Detail Of Free Layer Or Additional Film For Affecting Or Biasing The Free Layer Patents (Class 360/324.12)
  • Patent number: 8031442
    Abstract: A magnetic head for a hard disk drive having a CPP read head sensor that includes a layered sensor stack including a free magnetic layer and hard bias elements that are disposed on the sides of the free magnetic layer to provide a biasing magnetization for the free magnetic layer. To increase the coercivity of the hard bias elements, and thereby improve the biasing of the magnetization of the free magnetic layer, the ratio (t/H) of the thickness t to the height H of the hard bias elements is fabricated to be within the range of from approximately 1 to approximately 1/15.
    Type: Grant
    Filed: August 1, 2007
    Date of Patent: October 4, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 8031445
    Abstract: A magnetic sensor, formed from a pair of magnetically free layers located on opposing sides of a non-magnetic layer, and method for its manufacture, are described. Biasing these free layers to be roughly orthogonal to one another causes them to be magnetostatically coupled in a weak antiferromagnetic mode. This enables the low frequency noise spectra of the two free layers to cancel one another. Careful control of the SH/TW ratio is an important feature of the device.
    Type: Grant
    Filed: October 8, 2008
    Date of Patent: October 4, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Yuchen Zhou, Kunliang Zhang, Yu-Hsai Chen, Tong Zhao, Moris Dovek
  • Patent number: 8031444
    Abstract: The semiconductor oxide layer that forms a part of the spacer layer in the inventive giant magnetoresistive device (CPP-GMR device) is composed of zinc oxide of wurtzite structure that is doped with a dopant given by at least one metal element selected from the group consisting of Zn, Ge, V, and Cr in a content of 0.05 to 0.90 at %: there is the advantage obtained that ever higher MR ratios are achievable while holding back an increase in the area resistivity AR.
    Type: Grant
    Filed: October 21, 2008
    Date of Patent: October 4, 2011
    Assignee: TDK Corporation
    Inventors: Tsutomu Chou, Tomohito Mizuno, Koji Shimazawa, Yoshihiro Tsuchiya, Shinji Hara, Hironobu Matsuzawa
  • Patent number: 8015694
    Abstract: A “scissoring-type” current-perpendicular-to-the-plane (CPP) magnetoresistive sensor with dual ferromagnetic sensing or free layers separated by a nonmagnetic spacer layer has improved stability as a result of etch-induced uniaxial magnetic anisotropy in each of the free layers. Each of the two ferromagnetic free layers has an etch-induced uniaxial magnetic anisotropy and an in-plane magnetic moment substantially parallel to its uniaxial anisotropy in the quiescent state, i.e., the absence of an applied magnetic field. The etch-induced uniaxial anisotropy of each of the free layers is achieved either by direct ion etching of each of the free layers, and/or by ion etching of the layer on which each of the free layers is deposited. A strong magnetic anisotropy is induced in the free layers by the etching, which favors generally orthogonal orientation of the two free layers in the quiescent state.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: September 13, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat, Neil Smith
  • Patent number: 8018691
    Abstract: A magnetoresistive sensor having a scissor free layer design and no pinned layer. The sensor includes first and second free layers that have magnetizations that are oriented at 90 degrees to one another and has a third magnetic layer with a magnetization that is antiparallel coupled with one of the free layers. The antiparallel coupling of the third magnetic layer with one of the free layers, allows the sensor to be used in a tunnel valve design, having an electrically insulating barrier layer between the free layers. The tunnel valve design reduces spin torque noise in the sensor, and the presence of the third magnetic layer allows the free layers to remain bias at 90 degrees to one another in spite of interfacial coupling through the very thin barrier layer.
    Type: Grant
    Filed: October 20, 2008
    Date of Patent: September 13, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Hardayal Singh Gill, Chang-Man Park
  • Patent number: 8018690
    Abstract: A CPP MTJ or GMR read sensor is provided in which the free layer is self-stabilized by a magnetization in a circumferential vortex configuration. This magnetization permits the pinned layer to be magnetized in a direction parallel to the ABS plane, which thereby makes the pinned layer directionally more stable as well. The lack of lateral horizontal bias layers or in-stack biasing allows the formation of closely configured shields, thereby providing protection against side-reading. The vortex magnetization is accomplished by first magnetizing the free layer in a uniform vertical field, then applying a vertical current while the field is still present.
    Type: Grant
    Filed: March 27, 2008
    Date of Patent: September 13, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Tai Min, Pokang Wang, Min Li, Otto Vogeli
  • Patent number: 8018693
    Abstract: A magnetic detector includes a magnetoresistive element and an impact sensor. The magnetoresistive element has a plurality of element-constituent layers that are stacked and include a free layer having a magnetization direction that changes in response to a magnetic field to be detected by the magnetic detector. The impact sensor has a plurality of sensor-constituent layers that are made of materials the same as those of the element-constituent layers and stacked in the same order as the element-constituent layers. The plurality of sensor-constituent layers include an impact detecting layer corresponding to the free layer and having a magnetization direction that changes by an inverse magnetostrictive effect in response to distortion created in the impact detecting layer by an impact received by the magnetic detector. The impact detecting layer exhibits a greater amount of change in magnetization direction when the magnetic detector receives an impact, compared with the free layer.
