different from the first level, and applies a current magnetic field to each of the element patterns when a current to be detected is supplied. Therefore, the absolute value of the resistance change amount in the magnetoresistive element increases. While realizing a compact configuration, the current to be detected, flowing in the thin film coil can be measured with high precision.
    Type: Grant
    Filed: November 18, 2005
    Date of Patent: March 10, 2009
    Assignee: TDK Corporation
    Inventor: Shigeru Shoji
  • Patent number: 7500303
    Abstract: A read head for a disk drive and a method of fabricating the read head with overlaid lead pads that contact the top surface of the sensor between the hardbias structures to define the electrically active region of the sensor are described. The invention deposits the GMR and lead layers before milling away the unwanted material. A photoresist mask with a hole defining the active area of the sensor is preferably patterned over a layer of DLC that is formed into a mask. A selected portion of the exposed lead material is then removed using the DLC as a mask defining the active region of the sensor. A photoresist mask pad is patterned to define the full sensor width. The excess sensor and lead material exposed around the mask is milled away. The layers for the hardbias structure are deposited.
    Type: Grant
    Filed: May 19, 2006
    Date of Patent: March 10, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tsung Yuan Chen, Kuok San Ho, Mustafa Michael Pinarbasi
  • Publication number: 20090059444
    Abstract: A two-axis, single-chip external magnetic field sensor incorporates tunneling magneto-resistance (TMR) technology. In one embodiment, an integrated device includes at least two sensor elements having pinned layers with orientation situated at a known angle (e.g., 90 degrees) with respect to each other. In the presence of a magnetic field, the information from the multiple sensor elements can be processed (e.g., using a conventional bridge configuration) to determine the orientation of the integrated sensor with respect to the external field. In order to achieve an integrated sensor with multiple pinned layer orientations, a novel processing method utilizes antiferromagnetic pinning layers different materials with different blocking temperatures (e.g., PtMn and IrMn).
    Type: Application
    Filed: August 30, 2007
    Publication date: March 5, 2009
    Applicant: FREESCALE SEMICONDUCTOR, INC.
    Inventors: Phillip Glenn Mather, Jijun Sun, Young Sir Chung
  • Patent number: 7497008
    Abstract: An embodiment of the invention is a magnetic head with overlaid lead pads that contact the top surface of the sensor between the hardbias structures and do not contact the hardbias structures which are electrically insulated from direct contact with the sensor. The lead pad contact area on the top of the sensor is defined by sidewall deposition of a conductive material to form leads pads on a photoresist prior to formation of the remainder of the leads. The conductive material for the lead pads is deposited at a shallow angle to maximize the sidewall deposition on the photoresist, then ion-milled at a high angle to remove the conductive material from the field while leaving the sidewall material. An insulation layer is deposited on the lead material at a high angle, then milled at a shallow angle to remove insulation from the sidewall.
    Type: Grant
    Filed: August 24, 2005
    Date of Patent: March 3, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tsung Yuan Chen, Frederick Hayes Dill, James Mac Freitag, Kuok San Ho, Wipul Pemsiri Jayasekara, Kim Y. Lee, Mustafa Michael Pinarbasi, Ching Hwa Tsang, Patrick Rush Webb