Having One Film Pinned (e.g., Spin Valve) Patents (Class 360/324.1)
  • Patent number: 7522390
    Abstract: A spin-valve magnetoresistive effect film includes a magnetization fixed layer, a magnetization free layer, and an intermediate layer interposed therebetween. The intermediate layer has a conduction part disposed in an insulation layer and made of a magnetic metal material. The ferromagnetic film stacked on an upper side of the intermediate layer, out of ferromagnetic films constituting the magnetization fixed layer and the magnetization free layer has a perpendicular orientation part which is disposed above the conduction part and whose crystal growth direction is substantially perpendicular to a film plane, and a non-perpendicular orientation part which exists in a portion other than the perpendicular orientation part. A magnetoresistive effect element has a pair of electrodes passing a sense current in a direction perpendicular to the film plane of the magnetoresistive effect film.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: April 21, 2009
    Assignees: Kabushiki Kaisha Toshiba, TDK Corporation
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Hitoshi Iwasaki
  • Publication number: 20090097168
    Abstract: A magnetic thin film being ferromagnetic and exhibiting large spin polarization at room temperature is provided that comprises a substrate (2) and a CO2Fe(Si1-xAlx) thin film (3) formed on the substrate (2) where 0<x<1 and wherein the CO2Fe(Si1-xAlx) thin film (3) has a L21 or a B2 structure. There may be interposed a buffer layer (4) between the substrate (2) and the Co2Fe(Si1-xAlx) thin film (3). A tunneling magnetoresistance effect device and giant magnetoresistance effect device using such a magnetic thin film exhibit large TMR and GMR at room temperature, with low electric current and under low magnetic field. Using such a magnetoresistance effect device, a magnetic device and a magnetic apparatus such as a magnetic sensor, a magnetic head or MRAM are provided.
    Type: Application
    Filed: April 27, 2007
    Publication date: April 16, 2009
    Inventors: Kouichiro Inomata, Nobuki Tezuka
  • Patent number: 7518834
    Abstract: For control of crystal grain size in a spin-valve film, a lithographic technique is needed which exhibits high productivity and enabling formation of a pattern at about 10 nm. In one embodiment of the invention, a diblock copolymer comprising polystyrene (PS) and polymethyl methacrylate (PMMA) is applied to a lower gap layer. When a liquid agent formed by mixing PS and PMMA is coated, a film structure comprising a sea-like PS tissue portion and an island-like PMMA tissue portion is obtained. By applying an ozone RIE treatment to the film structure, the sea-like PS tissue portion is etched to form a pattern of the island-like PMMA tissue portion. The lower gap layer is etched by using the island-like PMMA tissue portion as a resist, then the resist is removed, and an unevenness pattern arranged regularly on the lower gap layer can be formed. A spin-valve film is formed on the lower gap layer subjected to the unevenness fabrication.
    Type: Grant
    Filed: January 25, 2006
    Date of Patent: April 14, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Satoshi Shigematsu
  • Patent number: 7514117
    Abstract: The present invention relates to a method for manufacturing a magnetoresistive element having a magnetization pinned layer, a magnetization free layer, and a spacer layer including an insulating layer provided between the magnetization pinned layer and the magnetization free layer and current paths penetrating into the insulating layer. A process of forming the spacer layer in the method includes depositing a first metal layer forming the metal paths, depositing a second metal layer on the first metal layer, performing a pretreatment of irradiating the second metal layer with an ion beam or a RF plasma of a rare gas, and converting the second metal layer into the insulating layer by means of supplying an oxidation gas or a nitriding gas.