    Type: Grant
    Filed: January 21, 2009
    Date of Patent: September 13, 2011
    Assignee: TDK Corporation
    Inventor: Takumi Yanagisawa
  • Patent number: 8018692
    Abstract: A thin film magnetic head has a magneto-resistive (MR) effect element including an MR effect film formed by sequentially layering a magnetic pinned layer, a nonmagnetic layer and a free layer, and a pair of bias magnetic field application layers formed at junction tapered parts formed on both end parts of the magneto-resistive effect film in the width direction via insulating layers. Further, magnetic pinned layer oxidized films whose thickness is Hx (unit: nm) are disposed on end parts of the magnetic pinned layer at the junction tapered parts, free layer oxidized films whose thickness is Hf (unit: nm) are disposed on end parts of the free layer at the junction tapered parts, and the oxidized films are configured such that the thickness ratio (Hx/Hf) is not more than 0.5.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: September 13, 2011
    Assignee: TDK Corporation
    Inventor: Takayasu Kanaya
  • Patent number: 8014108
    Abstract: The invention provides a magnetoresistive device of the CPP (current perpendicular to plane) structure, comprising a magnetoresistive unit, and a first shield layer and a second shield layer which are located and formed such that the magnetoresistive unit is sandwiched between them from above and below, with a sense current applied in the stacking direction, wherein said magnetoresistive unit comprises a non-magnetic intermediate layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked and formed such that said nonmagnetic intermediate layer is sandwiched between them.
    Type: Grant
    Filed: February 8, 2008
    Date of Patent: September 6, 2011
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Tsutomu Chou, Daisuke Miyauchi
  • Patent number: 8011084
    Abstract: A method for manufacturing a manufacturing a magnetoresistive sensor that allows the sensor to be constructed with a very narrow and well controlled track width. The method includes depositing a layer of diamond like carbon over a series of sensor layers. A first mask is then formed to define a sensor, and an ion milling is performed to remove sensor material not protected by the first mask. Then, a second mask is formed, and a hard bias layer is deposited to the thickness of the sensor layers. The second mask is then lifted off and a CMP is performed to remove the first mask structure. Because all areas other than the area directly over the sensor are substantially planar a quick, gentle CMP can be used to remove the first mask layer even if the first mask is small, such as for definition of a very narrow track-width sensor.
    Type: Grant
    Filed: July 31, 2008
    Date of Patent: September 6, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Quang Le, Jui-Lung Li
  • Patent number: 8014109
    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: Grant
    Filed: October 4, 2007
    Date of Patent: September 6, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat
  • Patent number: 8012316
    Abstract: A method of forming 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 Co50Fe50 or Co75Fe25 single layer. MR ratio is also increased and 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: August 25, 2009
    Date of Patent: September 6, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Dan Abels, Min Li, Chyu-Jiuh Torng, Chen-Jung Chien, Yu-Hsia Chen
  • Patent number: 8009392
    Abstract: Foundation layers of a thin film magnetic head are disposed between insulating layers and bias magnetic field application layers, and are configured of Cr or Cr alloy. The insulating layers are configured of a Si oxide such that the Si content of the Si oxide is in the range of 30˜56 at % (atom %) and that the atom ratio of oxygen to Si (O/Si) is in the range of 0.8˜1.3. With the configuration, the occurrence rate of noise is reduced.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: August 30, 2011
    Assignee: TDK Corporation
    Inventors: Takayasu Kanaya, Kei Hirata, Yohei Koyanagi, Seiichi Takayama, Shinji Hara, Toshiyuki Ayukawa
  • Patent number: 8004800
    Abstract: A magnetoresistive sensor having a hard bias structure that provides improved bias field robustness. The sensor includes a nitrogenated hard bias layer and a seed layer that include a nitrogenated NiTa layer and a layer of Ru. The seed layer can also include a layer of CrMn disposed between the layer of NiTa and the layer of Ru. The novel seed structure allows a nitrogenated hard bias layer to be used, while maintaining a high magnetic coercivity of the hard bias layer.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: August 23, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: James Mac Freitag
  • Patent number: 8000065
    Abstract: A magnetoresistive element includes: a detection surface that receives a magnetic field to be detected; a free layer made of a ferromagnetic material, having an end face located in the detection surface, and exhibiting a change in magnetization direction in response to the magnetic field to be detected; a pinned layer made of a ferromagnetic material, disposed away from the detection surface, and having a fixed magnetization direction; and a coupling portion made of a nonmagnetic material and coupling the free layer to the pinned layer. The coupling portion includes a nonmagnetic conductive layer that allows electrons to be conducted while conserving their spins.
