Detail Of Pinned Film Or Additional Film For Affecting Or Biasing The Pinned Film Patents (Class 360/324.11)
  • Patent number: 9065043
    Abstract: A tunnel magnetoresistance (TMR) read sensor having a tabbed AFM layer and an extended pinned layer and methods for making the same are provided. The TMR read sensor has an AFM layer recessed from the air bearing surface, providing a reduced shield-to-shield distance.
    Type: Grant
    Filed: April 1, 2014
    Date of Patent: June 23, 2015
    Assignee: Western Digital (Fremont), LLC
    Inventors: Rongfu Xiao, Guanxiong Li, Zhihong Zhang, Ming Mao, Chen-Jung Chien
  • Patent number: 9053721
    Abstract: A magnetic read sensor having a magnetic seed layer, a pinned layer structure formed over the magnetic seed layer, a non-magnetic barrier or spacer layer formed over the pinned layer structure and a magnetic free layer structure formed over the non-magnetic barrier or spacer layer. The pinned layer has a stripe height (measured from the media facing surface) that is greater than a stripe height of the magnetic free layer structure. In addition, the magnetic seed layer structure has a stripe height (also measured from the media facing surface) that is greater than the stripe height of the magnetic pinned layer structure and the magnetic free layer structure. The stripe height of the magnetic seed layer structure can be controlled independently of the stripe heights of the magnetic pinned layer structure and the magnetic free layer structure.
    Type: Grant
    Filed: May 30, 2014
    Date of Patent: June 9, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Yongchul Ahn, David P. Druist, Zheng Gao, Ying Hong, Yunhe Huang, Quang Le, Thomas L. Leong, Guangli Liu, Xiaoyong Liu, David J. Seagle
  • Patent number: 9042062
    Abstract: A magnetic read sensor having an antiferromagnetic located embedded within a magnetic shield of the sensor so that the antiferromagnetic layer can pin the magnetization of the pinned layer without contributing to read gap thickness. The sensor is configured with a pinned layer having a free layer structure located within an active area of the sensor and a pinned layer that extends beyond the free layer and active area of the sensor. The antiferromagnetic layer can be located outside of the active and exchange coupled with the extended portion of the pinned layer.
    Type: Grant
    Filed: August 27, 2013
    Date of Patent: May 26, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Ying Hong, Quang Le, Masaya Nishioka
  • Patent number: 9030785
    Abstract: The embodiments of the present invention relate to a magnetic read head with pinned layers extending to the ABS of the read head and in contact with an antiferromagnetic layer that is recessed in relation to the ABS of the read head. The recessed antiferromagnetic layer may be disposed above or below the pinned layer structure and provides a pinning field to prevent amplitude flipping in head operation. In these embodiments of the present invention, the read gap of the sensor, that is the distance between the highly permeable, magnetically soft upper and lower shield layers at the ABS, is reduced by the thickness of the antiferromagnetic layer.
    Type: Grant
    Filed: June 21, 2013
    Date of Patent: May 12, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: James Mac Freitag, Zheng Gao
  • Patent number: 9013837
    Abstract: A magnetoresistive element according to an embodiment includes: a magnetoresistance effect film including: a first magnetic film; a second magnetic film; and an intermediate film of a nonmagnetic material disposed between the first magnetic film and the second magnetic film, at least one of the first magnetic film and the second magnetic film being formed of a material expressed as AxB1?x(65 at %?x?85 at %) where A is an alloy containing Co and at least one element selected from Fe and Mn, and B is an alloy containing Si or Ge, a Si concentration in the at least one of the first magnetic film and the second magnetic film decreasing and a Ge concentration increasing as a distance from the intermediate film increases.
    Type: Grant
    Filed: March 12, 2014
    Date of Patent: April 21, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoki Hase, Masayuki Takagishi, Susumu Hashimoto, Shuichi Murakami, Yousuke Isowaki, Masaki Kado, Hitoshi Iwasaki
  • Patent number: 9007729
    Abstract: In one embodiment, a read sensor includes an antiferromagnetic (AFM) pinning layer, the AFM pinning layer being recessed from a media-facing surface in an element height direction to a first height, a first antiparallel pinned multilayer (AP1) positioned above the AFM pinning layer and extending beyond the first height to the media-facing surface, a second antiparallel pinned layer (AP2) positioned above the AP1 and extending beyond the first height to the media-facing surface, and a free layer positioned at the media-facing surface above the AP2 and extending from the media-facing surface in the element height direction to a second height, wherein the element height direction is perpendicular to the media-facing surface, wherein the AP1 and the AP2 are not recessed from the media-facing surface, and wherein the AFM, the AP1, and the AP2 extend beyond the free layer in the element height direction beyond the second height.
    Type: Grant
    Filed: April 29, 2014
    Date of Patent: April 14, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Kuok S. Ho, Suping Song
  • Patent number: 9007727
    Abstract: A magnetic head having a CPP read head sensor that includes a layered sensor stack including an antiferromagnetic (AFM) layer, a pinned magnetic layer, and a free magnetic layer. The pinned magnetic layer is comprised of a high, positive magnetostriction material and has a thickness t and a height (H), such that the ratio (t/H) of the thickness t to the height H of the pinned magnetic layer is fabricated to be within the range of from approximately 1/10 to approximately 1/500. Ion milling is conducted at a grazing angle to the surface of the layer upon which the pinned magnetic layer is fabricated, where the ion beam is oriented in the direction of the desired magnetization of the pinned magnetic layer.