    Type: Grant
    Filed: August 9, 2005
    Date of Patent: April 7, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Katsuhiko Koui, Hiromi Yuasa, Susumu Hashimoto, Hitoshi Iwasaki
  • Patent number: 7515387
    Abstract: A spin-valve magnetoresistive effect film includes a magnetization fixed layer, a magnetization free layer, and a nonmagnetic intermediate layer interposed therebetween. The nonmagnetic intermediate layer has a conduction part disposed in an insulation layer and made of a nonmagnetic metal material. The ferromagnetic film stacked on an upper side of the nonmagnetic intermediate layer, out of ferromagnetic films constituting the magnetization fixed layer and the magnetization free layer has a perpendicular orientation part which is disposed above the conduction part and whose crystal growth direction is substantially perpendicular to a film plane, and a non-perpendicular orientation part which exists in a portion other than the perpendicular orientation part. A magnetoresistive effect element has a pair of electrodes passing a sense current in a direction perpendicular to the film plane of the spin-valve magnetoresistive effect film.
    Type: Grant
    Filed: October 13, 2005
    Date of Patent: April 7, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Hitoshi Iwasaki
  • Patent number: 7511927
    Abstract: A spin valve type magnetoresistive effect element for vertical electric conduction includes a magnetoresistive effect film in which a resistance adjustment layer made of a material containing conductive carriers not more than 1022/cm3 is inserted. Thus the resistance value of a portion in change of spin-relied conduction is raised to an adequate value, thereby to increase the resistance variable amount.
    Type: Grant
    Filed: November 21, 2005
    Date of Patent: March 31, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Masashi Sahashi
  • Publication number: 20090080122
    Abstract: A magnetoresisive sensor having a thin seed layer that provides an exceptionally smooth interface between layers of the sensor stack. The exceptionally smooth interface provided by the seed layer reduces interlayer exchange coupling allowing the non-magnetic spacer layer (or barrier layer) to be very thin. The seed layer includes a thin layer of Ru and a thin layer of Si which intermix to form a homogeneous, amorphous thin seed layer of Ru-silicide.
    Type: Application
    Filed: September 26, 2007
    Publication date: March 26, 2009
    Inventors: James Mac Freitag, Hardayal Singh Gill, Mustafa Michael Pinarbasi
  • Patent number: 7508042
    Abstract: The addition of segmented write word lines to a spin-transfer MRAM structure serves to magnetically bias the free layer so that the precessional motion of the magnetization vector that is set in play by the flow of spin polarized electrons into the free layer allows said magnetic vector to be switched rather than to oscillate between two easy axis directions.
    Type: Grant
    Filed: December 22, 2006
    Date of Patent: March 24, 2009
    Assignee: MagIC Technologies, Inc.
    Inventor: Yimin Guo
  • Patent number: 7505234
    Abstract: A magnetoresistance effect element comprises a magnetoresistance effect film and a pair of electrode. The magnetoresistance effect film having a first magnetic layer whose direction of magnetization is substantially pinned in one direction; a second magnetic layer whose direction of magnetization changes in response to an external magnetic field; a nonmagnetic intermediate layer located between the first and second magnetic layers; and a film provided in the first magnetic layer, in the second magnetic layer, at a interface between the first magnetic layer and the nonmagnetic intermediate layer, and/or at a interface between the second magnetic layer and the nonmagnetic intermediate layer, the film having a thickness not larger than 3 nanometers, and the film has as least one selected from the group consisting of oxide, nitride, oxinitride, phosphide, and fluoride.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: March 17, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Hiromi Fuke, Hitoshi Iwasaki, Masashi Sahashi
  • Patent number: 7502208
    Abstract: A giant magneto-resistive effect element includes a lamination layer structure portion (10) in which at least a free layer (4) the magnetization of which is rotated in response to an external magnetic field, a fixed layer (2), an antiferromagnetic layer (1) for fixing the magnetization of the fixed layer (2) and a nonmagnetic layer (3) interposed between the free layer (4) and the fixed layer (2) are laminated with each other. A sense current flows to substantially a lamination layer direction of the lamination layer structure portion (10) and the lamination layer structure portion (10) has disposed thereon a high-resistance layer (R) which crosses a path of the sense current, whereby an element resistance can be increased and a magneto-resistance change amount can be increased. Thus, a magneto-resistive effect element, a magneto-resistive effect type magnetic sensor, a magneto-resistive effect type magnetic head and a magnetic memory become able to increase a magneto-resistive change amount.