    Type: Grant
    Filed: January 28, 2009
    Date of Patent: August 16, 2011
    Assignee: TDK Corporation
    Inventor: Hiroshi Yamazaki
  • Patent number: 7999336
    Abstract: In order to increase an efficiency of spin transfer and thereby reduce the required switching current, a current perpendicular to plane (CPP) magnetic element for a memory device includes either one or both of a free magnetic layer, which has an electronically reflective surface, and a permanent magnet layer, which has perpendicular anisotropy to bias the free magnetic layer.
    Type: Grant
    Filed: April 24, 2008
    Date of Patent: August 16, 2011
    Assignee: Seagate Technology LLC
    Inventors: Dexin Wang, Dimitar V. Dimitrov, Song S. Xue, Insik Jin
  • Patent number: 7990659
    Abstract: A magnetic head according to one embodiment includes a substrate; a sensor formed above the substrate; a second shield formed above the sensor and the substrate; a first insulation layer positioned between the substrate and the sensor; a second insulation layer positioned between the sensor and the second shield; and a nonmagnetic, non-electrically insulative layer formed between the substrate and the sensor.
    Type: Grant
    Filed: July 9, 2007
    Date of Patent: August 2, 2011
    Assignee: International Business Machines Corporation
    Inventors: Robert Glenn Biskeborn, Calvin Shyhjong Lo, Jason Liang, Teya Topuria
  • Patent number: 7989223
    Abstract: A spin injection device capable of spin injection magnetization reversal at low current density, a magnetic apparatus using the same, and magnetic thin film using the same, whereby the spin injection device (14) including a spin injection part (1) comprising a spin polarization part (9) including a ferromagnetic fixed layer (26) and an injection junction part (7) of nonmagnetic layer, and a ferromagnetic free layer (27) provided in contact with the spin injection part (1) is such that in which the nonmagnetic layer (7) is made of either an insulator (12) or a conductor (25), a nonmagnetic layer (28) is provided on the surface of the ferromagnetic free layer (27), electric current is flown in the direction perpendicular to the film surface of the spin injection device (14), and the magnetization of the ferromagnetic free layer (27) is reversed. This is applicable to such various magnetic apparatuses and magnetic memory devices as super gigabit large capacity, high speed, non-volatile MRAM and the like.
    Type: Grant
    Filed: February 2, 2009
    Date of Patent: August 2, 2011
    Assignee: Japan Science and Technology Agency
    Inventors: Kouichiro Inomata, Nobuki Tezuka
  • Patent number: 7985599
    Abstract: Arrays of spin-valve elements that can be selectively activated to trap, hold, manipulate and release magnetically tagged biological and chemical particles, including molecules and polymers. The spin-valve elements that can be selectively activated and deactivated by applying a momentary applied magnetic field thereto. The spin valve element array can be used for selectively sorting and transporting magnetic particles one particle at a time within the array. As the magnetically tagged particles are held by the spin-valve elements, application of an auxiliary magnetic field can be used to apply tension or torsion to the held particles or to move, e.g. rotate, the trapped particles. The arrays of spin-valve elements can be used in a variety of applications including drug screening, nucleic acid sequencing, structural control and analysis of RNA/DNA and proteins, medical diagnosis, and magnetic particle susceptibility and size homogenization for other medical applications.
    Type: Grant
    Filed: February 13, 2007
    Date of Patent: July 26, 2011
    Assignee: The United States of America as represented by the Secretary of Commerce, The National Institute of Standards and Technology
    Inventors: John Moreland, Elizabeth Mirowski, Stephen E. Russek
  • Patent number: 7974048
    Abstract: The invention provides a magneto-resistive effect device of the CPP (current perpendicular to plane) structure, having a magneto-resistive effect unit, and a first shield layer and a second shield layer located and formed such that the magneto-resistive effect unit is sandwiched between them, with a sense current applied in a stacking direction.
    Type: Grant
    Filed: November 28, 2007
    Date of Patent: July 5, 2011
    Assignee: TDK Corporation
    Inventors: Koji Shimazawa, Daisuke Miyauchi, Yoshihiro Tsuchiya, Takahiko Machita, Shinji Hara
  • Patent number: 7965474
    Abstract: A magnetic oscillation element includes a magnetization fixing layer whose magnetization direction is substantially pinned toward one direction, a nonmagnetic layer that is disposed on the magnetization fixing layer, and a magnetization free layer whose magnetization direction fluctuates. The magnetization free layer is disposed on the nonmagnetic layer. A pair of electrodes apply a current in a direction perpendicular to the film surface of the magnetization fixing layer, the nonmagnetic layer, and the magnetization free layer. The magnetization free layer is excited with a magnetization vibration caused by spin transfer from the magnetization fixing layer due to the appliance of the current.