    Type: Grant
    Filed: July 17, 2007
    Date of Patent: April 14, 2015
    Assignee: HGST Netherlands B.V.
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 9007728
    Abstract: A method comprises providing a magnetic element including a free layer, a pinned layer, a nonmagnetic spacer layer between the free and pinned layers, and a pinning layer adjacent the pinned layer. The free layer is biased in a first direction. The pinned layer has a first layer having a first magnetization, a second layer having a second magnetization, and a nonmagnetic layer between the first and second layer. The first magnetization is pinned parallel to a second direction substantially perpendicular to the first direction and substantially perpendicular to the ABS. The second magnetization is antiparallel to the second direction. The pinning layer is oriented along the second direction. The method further comprises providing a hard bias structure having a hard bias magnetization, initializing the hard bias magnetization along the second direction, performing at least one thermal treatment, and resetting the hard bias magnetization substantially along the first direction.
    Type: Grant
    Filed: June 26, 2012
    Date of Patent: April 14, 2015
    Assignee: Western Digital (Fremont), LLC
    Inventors: Feng Liu, Prakash Mani, Christian Kaiser, Laurence L. Chen
  • Patent number: 9007055
    Abstract: Provided are a self-pinned spin valve magnetoresistance effect film, a magnetic sensor using the same, and a rotation angle detection device. The self-pinned spin valve magnetoresistance effect film has a strong coupling magnetic field in a pinned layer, a small reduction in the change in resistance, and superior resistance to magnetic fields without reducing the coercive force in a first ferromagnetic layer, which is a pinned layer in the film, even when exposed to a strong external magnetic field. By inserting a non-magnetic layer between a ground layer and a pinned layer to form the spin valve magnetoresistance effect film, the self-pinned spin valve magnetoresistance effect film having superior resistance to magnetic fields, a magnetic sensor using the same, and a rotation angle detection device are obtained.
    Type: Grant
    Filed: August 10, 2009
    Date of Patent: April 14, 2015
    Assignee: Hitachi Metals, Ltd.
    Inventors: Tomoki Ono, Yasunori Abe, Fumio Shirasaki
  • Patent number: 9001473
    Abstract: The embodiments disclosed generally relate to a read head in a magnetic recording head. The read head utilizes a sensor structure having: a pinned magnetic structure recessed from a media facing surface; and a reader gap structure. The reader gap structure has a spacer layer recessed from the media facing surface and disposed on top of the pinned magnetic structure, a recessed first free layer partially recessed from the media facing surface and disposed on top of the barrier layer, a second free layer extending to the media facing surface an disposed on top of the barrier layer, and a cap layer extending to the media facing surface disposed atop the second free layer. The pinned magnetic structure, the spacer, and the first free layer have a common face which is on an angle relative to the media facing surface.
    Type: Grant
    Filed: March 21, 2014
    Date of Patent: April 7, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Zheng Gao, James Mac Freitag, Kuok San Ho, Ching Hwa Tsang, Kochan Ju
  • Patent number: 8988834
    Abstract: A magnetoresistive sensor having employing a Mn containing Huesler alloy for improved magnetoresistive performance in a structure that minimizes corrosion and Mn migration. The sensor can be constructed with a pinned layer structure that includes a lamination of layers of Co2MnX and CoFe, where X is Al, Ge or Si. The Co2MnX can be sandwiched between the layers of CoFe to prevent Mn migration into the spacer/barrier layer. The free layer can also be constructed as a lamination of Co2MnX and CoFe layers, and may also be constructed so that the Co2MnX layer is sandwiched between CoFe layers to prevent Mn migration.
    Type: Grant
    Filed: July 23, 2014
    Date of Patent: March 24, 2015
    Assignee: HGST Netherlands B.V.
    Inventor: Hardayal S. Gill
  • Patent number: 8984741
    Abstract: A method for manufacturing a magnetic read sensor allows for the construction of a very narrow trackwidth sensor while avoiding problems related to mask liftoff and shadowing related process variations across a wafer. The process involves depositing a plurality of sensor layers and forming a first mask structure. The first mask structure has a relatively large opening that encompasses a sensor area and an area adjacent to the sensor area where a hard bias structure can be deposited. A second mask structure is formed over the first mask structure and includes a first portion that is configured to define a sensor dimension and a second portion that is over the first mask structure in the field area.
    Type: Grant
    Filed: April 27, 2012
    Date of Patent: March 24, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Yi Zheng, Guomin Mao, Hicham M. Sougrati, Xiaozhong Dang
  • Publication number: 20150077883
    Abstract: According to an embodiment, a magnetic recording apparatus includes following elements. The spin torque oscillator generates a first oscillating magnetic field. The recording medium unit includes one or more recording medium layers which are stacked, each of the one or more recording medium layers including a recording medium and spin-wave lines each of which generates a second oscillating magnetic field. The write magnetic field source generates a write magnetic field. The controller is configured to control the spin torque oscillator, the spin-wave lines, and the write magnetic field source to simultaneously apply the write magnetic field, and the first and second oscillating magnetic fields to target medium magnetization in the recording medium.