    Type: Grant
    Filed: May 12, 2005
    Date of Patent: March 10, 2009
    Assignee: Sony Corporation
    Inventor: Masanori Hosomi
  • Patent number: 7500303
    Abstract: A read head for a disk drive and a method of fabricating the read head with overlaid lead pads that contact the top surface of the sensor between the hardbias structures to define the electrically active region of the sensor are described. The invention deposits the GMR and lead layers before milling away the unwanted material. A photoresist mask with a hole defining the active area of the sensor is preferably patterned over a layer of DLC that is formed into a mask. A selected portion of the exposed lead material is then removed using the DLC as a mask defining the active region of the sensor. A photoresist mask pad is patterned to define the full sensor width. The excess sensor and lead material exposed around the mask is milled away. The layers for the hardbias structure are deposited.
    Type: Grant
    Filed: May 19, 2006
    Date of Patent: March 10, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Tsung Yuan Chen, Kuok San Ho, Mustafa Michael Pinarbasi
  • Patent number: 7497007
    Abstract: A high performance TMR element is fabricated by inserting an oxygen surfactant layer (OSL) between a pinned layer and AlOx tunnel barrier layer in a bottom spin valve configuration. The pinned layer preferably has a SyAP configuration with an outer pinned layer, a Ru coupling layer, and an inner pinned layer comprised of CoFeXBY/CoFeZ wherein x=0 to 70 atomic %, y=0 to 30 atomic %, and z=0 to 100 atomic %. The OSL is formed by treating the CoFez layer with oxygen plasma. The AlOx tunnel barrier has improved uniformity of about 2% across a 6 inch wafer and can be formed from an Al layer as thin as 5 Angstroms. As a result, the Hin value can be decreased by ? to about 32 Oe. A dR/R of 25% and a RA of 3 ohm-cm2 have been achieved for TMR read head applications.
    Type: Grant
    Filed: July 14, 2005
    Date of Patent: March 3, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Hui-Chuan Wang, Tong Zhao, Min Li, Kunliang Zhang
  • Patent number: 7494724
    Abstract: A method of manufacturing a magnetoresistance effect element includes forming an insulating layer on a first ferromagnetic layer, forming an aperture reaching the first ferromagnetic layer by thrusting a needle from the top surface of the insulating layer, and depositing a ferromagnetic material to form a second ferromagnetic layer overlying the insulating layer which buries the aperture. The aperture can have an opening width not larger than 20 nm. A current flowing between the first ferromagnetic layer and the needle can be monitored, and thrusting of the needle an be interrupted when the current reaches a predetermined value.
    Type: Grant
    Filed: July 3, 2007
    Date of Patent: February 24, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shiho Okuno, Yuichi Ohsawa, Shigeru Haneda, Yuzo Kamiguchi, Tatsuya Kishi
  • Publication number: 20090040661
    Abstract: An insulating barrier layer including a lower insulating layer composed of Al—O and an upper insulating layer composed of CoFe—O and disposed on the lower insulating layer is formed on a second pinned magnetic layer. A free magnetic layer is formed on the insulating barrier layer. According to this structure, a high rate of change in resistance (?R/R) and a low RA (element resistance R×element area A) can be achieved.
    Type: Application
    Filed: October 22, 2008
    Publication date: February 12, 2009
    Applicant: ALPS ELECTRIC CO., LTD.
    Inventors: Kenichi Tanaka, Eiji Umetsu, Kazuaki Ikarashi
  • Publication number: 20090021869
    Abstract: There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, a resistance regulating layer is provided in at least one of a pinned layer, a free layer and an non-magnetic intermediate layer. The resistance regulating layer contains, as a principal component, an oxide, a nitride, a fluoride, a carbide or a boride. The resistance regulating layer may be a continuous film or may have pin holes. Thus, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.