    Type: Grant
    Filed: September 24, 2007
    Date of Patent: June 21, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Rie Sato, Koichi Mizushima, Kiwamu Kudo
  • Patent number: 7957107
    Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive sensor has an antiparallel free (APF) structure as the free layer and a specific direction for the applied bias or sense current. The (APF) structure has a first free ferromagnetic (FL1), a second free ferromagnetic layer (FL2), and an antiparallel (AP) coupling (APC) layer that couples FL1 and FL2 together antiferromagnetically with the result that FL1 and FL2 have substantially antiparallel magnetization directions and rotate together in the presence of a magnetic field. The thickness of FL1 is preferably greater than the spin-diffusion length of the electrons in the FL1 material. The minimum thickness for FL2 is a thickness resulting in a FL2 magnetic moment equivalent to at least 10 ? Ni80Fe20 and preferably to at least 15 ? Ni80Fe20.
    Type: Grant
    Filed: July 14, 2009
    Date of Patent: June 7, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat, Neil Smith
  • Patent number: 7950136
    Abstract: A process to manufacturing a TMR read head with improved voltage breakdown is performed by laying down the AP1 layer as two or more layers. Each AP1 sub-layer is exposed to a low energy plasma for a short time before the next layer is deposited. This results in a smooth surface, onto which to deposit the tunneling barrier layer, with no disruption of the surface crystal structure of the completed AP1 layer.
    Type: Grant
    Filed: May 12, 2008
    Date of Patent: May 31, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Tong Zhao, Chyu-Jiuh Torng, Hui-Chuan Wang
  • Patent number: 7950135
    Abstract: A manufacturing method of an MR element in which current flows in a direction perpendicular to layer planes, includes a step of forming on a lower electrode layer an MR multi-layered structure with side surfaces substantially perpendicular to the layer lamination plane, a step of forming a first insulation layer on at least the side surfaces of the formed MR multi-layered structure, a step of forming a second insulation layer and a magnetic domain control bias layer on the lower electrode layer, and a step of forming an upper electrode layer on the MR multi-layered structure and the magnetic domain control bias layer.
    Type: Grant
    Filed: May 31, 2007
    Date of Patent: May 31, 2011
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Takayasu Kanaya
  • Patent number: 7939188
    Abstract: A magnetic stack having a free layer having a switchable magnetization orientation, a reference layer having a pinned magnetization orientation, and a barrier layer therebetween. The stack includes an annular antiferromagnetic pinning layer electrically isolated from the free layer and in physical contact with the reference layer. In some embodiments, the reference layer is larger than the free layer.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: May 10, 2011
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Antoine Khoueir, Brian Lee, Pat Ryan, Michael Tang, Insik Jin, Paul E. Anderson
  • Patent number: 7935435
    Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.
    Type: Grant
    Filed: September 19, 2008
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Haiwen Xi
  • Patent number: 7936539
    Abstract: A bottom spin-valve GMR sensor has been fabricated that has ultra-thin layers of high density and smoothness. In addition, these layers are inherently furnished with sub-monolayer thick oxygen surfactant layers. The sensor is fabricated using a method in which the layers are sputtered in a mixture of Ar and O2. A particularly novel feature of the method is the use of a sputtering chamber with an ultra-low base pressure and correspondingly ultra-low pressure mixtures of Ar and O2 sputtering gas (<0.5 millitorr) in which the admixed oxygen has a partial pressure of less than 5×10?9 torr.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: May 3, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 7931976
    Abstract: A magnetic recording element includes a multilayer having a surface and a pair of electrodes. The multilayer has a first magnetic fixed layer whose magnetization is substantially fixed in a first direction substantially perpendicular to the surface. The multilayer also has a second magnetic fixed layer whose magnetization is substantially fixed in a second direction opposite to the first direction substantially perpendicular to the surface. A third magnetic layer is provided between the first and second magnetic layers. The direction of magnetization of the third ferromagnetic layer is variable. A first intermediate layer is provided between the first and the third magnetic layers. A second intermediate layer is provided between the second and the third magnetic layers. The pair of electrodes is capable of supplying an electric current flowing in a direction substantially perpendicular to the surface to the multilayer.
    Type: Grant
    Filed: October 3, 2008
    Date of Patent: April 26, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuichi Ohsawa, Shiho Nakamura, Hirofumi Morise, Satoshi Yanagi, Daisuke Saida
  • Patent number: 7929259
    Abstract: A magnetic sensor includes a sensor stack having a first magnetic portion, a second magnetic portion, and a barrier layer between the first magnetic portion and the second magnetic portion. At least one of the first magnetic portion and the second magnetic portion includes a multilayer structure having a first magnetic layer having a positive magnetostriction adjacent to the barrier layer, a second magnetic layer, and an intermediate layer between the first magnetic layer and the second magnetic layer. The magnetic sensor has an MR ratio of at least about 80% when the magnetic sensor has a resistance-area (RA) product of about 1.0 ?·?m2.