    Type: Application
    Filed: September 11, 2014
    Publication date: March 19, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Kiwamu KUDO, Tazumi NAGASAWA, Hirofumi SUTO, Tao Yang, Koichi MIZUSHIMA, Rie SATO
  • Patent number: 8978240
    Abstract: A CPP-GMR spin valve having a composite spacer layer comprised of at least one metal (M) layer and at least one semiconductor or semi-metal (S) layer is disclosed. The composite spacer may have a M/S, S/M, M/S/M, S/M/S, M/S/M/S/M, or a multilayer (M/S/M)n configuration where n is an integer?1. The pinned layer preferably has an AP2/coupling/AP1 configuration wherein the AP2 portion is a FCC trilayer represented by CoZFe(100-Z)/FeYCo(100-Y)/CoZFe(100-Z) where y is 0 to 60 atomic %, and z is 75 to 100 atomic %. In one embodiment, M is Cu with a thickness from 0.5 to 50 Angstroms and S is ZnO with a thickness of 1 to 50 Angstroms. The S layer may be doped with one or more elements. The dR/R ratio of the spin valve is increased to 10% or greater while maintaining acceptable EM and RA performance.
    Type: Grant
    Filed: September 15, 2011
    Date of Patent: March 17, 2015
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Moris Dovek, Yue Liu
  • Patent number: 8976493
    Abstract: A magnetic sensor having improved pinned layer robustness for improved reliability and having improved side shielding for improved track resolution at very high data densities. The sensor has a pinned layer structure with laterally extending wing portions that become thicker with increasing distance from the air bearing surface and has a side shield structure has a thickness that decreases with increasing distance from the air bearing surface.
    Type: Grant
    Filed: December 11, 2013
    Date of Patent: March 10, 2015
    Assignee: HGST Netherlands B.V.
    Inventors: Hideki Mashima, Tutomu Yasuda, Masashige Sato, Masahiko Hatatani
  • Patent number: 8953286
    Abstract: A magnetoresistive element according to an embodiment includes: a magnetoresistance effect film including: a first and second magnetic films; and an intermediate film disposed between the first and second magnetic films, at least one of the first and second magnetic films being formed of a Heusler alloy expressed as Co100-x(AyB1.0-y)x (40 at %?x?60 at %, 0.3?y?0.7) where A is an alloy containing at least Fe and Mn, and B is an alloy containing at least Si, Al, and Ge, a composition of the at least one of the first and second magnetic films being changed in a film-thickness direction so that a ratio of Fe/(Fe+Mn) is less than 60% in a first region disposed near an interface with the intermediate film in the film-thickness direction, and is 60% or more in a second region that is disposed at more distance from the interface than the first region in the film-thickness direction.
    Type: Grant
    Filed: February 28, 2014
    Date of Patent: February 10, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoki Hase, Masayuki Takagishi, Susumu Hashimoto, Shuichi Murakami, Yousuke Isowaki, Masaki Kado, Hitoshi Iwasaki
  • Patent number: 8941195
    Abstract: In a method for fabricating a semiconductor device, a conductive layer is formed on a substrate, where the substrate has a bottom layer formed thereon. A magnetic tunnel junction layer is formed on the conductive layer. The magnetic tunnel junction layer is patterned using an etching gas containing oxygen. An insulating layer is formed by oxidizing the conductive layer exposed outside the patterned magnetic tunnel junction layer using the etching gas.
    Type: Grant
    Filed: December 23, 2011
    Date of Patent: January 27, 2015
    Assignee: SK Hynix Inc.
    Inventors: Min Suk Lee, Bo Kyoung Jung
  • Patent number: 8921126
    Abstract: A process for manufacturing a TMR sensor is disclosed wherein the blocking temperature of the AFM layer in the TMR sensor has been raised by inserting a magnetic seed layer between the AFM layer and the bottom shield. This gives the device improved thermal stability, including improved SNR and BER.
    Type: Grant
    Filed: January 25, 2013
    Date of Patent: December 30, 2014
    Assignee: Headway Technologies, Inc.