    Type: Application
    Filed: September 17, 2008
    Publication date: January 22, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuuzo KAMIGUCHI, Hiromi YUASA, Tomohiko NAGATA, Hiroaki YODA, Katsuhiko KOUI, Masatoshi YOSHIKAWA, Hitoshi IWASAKI, Masashi SAHASHI, Masayuki TAKAGISHI
  • Publication number: 20090015971
    Abstract: Embodiments of the present invention are directed toward the field of spintronics, and in particular, systems and devices capable of performing spin coherent quantum logic operations. The inventive spin valve comprises two ferromagnetic electrode layers, and a non-magnetic conducting layer positioned therebetween. An external magnetic field B0 is applied in the Z direction, such that the two electrode layers are each magnetized in a direction substantially parallel to the external magnetic field. Rather than attempting to change the magnetization of one of the ferromagnetic layers, as is the case in prior art technologies, it is the direction of the electron spin that is manipulated in the present embodiments while the electron is traveling through the middle, nonmagnetic layer. One of the ferromagnetic electrodes may be the tip of a scanning tunneling microscope (STM).
    Type: Application
    Filed: September 23, 2008
    Publication date: January 15, 2009
    Applicant: INTEMATIX CORPORATION
    Inventors: Haitao Yang, Xiao-Dong Xiang
  • Patent number: 7477491
    Abstract: It has been found that the insertion of a copper laminate within CoFe, or a CoFe/NiFe composite, leads to higher values of CPP GMR and DRA. However, this type of structure exhibits very negative magnetostriction, in the range of high ?10?6 to ?10?5. This problem has been overcome by giving the copper laminates an oxygen exposure treatment When this is done, the free layer is found to have a very low positive magnetostriction constant. Additionally, the value of the magnetostriction constant can be adjusted by varying the thickness of the free layer and/or the position and number of the oxygen treated copper laminates.
    Type: Grant
    Filed: November 7, 2005
    Date of Patent: January 13, 2009
    Assignee: Headway Technologies, Inc.
    Inventors: Min Li, Kunliang Zhang, Masashi Sano, Koichi Terunuma, Simon Liao, Kochan Ju
  • Patent number: 7477490
    Abstract: A differentiated sensor includes a pair of magnetic layers having magnetization directions that are substantially antiparallel in a quiescent state. At least one of the magnetic layers is a free layer. A spacer layer is disposed between the pair of magnetic layers.
    Type: Grant
    Filed: June 30, 2004
    Date of Patent: January 13, 2009
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Jian X. Shen, Shaoping Li, Song S. Xue, Juan J. Fernandez-de-Castro
  • Patent number: 7475471
    Abstract: A GMR read head for a magnetic head, in which the hard bias layers are fabricated immediately next to the side edges of the free magnetic layer, and such that the midplane of the hard bias layer and the midplane of the free magnetic layer are approximately coplanar. The positioning of the hard bias layer is achieved by depositing a thick hard bias seedlayer, followed by an ion milling step is to remove seed layer sidewall deposits. Thereafter, the hard bias layer is deposited on top of the thick seed layer. Alternatively, a first portion of the hard bias seed layer is deposited, followed by an ion milling step to remove sidewall deposits. A thin second portion of the seed layer is next deposited, and the hard bias layer is then deposited.
    Type: Grant
    Filed: November 13, 2006
    Date of Patent: January 13, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Mustafa Michael Pinarbasi
  • Patent number: 7472469
    Abstract: A method is disclosed for fabricating a read sensor for a magnetic head for a hard disk drive having a read sensor stack and two lateral stacks. The method of fabrication includes forming lateral stacks on a gap layer, surrounding a groove to form a template. The read sensor stack is then formed in the groove, which defines the lateral dimensions of the read sensor stack, and lead layers are then formed on the lateral stacks. Also disclosed is a read head for a disk drive having a sensor stack defined by pre-established lateral stacks, and a disk drive having the read head.