    Type: Grant
    Filed: June 16, 2010
    Date of Patent: April 19, 2011
    Assignee: Seagate Technology LLC
    Inventors: Zheng Gao, Brian W. Karr, Song Xue, Eric L. Granstrom, Khuong T. Tran, Yi X. Li
  • Patent number: 7929258
    Abstract: A magnetic sensor includes a reference layer having a first magnetization direction and a free layer assembly having an effective magnetization direction substantially perpendicular to the first magnetization direction and substantially perpendicular to a plane of each layer of the free layer assembly. A spacer layer is between the reference layer and the free layer, and a signal enhancement layer is exchange coupled to the free layer assembly on a side opposite the spacer layer.
    Type: Grant
    Filed: January 22, 2008
    Date of Patent: April 19, 2011
    Assignee: Seagate Technology LLC
    Inventors: Song S. Xue, Zheng Gao, Shaoping Li, Kaizhong Gao, Dimitar V. Dimitrov, Konstantin Nikolaev, Patrick J. Ryan
  • Patent number: 7918014
    Abstract: A CPP-GMR spin valve having a CoFe/NiFe composite free layer is disclosed in which Fe content of the CoFe layer ranges from 20 to 70 atomic % and Ni content in the NiFe layer varies from 85 to 100 atomic % to maintain low Hc and ?S values. A small positive magnetostriction value in a Co75Fe25 layer is used to offset a negative magnetostriction value in a Ni90Fe10 layer. The CoFe layer is deposited on a sensor stack in which a seed layer, AFM layer, pinned layer, and non-magnetic spacer layer are sequentially formed on a substrate. After a NiFe layer and capping layer are sequentially deposited on the CoFe layer, the sensor stack is patterned to give a sensor element with top and bottom surfaces and a sidewall connecting the top and bottom surfaces. Thereafter, a dielectric layer is formed adjacent to the sidewalls.
    Type: Grant
    Filed: July 13, 2005
    Date of Patent: April 5, 2011
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yu-Hsia Chen, Chyu-Jiuh Torng
  • Patent number: 7916429
    Abstract: A magnetic field detecting element comprising: a stack including an upper and magnetic layer, a lower magnetic layer, and a non-magnetic intermediate layer sandwiched therebetween, an upper and lower shield electrode layer provided in a manner that they sandwich said stack therebetween in a direction of stacking of the stack, wherein the upper and lower shield electrode layer supply sense current in the direction of stacking and magnetically shield the stack; a bias magnetic layer provided on a surface of the stack, the surface being opposite to an air bearing surface of said stack, and insulating films provided on both sides of the stack with regard to a track width direction thereof. The bias magnetic layer has a larger thickness than the stack, and the upper shield electrode layer and/or said lower shield electrode layer includes an auxiliary shield layer which fills a stepped portion formed by the stack and bias magnetic layer.
    Type: Grant
    Filed: July 30, 2007
    Date of Patent: March 29, 2011
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Takahiko Machita
  • Patent number: 7916430
    Abstract: A thin-film magnetic head includes a lower magnetic shield layer, an MR multi-layered structure formed on the lower magnetic shield layer so that current flows in a direction perpendicular to surfaces of laminated layers, an upper magnetic shield layer formed on the MR multi-layered structure, and an additional lower magnetic shield layer directly laminated on the lower magnetic shield layer outside both side ends in a track-width direction of the MR multi-layered structure. The additional lower magnetic shield layer is directly contacted with both side surfaces in a track-width direction of the MR multi-layered structure. A top surface of the additional lower magnetic shield layer is positioned higher in height than a top surface of the lower magnetic shield layer in a region where the MR multi-layered structure is formed.
    Type: Grant
    Filed: August 9, 2007
    Date of Patent: March 29, 2011
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Takayasu Kanaya
  • Patent number: 7916433
    Abstract: A method and system for providing a magnetic element are described. The method and system include providing a pinned layer, a barrier layer, and a free layer. The free layer includes a first ferromagnetic layer, a second ferromagnetic layer, and an intermediate layer between the first ferromagnetic layer and the second ferromagnetic layer. The barrier layer resides between the pinned layer and the free layer and includes MgO. The first ferromagnetic layer resides between the barrier layer and the intermediate layer. The first ferromagnetic layer includes at least one of CoFeX and CoNiFeX, with X being selected from the group of B, P, Si, Nb, Zr, Hf, Ta, Ti, and being greater than zero atomic percent and not more than thirty atomic percent. The first ferromagnetic layer is ferromagnetically coupled with the second ferromagnetic layer.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: March 29, 2011
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Zhitao Diao, Eugene Youjun Chen
  • Patent number: 7911745
    Abstract: A thin-film magnetic head includes a magneto-resistive effect device of the CPP structure including a multilayer film comprising a stack of a fixed magnetization layer, a nonmagnetic layer and a free layer stacked one upon another in order, with a sense current applied in the stacking direction of the multilayer film, and an upper shield layer and a lower shield layer with the magneto-resistive effect device held between them in the thickness direction, and further comprises a bias magnetic field-applying layer located at each end of the multilayer film in the widthwise direction and a re-magnetizer unit designed such that when the bias magnetic field-applying layers malfunction, they are re-magnetized to go back to normal.