    Inventors: Junjie Quan, Kunliang Zhang, Min Li, Hui-Chuan Wang
  • Patent number: 8920947
    Abstract: Perpendicular magnetic anisotropy and Hc are enhanced in magnetic devices with a Ta/M1/M2 seed layer where M1 is preferably Ti, and M2 is preferably Cu, and including an overlying (Co/Ni)X multilayer (x is 5 to 50) that is deposited with ultra high Ar pressure of >100 sccm to minimize impinging energy that could damage (Co/Ni)X interfaces. In one embodiment, the seed layer is subjected to one or both of a low power plasma treatment and natural oxidation process to form a more uniform interface with the (Co/Ni)X multilayer. Furthermore, an oxygen surfactant layer may be formed at one or more interfaces between adjoining (Co/Ni)X layers in the multilayer stack. Annealing at temperatures between 180° C. and 400° C. also increases Hc but the upper limit depends on whether the magnetic device is MAMR, MRAM, a hard bias structure, or a perpendicular magnetic medium.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: December 30, 2014
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yuchen Zhou
  • Patent number: 8914970
    Abstract: A tunneling magnetoresistive sensor has an extended pinned layer wherein both the MgO spacer layer and the underlying ferromagnetic pinned layer extend beyond the back edge of the ferromagnetic free layer in the stripe height direction and optionally also beyond the side edges of the free layer in the trackwidth direction. A patterned photoresist layer with a back edge is formed on the sensor stack and a methanol (CH3OH)-based reactive ion etching (RIE) removes the unprotected free layer, defining the free layer back edge. The methanol-based RIE terminates at the MgO spacer layer without damaging the underlying reference layer. A second patterned photoresist layer may be deposited and a second methanol-based RIE may be performed if it is desired to have the reference layer also extend beyond the side edges of the free layer in the trackwidth direction.
    Type: Grant
    Filed: April 23, 2013
    Date of Patent: December 23, 2014
    Assignee: HGST Netherlands B.V.
    Inventor: Jordan Asher Katine
  • Patent number: 8917485
    Abstract: A magnetoresistive effect element includes a magnetization fixed layer including a first crystal grain, having a magnetization direction which is fixed substantially in one direction, a spacer layer arranged on the magnetization fixed layer and having an insulating layer and a metal conductor penetrating the insulating layer, and a magnetization free layer including a second crystal grain, arranged on the spacer layer to oppose the metal conductor and having a magnetization direction which changes corresponding to an external magnetic field.
    Type: Grant
    Filed: October 13, 2006
    Date of Patent: December 23, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Yoshinari Kurosaki, Hiromi Yuasa, Yoshihiko Fuji, Hitoshi Iwasaki
  • Patent number: 8907666
    Abstract: A scissor style magnetic sensor having a novel hard bias structure for improved magnetic biasing robustness. The sensor includes a sensor stack that includes first and second magnetic layers separated by a non-magnetic layer such as an electrically insulating barrier layer or an electrically conductive spacer layer. The first and second magnetic layers have magnetizations that are antiparallel coupled, but that are canted in a direction that is neither parallel with nor perpendicular to the air bearing surface by a magnetic bias structure. The magnetic bias structure includes a neck portion extending from the back edge of the sensor stack and having first and second sides that are aligned with first and second sides of the sensor stack. The bias structure also includes a tapered or wedged portion extending backward from the neck portion.
    Type: Grant
    Filed: September 30, 2011
    Date of Patent: December 9, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Quang Le, Simon H. Liao, Shuxia Wang, Guangli Liu, Yongchul Ahn
  • Patent number: 8881378
    Abstract: A method is described to improve performance of a magneto-resistive (MR) sensor under conditions of high areal density. The free layer is partially etched away, the removed material being replaced by a magnetic flux guide structure that reduces the free layer's demagnetization field. This in turn reduces the stripe height of the sensor so that the resolution and the read-back signal are enhanced without increasing noise and instability.
    Type: Grant
    Filed: August 22, 2011
    Date of Patent: November 11, 2014
    Assignee: Headway Technologies, Inc.
    Inventors: Yuchen Zhou, Joe Smyth, Min Li, Glen Garfunkel
  • Patent number: 8867177
    Abstract: A magnetic read sensor having improved robustness to withstand thermal variations resulting from thermal fly height heating. Improved thermal robustness comes as a result of improved pinned layer pinning. The read head includes an AFM layer having an increased thickness to provide a higher blocking temperature. The read head further includes a pinned layer structure that includes a first magnetic layer adjacent to and exchange coupled with the AFM layer. The first layer comprises a Co—Fe layer with an increased Fe content of 20-30 atomic percent. The pinned layer structure also includes a second magnetic layer that is antiparallel coupled with the AP1 layer. The AP2 layer can be a multi-layer structure that includes a layer of CoFe, a layer of Co—Fe—Hf formed on the layer of Co—Fe, a layer of Co—Fe—B formed on the layer of Co—Fe—Hf, and a second layer of Co—Fe formed on the layer of Co—Fe—B.
    Type: Grant
    Filed: October 28, 2010
    Date of Patent: October 21, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Satoru Araki, Hardayal S. Gill, Hiroaki Chihaya, Dustin W. Erickson, Haiwen Xi, Chang Man Park
  • Patent number: 8860159
    Abstract: A spintronic electronic apparatus having a multilayer structure. The apparatus includes a substrate, having disposed in succession upon the substrate; a bottom interface layer; a pinned layer; a tunneling barrier; a free layer; and a top interface layer, wherein the apparatus operates as a non-resonant magnetic tunnel junction in a large amplitude, out-of-plane magnetization precession regime having weakly current dependent, large diode volt-watt sensitivity when external microwave signals that exceed a predetermined threshold current and have a frequency that is lower than a predetermined level excite the magnetization precession.