    Type: Grant
    Filed: September 20, 2005
    Date of Patent: January 6, 2009
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: David Eugene Heim, Kim Y. Lee, Tsann Lin, Jih-Shiuan Luo, Chun-Ming Wang
  • Publication number: 20090002898
    Abstract: A TMR sensor structure having free and reference layers, where the magnetic orientations of the free and reference layers are non-orthogonal. In one embodiment, a ferromagnetic free layer film has a bias-point magnetization nominally oriented in plane of the film thereof, in a first direction at an angle ?fb with respect to a longitudinal axis being defined as the intersection of the plane of deposition of the free layer and the plane of the ABS. A ferromagnetic reference layer film has a bias-point magnetization nominally oriented in a plane of the film thereof, in a second direction at angle ?rb with respect to said longitudinal axis that is not orthogonal to the said first direction.
    Type: Application
    Filed: July 14, 2008
    Publication date: January 1, 2009
    Inventors: Jeffrey Robinson Childress, Neil Smith
  • Patent number: 7471492
    Abstract: A magnetoresistive element has a first magnetic layer and a second magnetic layer separate from each other, the first magnetic layer and the second magnetic layer each having a magnetization whose direction is substantially pinned, and a non-magnetic conductive layer formed in contact with the first magnetic layer and the second magnetic layer and electrically connecting the first and second magnetic layers, the non-magnetic conductive layer forming a path of spin-polarized electrons from one of the magnetic layer to the other magnetic layer, the non-magnetic conductive layer comprising a portion located between the first magnetic layer and the second magnetic layer, the portion being a sensing area.
    Type: Grant
    Filed: July 22, 2004
    Date of Patent: December 30, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Hiromi Yuasa, Susumu Hashimoto, Hitoshi Iwasaki
  • Patent number: 7471491
    Abstract: A magnetic sensor includes a magnetoresistance element having a peak of a thermal fluctuation strength of magnetization under a magnetic field having a certain frequency, a frequency filter connected to the magnetoresistance element and having its transmittance decreased or increased in substantially the frequency of the magnetic field to output a signal corresponding substantially to the peak of the thermal fluctuation strength of magnetization, and a detector connected to the frequency filter to detect the magnetic field based on the signal of the frequency filter.
    Type: Grant
    Filed: March 24, 2005
    Date of Patent: December 30, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Rie Sato, Koichi Mizushima
  • Publication number: 20080316655
    Abstract: Provided is a current sensor capable of detecting an induced magnetic field by a current to be detected with higher precision. The first and second modules are provided on facing surfaces of integrated substrates, respectively, with spacers in between. Each of the first and second modules includes an element substrate, and an MR element layer. On each of the MR elements layers, provided is an MR element having a stacked structure including a pinned layer, a nonmagnetic intermediate layer, and a free layer whose magnetization direction changes according to the induced magnetic field and which exhibits an anisotropic field in a direction different from that of the magnetization of the pinned layer. The stacked structures of the MR elements are provided in a same layer level.
    Type: Application
    Filed: June 18, 2008
    Publication date: December 25, 2008
    Applicant: TDK CORPORATION
    Inventor: Shigeru Shoji
  • Patent number: 7466523
    Abstract: Present invention discloses novel designs of carbon nanotube spin valve structures for incorporation into magnetic storage and magnetic sensing devices, such as magnetic read head, MRAM, and magnetic field sensor. One of the designs is an in-stack carbon nanotube spin valve, which consists of a ferromagnetic free layer and a ferromagnetic pinned layer. The two layers are physically separated, although they reside in parallel planes. A single or plurality of vertically aligned carbon nanotubes are in between the two layers, and in electrical contact with both. The other design is a planar carbon nanotube spin valve, which consists of ferromagnetic free layer and pinned layer in substantially the same plane. They are electrically connected by in-plane aligned carbon nanotubes, which reside in between. The methods of fabricating the magnetic read head and MRAM devices utilizing these types of carbon nanotube spin valves are also described.