    Type: Grant
    Filed: August 24, 2007
    Date of Patent: March 22, 2011
    Assignee: TDK Corporation
    Inventors: Yosuke Antoku, Tsuyoshi Umehara, Tetsuya Kuwashima
  • Patent number: 7900342
    Abstract: Magnetoresistance sensors with magnetic pinned layers that are pinned by anisotropic etch induced magnetic anisotropies and methods for fabricating the magnetoresistance sensors are provided. The method comprises forming a seed layer structure. The seed layer is etched to form an anisotropic etch along a top surface of the seed layer. A magnetic pinned layer is formed on the top surface of the seed layer structure. The anisotropic etch on the top surface of the seed layer structure induces a magnetic anisotropy in the magnetic pinned layer, which pins the magnetization of the magnetic pinned layer structure.
    Type: Grant
    Filed: February 23, 2007
    Date of Patent: March 8, 2011
    Assignee: Hitachi Global Storage Technologies Netherlands, B.V.
    Inventors: James M. Freitag, Mustafa M. Pinarbasi
  • Patent number: 7895731
    Abstract: A method for manufacturing a magnetic field detecting element having a free layer whose magnetization direction is variable depending on an external magnetic field and a pinned layer whose magnetization direction is fixed and these are stacked with an electrically conductive, nonmagnetic spacer layer sandwiched therebetween, wherein sense current flows in a direction perpendicular to film planes of the magnetic field detecting element. The method comprises: forming a spacer adjoining layer adjacent to the spacer layer, Heusler alloy layer, and a metal layer successively in this order; and forming either at least a part of the pinned layer or the free layer by heating the spacer adjoining layer, the Heusler alloy layer, and the metal layer. The spacer adjoining layer has a layer chiefly made of cobalt and iron. The Heusler alloy layer includes metal which is silver, gold, copper, palladium, or platinum, or an alloy thereof. The metal layer is made of the same.
    Type: Grant
    Filed: June 22, 2007
    Date of Patent: March 1, 2011
    Assignee: TDK Corporation
    Inventors: Tomohito Mizuno, Yoshihiro Tsuchiya, Koji Shimazawa, Kei Hirata, Keita Kawamori
  • Patent number: 7898776
    Abstract: A tunneling magnetic sensing element is provided, in which an increase in the magnetostriction of a free magnetic layer is reduced and the rate of change in resistance is high. A laminate T1 constituting the tunneling magnetic sensing element includes a portion in which a pinned magnetic layer, a barrier layer, and a free magnetic layer are disposed in that order from the bottom. An enhancing layer disposed on the barrier layer side of the free magnetic layer includes a first enhancing layer on the barrier layer side and a second enhancing layer on the soft magnetic layer side, and the Fe content of a CoFe alloy constituting the first enhancing layer is specified to be larger than the Fe content of the CoFe alloy of the second enhancing layer.
    Type: Grant
    Filed: July 24, 2007
    Date of Patent: March 1, 2011
    Assignee: TDK Corporation
    Inventors: Ryo Nakabayashi, Naoya Hasegawn, Masamichi Saito, Masahiko Ishizone, Yosuke Ide, Takuya Seino, Kazumasa Nishimura
  • Patent number: 7898775
    Abstract: An MR element includes a free layer whose direction of magnetization changes in response to an external magnetic field. Two bias magnetic field applying layers are disposed adjacent to two side surfaces of the MR element. Each bias magnetic field applying layer includes a nonmagnetic intermediate layer, and a first magnetic layer and a second magnetic layer disposed to sandwich the intermediate layer. The first and second magnetic layers are antiferromagnetically exchange-coupled to each other through RKKY interaction.
    Type: Grant
    Filed: July 13, 2007
    Date of Patent: March 1, 2011
    Assignee: TDK Corporation
    Inventors: Kei Hirata, Shinji Hara, Takayasu Kanaya, Takeo Kagami
  • Patent number: 7897274
    Abstract: A magnetoresistive device includes a magnetization pinned layer, a magnetization free layer, a nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer, and electrodes allowing a sense current to flow in a direction substantially perpendicular to the plane of the stack including the magnetization pinned layer, the nonmagnetic intermediate layer and the magnetization free layer. At least one of the magnetization pinned layer and the magnetization free layer is substantially formed of a binary or ternary alloy represented by the formula FeaCobNic (where a+b+c=100 at %, and a?75 at %, b?75 at %, and c?63 at %), or formed of an alloy having a body-centered cubic crystal structure.