    Type: Grant
    Filed: October 20, 2011
    Date of Patent: October 14, 2014
    Assignee: The United States of America as represented by the Secretary of the Army
    Inventors: Thomas J. Meitzler, Elena N. Bankowski, Michael Nranian, Ilya N. Krivorotov, Andrei N. Slavin, Vasyl S. Tyberkevych
  • Patent number: 8852760
    Abstract: A boron or boron containing dusting layer such as CoB or FeB is formed along one or both of top and bottom surfaces of a free layer at interfaces with a tunnel barrier layer and capping layer to improve thermal stability while maintaining other magnetic properties of a MTJ stack. Each dusting layer has a thickness from 0.2 to 20 Angstroms and may be used as deposited, or at temperatures up to 400° C. or higher, or following a subsequent anneal at 400° C. or higher. The free layer may be a single layer of CoFe, Co, CoFeB or CoFeNiB, or may include a non-magnetic insertion layer. The resulting MTJ is suitable for STT-MRAM memory elements or spintronic devices. Perpendicular magnetic anisotropy is maintained in the free layer at temperatures up to 400° C. or higher. Ku enhancement is achieved and the retention time of a memory cell for STT-MRAM designs is increased.
    Type: Grant
    Filed: April 17, 2012
    Date of Patent: October 7, 2014
    Assignee: Headway Technologies, Inc.
    Inventors: Yu-Jen Wang, Witold Kula, Ru-Ying Tong, Guenole Jan
  • Publication number: 20140293473
    Abstract: A thin film magnetic head includes a spin valve film that includes a magnetization free layer, a magnetization pinned layer and a non-magnetic spacer layer that is disposed between the magnetization free and pinned layers, and a pair of side layers that are disposed at both sides of the spin valve film in a track width direction and at least in the vicinity of the magnetization free layer and the magnetization pinned layer. Each of the side layers has a bias magnetic field application layer that includes a soft magnetic layer and applies a bias magnetic field in the track width direction to the magnetization free layer, and a gap layer that is positioned between the spin valve film and the bias magnetic field application layer, and the side layers have compression stresses at least in the vicinity of the magnetization pinned layer.
    Type: Application
    Filed: March 29, 2013
    Publication date: October 2, 2014
    Applicant: TDK Corporation
    Inventor: TDK Corporation
  • Patent number: 8822046
    Abstract: A stack having a seed layer structure with a first part having a first cross-track width and a free layer deposited over the seed layer structure and with a second cross-track width, wherein the first cross-track width is greater than the second cross-track width. In one implementation, the seed layer structure further comprises an antiferromagnetic (AFM) layer and a synthetic antiferromagnetic (SAF) layer. In one alternate implementation, the cross-track width of the seed layer structure is substantially equal to the combined cross-track width of the free layer and cross-track width of two permanent magnets.
    Type: Grant
    Filed: April 30, 2012
    Date of Patent: September 2, 2014
    Assignee: Seagate Technology LLC
    Inventors: Eric Walter Singleton, Jae-Young Yi, Konstantin Nikolaev, Victor Boris Sapozhnikov, Stacey Christine Wakeham, Shaun Eric McKinlay
  • Patent number: 8817426
    Abstract: A magnetic read sensor having improved magnetic performance and robustness. The magnetic sensor includes a magnetic free layer and a magnetic pinned layer structure. The magnetic pinned layer structure includes first and second magnetic layers separated from one another by a non-magnetic coupling layer. The second magnetic layer of the magnetic pinned layer structure includes a layer of CoFeBTa, which prevents the diffusion of atoms and also promotes a desired BCC crystalline grain growth. The magnetic free layer structure can also include such a CoFeBTa layer for further prevention of atomic diffusion and further promotion of a desired BCC grain growth.
    Type: Grant
    Filed: October 17, 2011
    Date of Patent: August 26, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Zheng Gao, Yingfan Xu, Hua Ai Zeng
  • Patent number: 8810973
    Abstract: A magnetoresistive sensor having employing a Mn containing Huesler alloy for improved magnetoresistive performance in a structure that minimizes corrosion and Mn migration. The sensor can be constructed with a pinned layer structure that includes a lamination of layers of Co2MnX and CoFe, where X is Al, Ge or Si. The Co2MnX can be sandwiched between the layers of CoFe to prevent Mn migration into the spacer/barrier layer. The free layer can also be constructed as a lamination of Co2MnX and CoFe layers, and may also be constructed so that the Co2MnX layer is sandwiched between CoFe layers to prevent Mn migration.
    Type: Grant
    Filed: May 13, 2008
    Date of Patent: August 19, 2014
    Assignee: HGST Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 8791534
    Abstract: In a perpendicular magnetization domain wall motion MRAM in which the magnetizations of both ends of a magnetization free layer are pinned by magnetization pinned layers, the increase of a write current due to leakage magnetic field from the magnetization pinned layer is prevented. A first displacement is present between a first boundary line and a first vertical line, where a curve portion, which crosses a first magnetization free layer, of an outer circumferential line of a first magnetization pinned layer is the first boundary line, a segment which links a center of a magnetization free region and a center of a first magnetization pinned region is a first segment, and a segment, which is a vertical line of the first segment, and which comes in contact with the first boundary line is the first vertical line.
    Type: Grant
    Filed: June 16, 2011
    Date of Patent: July 29, 2014
    Assignee: NEC Corporation
    Inventors: Shunsuke Fukami, Tetsuhiro Suzuki, Kiyokazu Nagahara, Nobuyuki Ishiwata, Norikazu Ohshima
  • Patent number: 8790798
    Abstract: A magnetoresistive element (and method of fabricating the magnetoresistive element) that includes a free ferromagnetic layer comprising a first reversible magnetization direction directed substantially perpendicular to a film surface, a pinned ferromagnetic layer comprising a second fixed magnetization direction directed substantially perpendicular to the film surface, and a nonmagnetic insulating tunnel barrier layer disposed between the free ferromagnetic layer and the pinned ferromagnetic layer, wherein the free ferromagnetic layer, the tunnel barrier layer, and the pinned ferromagnetic layer have a coherent body-centered cubic (bcc) structure with a (001) plane oriented, and a bidirectional spin-polarized current passing through the coherent structure in a direction perpendicular to the film surface reverses the magnetization direction of the free ferromagnetic layer.
    Type: Grant
    Filed: April 12, 2012
    Date of Patent: July 29, 2014
    Inventor: Alexander Mikhailovich Shukh
  • Patent number: 8766733
    Abstract: A radiofrequency oscillator comprises: a free layer (4), a current injector (6) for injecting spin-polarized current into the free layer, this injector having a spin-polarized current injection face (16) directly in contact with the free layer, a magnetoresistive contact (8) having a measurement face (26) directly in contact with the free layer, in order to form, in combination with the free layer, a tunnel junction for measuring the precession of the magnetization of the free layer, a conducting pad (30) directly in contact with the free layer in order to make an electrical current flow through the injector without passing through the magnetoresistive contact. At least part of the measurement face (26) and part of the injection face (16) are placed facing each other on each side of the free layer (4).
    Type: Grant
    Filed: December 20, 2010
    Date of Patent: July 1, 2014
    Assignees: Commissariat a l'energie atomique et aux energies alternatives, Centre National de la Recherche Scientifique
    Inventors: Marie Claire Cyrille, Bertrand Delaet, Ursula Ebels, Dimitri Houssameddine
  • Patent number: 8760822
    Abstract: A method and system provide a magnetic transducer having an air-bearing surface (ABS). The magnetic transducer includes a first shield, a read sensor, at least one soft magnetic bias structure and a second shield. The read sensor includes a sensor layer, a pinned layer and edge(s). The sensor layer has a first stripe height in a stripe height direction perpendicular to the ABS. The pinned layer has a second stripe height in the stripe height direction. The second stripe height is greater than the first stripe height. The soft magnetic bias structure(s) are adjacent to the edge(s) of the sensor. A portion of the soft magnetic bias structure(s) is further from the ABS than the first stripe height. The read sensor is between the first shield and the second shield. The soft magnetic bias structure(s) extend to the second shield.
    Type: Grant
    Filed: November 28, 2012
    Date of Patent: June 24, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Guanxiong Li, Ming Mao, Chih-Ching Hu
  • Publication number: 20140168824
    Abstract: A magnetic read sensor having an extended pinned layer structure and also having an extended free layer structure. The extended pinned layer structure and extended free layer structure both extend beyond the strip height of the free layer of the sensor to provide improved pinning strength as well as improved free layer biasing reliability and bias field strength.
    Type: Application
    Filed: December 19, 2012
    Publication date: June 19, 2014
    Applicant: HGST NETHERLANDS B.V.
    Inventors: Kochan Ju, Quang Le, Simon H. Liao, Guangli Liu
  • Patent number: 8755152
    Abstract: A method and system for providing a magnetic transducer is described. The method and system include providing a magnetic shield, an insertion layer on the magnetic shield, an antiferromagnetic (AFM) layer, a pinned layer magnetically coupled with the AFM layer, a nonmagnetic spacer layer, and a free layer. The magnetic shield has a texture and a grain size. The insertion layer has a thickness that is sufficiently large that the AFM layer is magnetically decoupled from the magnetic shield and sufficiently small that the AFM layer is structurally coupled with the magnetic shield. The pinned layer resides between the AFM layer and the nonmagnetic spacer layer. The nonmagnetic spacer layer resides between the free layer and the pinned layer.
    Type: Grant
    Filed: September 24, 2008
    Date of Patent: June 17, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Chando Park, Qunwen Leng, Min Zhou, Sangmun Oh, Mahendra Pakala
  • Patent number: 8754717
    Abstract: An oscillator and a method of operating the same are provided, the oscillator may include a free layer, a pinned layer on a first surface of the free layer, and a reference layer on a second surface of the free layer. The free layer may have a variable magnetization direction. The pinned layer may have a pinned magnetization direction. The reference layer may have a magnetization direction non-parallel to the magnetization direction of the pinned layer.