    Type: Grant
    Filed: March 13, 2007
    Date of Patent: March 1, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Masatoshi Yoshikawa, Yuzo Kamiguchi, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 7894165
    Abstract: The invention provides a magneto-resistive effect device having a CPP (current perpendicular to plane) structure comprising a nonmagnetic spacer layer, and a fixed magnetized layer and a free layer stacked one upon another with said nonmagnetic spacer layer sandwiched between them, with a sense current applied in a stacking direction, wherein said free layer functions such that its magnetization direction changes depending on an external magnetic field, and is made up of a multilayer structure including a Heusler alloy layer, wherein an Fe layer is formed on one of both planes of said Heusler alloy layer in the stacking direction, wherein said one plane is near to at least a nonmagnetic spacer layer side, and said fixed magnetization layer is made up of a multilayer structure including a Heusler alloy layer, wherein Fe layers are formed on both plane sides of said Heusler alloy layer in the stacking direction with said Heusler alloy layer sandwiched between them.
    Type: Grant
    Filed: June 13, 2007
    Date of Patent: February 22, 2011
    Assignee: TDK Corporation
    Inventors: Tomohito Mizuno, Yoshihiro Tsuchiya, Koji Shimazawa
  • Patent number: 7894168
    Abstract: The invention provides a thin-film magnetic head having a magneto-resistive effect device of the CPP (current perpendicular to plane) structure comprising a multilayer film in which a fixed magnetization layer, a nonmagnetic layer and a free layer are stacked together in order. The fixed magnetization layer, nonmagnetic layer and free layer extend away from an air bearing surface that is a plane in opposition to a medium, the length of the fixed magnetization layer in a depth direction normal to said air bearing surface is greater than the length of the free layer in the depth direction. A shunt layer for shunting the sense current is located at a farther distance in the depth direction than the free layer, and the shunt layer is separated from the free layer by a constant gap in the depth direction.
    Type: Grant
    Filed: August 28, 2007
    Date of Patent: February 22, 2011
    Assignee: TDK Corporation
    Inventors: Hiroshi Kiyono, Tetsuya Kuwashima
  • Patent number: 7894167
    Abstract: Provided is a magnetoresistive effect element in which a magneto-sensitive portion is formed in a position where the portion sufficiently receives bias field and the influence of reattachments on reading output is avoided. The magneto-sensitive portion has a pinned layer, a non-magnetic intermediate layer and a free layer. A multilayer, that includes a foundation layer, the magneto-sensitive portion and a cap layer, has upper side surfaces forming an inclination angle ?C, intermediate side surfaces forming an inclination angle ?S, and lower side surfaces forming an inclination angle ?U. The inclination angle ?S is greater than both of the inclination angles ?C and ?U. The boundary between the upper side surface and the intermediate side surface is located above a side surface of the magneto-sensitive portion, and the boundary between the intermediate side surface and the lower side surface is located below a side surface of the magneto-sensitive portion.
    Type: Grant
    Filed: March 9, 2007
    Date of Patent: February 22, 2011
    Assignee: TDK Corporation
    Inventors: Takayasu Kanaya, Kazuki Sato, Daisuke Miyauchi
  • Publication number: 20110032644
    Abstract: A method and system for providing a magnetic element and a magnetic memory utilizing the magnetic element are described. The magnetic element is used in a magnetic device that includes a contact electrically coupled to the magnetic element. The method and system include providing pinned, nonmagnetic spacer, and free layers. The free layer has an out-of-plane demagnetization energy and a perpendicular magnetic anisotropy corresponding to a perpendicular anisotropy energy that is less than the out-of-plane demagnetization energy. The nonmagnetic spacer layer is between the pinned and free layers. The method and system also include providing a perpendicular capping layer adjoining the free layer and the contact. The perpendicular capping layer induces at least part of the perpendicular magnetic anisotropy in the free layer. The magnetic element is configured to allow the free layer to be switched between magnetic states when a write current is passed through the magnetic element.
    Type: Application
    Filed: August 10, 2009
    Publication date: February 10, 2011
    Applicant: GRANDIS, INC.
    Inventors: Steven M. Watts, Zhitao Diao, Xueti Tang
  • Publication number: 20110026169
    Abstract: A dual current-perpendicular-to-plane scissor sensor according to one embodiment includes a middle free layer; two outer free layers positioned on opposite sides of the middle free layer; spacer layers between the middle free layer and each of the outer free layers; and a hard bias layer positioned behind the free layers relative to a media-facing surface of the sensor, wherein the free layers are about magnetostatically balanced.