    Type: Grant
    Filed: April 28, 2011
    Date of Patent: June 17, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Sung-chul Lee, Sun-ae Seo, Un-hwan Pi, Kee-won Kim, Kwang-seok Kim
  • Patent number: 8749925
    Abstract: Read elements and associated methods of fabrication are disclosed. During fabrication of the read element, and more particularly, the fabrication of the hard bias magnets, a non-magnetic sacrificial layer is deposited on top of the hard bias material. When a CMP process is subsequently performed, the sacrificial layer is polished instead of the hard bias material. The thicknesses of the hard bias magnets are not affected by the CMP process, but are rather defined by the deposition process of the hard bias material. As a result, the variations in the CMP process will not negatively affect the magnetic properties of the hard bias magnets so that they are able to provide substantially uniform effective magnetic fields to bias the free layer of the magnetoresistance (MR) sensor of the read element.
    Type: Grant
    Filed: December 27, 2007
    Date of Patent: June 10, 2014
    Assignee: HGST Netherlands, B.V.
    Inventors: Ying Hong, Ming Jiang, John Westwood
  • Publication number: 20140153139
    Abstract: According to one embodiment, a method of manufacturing a magnetoresistive element includes a layered structure and a pair of electrodes, the layered structure including a cap layer, a magnetization pinned layer, a magnetization free layer, a spacer layer and a functional layer provided in the magnetization pinned layer, between the magnetization pinned layer and the spacer layer, between the spacer layer and the magnetization free layer, in the magnetization free layer, or between the magnetization free layer and the cap layer and including an oxide, the method including forming a film including a base material of the functional layer, performing an oxidation treatment on the film using a gas containing oxygen in a form of at least one selected from the group consisting of molecule, ion, plasma and radical, and performing a reduction treatment using a reducing gas on the film after the oxidation treatment.
    Type: Application
    Filed: February 10, 2014
    Publication date: June 5, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Akihiko TAKEO, Yoshihiko FUJI, Hiromi YUASA, Michiko HARA, Shuichi MURAKAMI, Hideaki FUKUZAWA
  • Patent number: 8742518
    Abstract: A magnetic tunnel junction device includes a reference magnetic layer and a magnetic free layer including first and second magnetic elements that are magnetically exchange coupled. The magnetic exchange coupling between the first and second magnetic elements is configured to achieve a switching current distribution less than about 200% and a long term thermal stability criterion of greater than about 60 kBT.
    Type: Grant
    Filed: March 31, 2011
    Date of Patent: June 3, 2014
    Assignee: Seagate Technology LLC
    Inventors: Xiaobin Wang, Kaizhong Gao
  • Patent number: 8726491
    Abstract: A dual spin filter that minimizes spin-transfer magnetization switching current (Jc) while achieving a high dR/R in STT-RAM devices is disclosed. The bottom spin valve has a MgO tunnel barrier layer formed with a natural oxidation process to achieve low RA, a CoFe/Ru/CoFeB—CoFe pinned layer, and a CoFeB/FeSiO/CoFeB composite free layer with a middle nanocurrent channel (NCC) layer to minimize Jc0. The NCC layer may have be a composite wherein conductive M(Si) grains are magnetically coupled with adjacent ferromagnetic layers and are formed in an oxide, nitride, or oxynitride insulator matrix. The upper spin valve has a Cu spacer to lower the free layer damping constant. A high annealing temperature of 360° C. is used to increase the MR ratio above 100%. A Jc0 of less than 1×106 A/cm2 is expected based on quasistatic measurements of a MTJ with a similar MgO tunnel barrier and composite free layer.
    Type: Grant
    Filed: November 4, 2011
    Date of Patent: May 20, 2014
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Patent number: 8722211
    Abstract: A magnetic memory device may include a first ferromagnetic layer, a second ferromagnetic layer, and a tunnel barrier layer arranged on a substrate. The tunnel barrier layer may include a crystal structure and may be arranged between the first ferromagnetic layer and the second ferromagnetic layer. At least the first ferromagnetic layer may include a first layer in contact with the tunnel barrier layer and a second layer in contact with the first layer, and an orientation of the first layer with respect to the tunnel barrier layer may be greater than an orientation of the second layer with respect to the tunnel barrier layer.
    Type: Grant
    Filed: January 19, 2010
    Date of Patent: May 13, 2014
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Woojin Kim, Jangeun Lee, Sechung Oh, KyungTae Nam, Dae Kyom Kim, Junho Jeong
  • Patent number: 8711528
    Abstract: A tunnel magnetoresistance (TMR) read sensor having a tabbed AFM layer and an extended pinned layer and methods for making the same are provided. The TMR read sensor has an AFM layer recessed from the air bearing surface, providing a reduced shield-to-shield distance.
    Type: Grant
    Filed: June 29, 2012
    Date of Patent: April 29, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Rongfu Xiao, Guanxiong Li, Zhihong Zhang, Ming Mao, Chen-Jung Chien
  • Patent number: 8677607
    Abstract: The method according to the present invention includes the steps of: sequentially applying a plurality of different voltages to an MR element and sequentially detecting output signals from the MR element; and eliminating the MR element as a defective product when an evaluation value, based on a difference of SN ratios of the output signals from the MR element respectively obtained for each applied voltage, is less than a threshold value, and selecting the MR element as a non-defective product when the evaluation value is greater than or equal to the threshold value.