    Type: Application
    Filed: July 28, 2009
    Publication date: February 3, 2011
    Inventors: Hardayal Singh Gill, Wen-Chien David Hsiao, Douglas Johnson Werner
  • Patent number: 7881021
    Abstract: A magnetoresistive device with CPP structure, comprising a nonmagnetic intermediate layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked and formed with said nonmagnetic intermediate layer interposed between them, wherein each of said first and second ferromagnetic layers comprises a sensor area joining to the nonmagnetic intermediate layer and a magnetization direction control area that extends further rearward from the position of the rear end of said nonmagnetic intermediate layer; a magnetization direction control multilayer arrangement is interposed at an area where the magnetization direction control area for said first ferromagnetic layer is opposite to the magnetization direction control area for said second ferromagnetic layer to produce magnetizations of the said first and second ferromagnetic layers which are antiparallel with each other; and said sensor area is provided at both width direction ends with biasing layers working such that the mutually antiparallel magnetiza
    Type: Grant
    Filed: January 30, 2008
    Date of Patent: February 1, 2011
    Assignee: TDK Corporation
    Inventors: Tsutomu Chou, Yoshihiro Tsuchiya, Daisuke Miyauchi, Takahiko Machita, Shinji Hara, Tomohito Mizuno, Hironobu Matsuzawa, Toshiyuki Ayukawa, Koji Shimazawa, Kiyoshi Noguchi
  • Patent number: 7880209
    Abstract: A free ferromagnetic data storage layer of an MRAM cell is coupled to a free ferromagnetic stabilization layer, which stabilization layer is directly electrically coupled to a contact electrode, on one side, and is separated from the free ferromagnetic data storage layer, on an opposite side, by a spacer layer. The spacer layer provides for the coupling between the two free layers, which coupling is one of: a ferromagnetic coupling and an antiferromagnetic coupling.
    Type: Grant
    Filed: October 9, 2008
    Date of Patent: February 1, 2011
    Assignee: Seagate Technology LLC
    Inventors: Haiwen Xi, Kaizhong Gao, Dimitar V. Dimitrov, Song S. Xue
  • Patent number: 7881023
    Abstract: The invention provides a magnetoresistive device with the CPP (current perpendicular to plane) structure, comprising a magnetoresistive unit, and a first shield layer and a second shield layer located and formed such that the magnetoresistive unit is sandwiched between them, with a sense current applied in a stacking direction, wherein the magnetoresistive unit comprises a nonmagnetic intermediate layer, and a first ferromagnetic layer and a second ferromagnetic layer stacked and formed such that the nonmagnetic intermediate layer is interposed between them, wherein the first shield layer, and the second shield layer is controlled by magnetization direction control means in terms of magnetization direction, and the first ferromagnetic layer, and the second ferromagnetic layer receives action such that there is an antiparallel magnetization state created, in which mutual magnetizations are in opposite directions, under the influences of magnetic actions of the first shield layer and the second shield layer.
    Type: Grant
    Filed: January 24, 2008
    Date of Patent: February 1, 2011
    Assignee: TDK Corporation
    Inventors: Takahiko Machita, Koji Shimazawa, Daisuke Miyauchi, Tsutomu Chou
  • Patent number: 7876537
    Abstract: An MR element incorporates a layered structure. The layered structure includes: a spacer layer having a first surface and a second surface that face toward opposite directions; a free layer disposed adjacent to the first surface of the spacer layer and having a direction of magnetization that changes in response to a signal magnetic field; and a pinned layer disposed adjacent to the second surface of the spacer layer and having a fixed direction of magnetization. The spacer layer is a layer at least part of which is made of a material other than a conductor, and the spacer layer intercepts the passage of currents or limits the passage of currents as compared with a layer entirely made of a conductor. The MR element further incorporates a conductive film that is disposed on the peripheral surface of the layered structure and allows conduction between the free layer and the pinned layer.
    Type: Grant
    Filed: April 25, 2007
    Date of Patent: January 25, 2011
    Assignee: TDK Corporation
    Inventors: Takumi Uesugi, Tetsuro Sasaki, Takeo Kagami, Kei Hirata
  • Publication number: 20110007431
    Abstract: A spin torque oscillator device having a magnetic free layer with a magnetic anisotropy that has a component that is oriented perpendicular to a direction of an applied magnetic field. The spin torque oscillator device includes a magnetic reference layer, a magnetic free layer and a non-magnetic layer sandwiched there-between. A component of the magnetic anisotropy of the free layer can be oriented perpendicular to a magnetization of the reference layer, and this orientation relative to the magnetization of the reference layer can be either in lieu of or in addition to its orientation relative to the applied magnetic field. The magnetic anisotropy cants the magnetization of the free layer which would otherwise be oriented antiparallel with the magnetization of the reference layer. The magnetic anisotropy in the free layer improves performance of the spin torque sensor by reducing noise.
    Type: Application
    Filed: September 16, 2010
    Publication date: January 13, 2011
    Inventors: Patrick M. Braganca, Bruce A. Gurney