    Type: Grant
    Filed: March 7, 2008
    Date of Patent: March 25, 2014
    Assignee: TDK Corporation
    Inventors: Takumi Yanagisawa, Masaru Hirose, Shunji Saruki
  • Patent number: 8675316
    Abstract: Methods and apparatus provide magnetoresistance sensors. A tunneling magnetoresistance (TMR) sensor may include configurations that are arranged as a top TMR stack. One of two antiparallel layers of pinned layers within the TMR stack may be subdivided by a spacer layer. Tantalum may form the spacer layer that is inserted in a reference layer, which is one of the pinned layers and is located between a barrier layer and an antiparallel coupling layer that enables antiparallel coupling between the reference layer and a keeper layer of the pinned layers. The barrier layer deposited on a free layer of the TMR stacks separates the pinned layers from the free layer such that TMR effects are detectable with the sensors.
    Type: Grant
    Filed: April 11, 2008
    Date of Patent: March 18, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Wen-yaung Lee, Daniele Mauri, Alexander M. Zeltser
  • Patent number: 8675319
    Abstract: In some embodiments, a current perpendicular to the plane giant magneto-resistance (CPP GMR) read sensor may include a reference layer and/or a free layer that includes a plurality of sub-layers. For example, at least one of the reference layer or free layer may include a first ferromagnetic sub-layer, a second ferromagnetic sub-layer, and a Heusler alloy layer located between the first ferromagnetic sub-layer and the second ferromagnetic sub-layer. In some embodiments, a CPP GMR read sensor may include a current closed path (CCP) spacer layer between the reference layer and the free layer. The CCP spacer layer may include Ag and Al2O3. In further embodiments, a CPP GMR read sensor may include a Heusler alloy free layer, a Heusler alloy reference layer, and a CCP spacer layer.
    Type: Grant
    Filed: July 24, 2012
    Date of Patent: March 18, 2014
    Assignee: Seagate Technology LLC
    Inventors: Qing He, Konstantin Nikolaev, Hao Meng, Yonghua Chen, Juren Ding
  • Patent number: 8675318
    Abstract: A method and system for providing a read magnetic transducer having an air-bearing surface (ABS) is described. The magnetic read transducer includes a first shield, a read sensor stack, an antiferromagnetic (AFM) tab, and a second shield. The read sensor stack includes a pinned layer, a spacer layer, and a free layer. The spacer layer is nonmagnetic and between the pinned layer and the free layer. A portion of the read sensor stack is at the ABS. The AFM tab is recessed from the ABS and adjacent to a portion of the pinned layer. The read sensor resides between the first shield and the second shield.
    Type: Grant
    Filed: November 22, 2011
    Date of Patent: March 18, 2014
    Assignee: Western Digital (Fremont), LLC
    Inventors: Kuok San Ho, Savas Gider, Daniele Mauri, Ming Mao, Sining Mao
  • Patent number: 8671554
    Abstract: An example method for manufacturing a magneto-resistance effect element having a magnetic layer, a free magnetization layer, and a spacer layer includes forming a first metallic layer and forming, on the first metallic layer, a second metallic layer. A first conversion treatment is performed to convert the second metallic layer into a first insulating layer and to form a first metallic portion penetrating through the first insulating layer. A third metallic layer is formed on the first insulating layer and the first metallic portion. A second conversion treatment is performed to convert the third metallic layer into a second insulating layer and to form a second metallic portion penetrating through the second insulating layer.
    Type: Grant
    Filed: March 13, 2012
    Date of Patent: March 18, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Yoshihiko Fuji
  • Patent number: 8675317
    Abstract: A current-perpendicular-to-plane (CPP) tunneling magnetoresistance (TMR) or giant magnetoresistance (GMR) read sensor with dual seed and cap layers for high-resolution magnetic recording is provided by the invention. The dual seed layers comprise a lower seed layer preferably formed of a nonmagnetic Pt film and an upper seed layer preferably formed of a nonmagnetic Ru film. The lower seed layer separates the upper seed layer from a buffer layer preferably formed of a ferromagnetic Co—Hf film, in order to minimize moment losses at its lower interface and thus define a sharp lower bound of a read gap. In addition, the lower seed layer facilitates the CPP read sensor to exhibit high pinning properties, while the upper seed layer facilitates the CPP read sensor to exhibit robust thermal properties.
    Type: Grant
    Filed: December 22, 2010
    Date of Patent: March 18, 2014
    Assignee: HGST Netherlands B.V.
    Inventor: Tsann Lin
  • Patent number: 8670216
    Abstract: A current-perpendicular-to-the-plane (CPP) magnetoresistive (MR) sensor has a reference layer formed as an exchange-coupled structure. The exchange-coupled structure includes a patterned layer formed of alternating stripes of ferromagnetic stripes and nonmagnetic stripes, and a continuous unpatterned ferromagnetic layer in contact with and exchange-coupled to the ferromagnetic stripes of the patterned layer. The ferromagnetic stripes have a length-to-width aspect ratio of at least 2, which results in increased uniaxial anisotropy of the exchange-coupled ferromagnetic layer.
    Type: Grant
    Filed: February 11, 2013
    Date of Patent: March 11, 2014
    Assignee: HGST Netherlands B.V.
    Inventors: Patrick Mesquita Braganca, Jeffrey R. Childress, Yang Li, Neil Smith