    Type: Grant
    Filed: July 10, 2003
    Date of Patent: December 16, 2008
    Inventor: Yingjian Chen
  • Publication number: 20080304176
    Abstract: A magnetic recording head includes a recording magnetic pole, and a spin oscillation device including a first magnetic layer having at least one magnetic material layer, a second magnetic layer having at least one magnetic material layer, and a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer. The first magnetic layer and the second magnetic layer are antiferromagnetically coupled and/or magnetostatically coupled to each other. The first magnetic layer and the second magnetic layer are laminated in a direction generally parallel to a medium facing surface and generally parallel to a side surface of the recording magnetic pole intersecting with the medium facing surface.
    Type: Application
    Filed: June 4, 2008
    Publication date: December 11, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masayuki Takagishi, Kenichiro Yamada, Hitoshi Iwasaki, Junichi Akiyama, Tomomi Funayama, Masahiro Takashita, Mariko Shimizu
  • Patent number: 7459759
    Abstract: A magnetic random access memory described in embodiments of the present invention comprises a conductive line, a soft magnetic material which surrounds the conductive line, a gap disposed in a part of the soft magnetic material, and a magneto-resistive element in which a part of a vertical magnetization film as a magnetic free layer is positioned in the gap and in which a vertical magnetization film as a magnetic pinned layer is positioned outside the gap.
    Type: Grant
    Filed: June 6, 2006
    Date of Patent: December 2, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yoshiaki Fukuzumi, Toshihiko Nagase
  • Publication number: 20080285181
    Abstract: A method for providing a giant magneto-resistive (GMR) sensor for use in sensing magnetic flux is provided. The method comprises positioning a layer of Cu material between first and second layers of a specified ferromagnetic material. The respective end surfaces of the Cu layer and the first and second layers are initially located in a common plane and in a co-planar relationship with one another. The method further comprises removing an amount of material from the copper layer to form a new end surface thereof that is selectively spaced apart from the common plane and applying a protective coating to the new end surface of the Cu layer to inhibit corrosion of the Cu layer.
    Type: Application
    Filed: June 5, 2008
    Publication date: November 20, 2008
    Applicant: STORAGE TECHNOLOGY CORPORATION
    Inventors: John P. Nibarger, Herbert House
  • Patent number: 7453672
    Abstract: A magnetoresistive device with a spin valve formed from a stack of layers including at least two magnetic layers for which the relative orientation of their magnetization directions can vary under the influence of a magnetic field, and comprising means of circulating a current in the spin valve transverse to the plane of the layers. The spin valve comprises at least one discontinuous dielectric or semiconducting layer in the stack, with electrically conducting bridges passing through the thickness of the dielectric or semiconducting layer, these bridges being designed to locally concentrate the current that passes transversely through the stack. Application particularly suitable for magnetic read heads, and random access memories.
    Type: Grant
    Filed: October 10, 2002
    Date of Patent: November 18, 2008
    Assignee: Commissariat a l'Energie Atomique
    Inventors: Bernard Dieny, Bernard Rodmacq, Franck Ernult
  • Patent number: 7443004
    Abstract: In a spin valve type element, an interface insertion layer (32, 34) of a material exhibiting large spin-dependent interface scattering is inserted in a location of a magnetically pinned layer (16) or a magnetically free layer (20) closer to a nonmagnetic intermediate layer (18). A nonmagnetic back layer (36) may be additionally inserted as an interface not in contact with the nonmagnetic intermediate layer to increase the output by making use of spin-dependent interface scattering along the interface between the pinned layer and the nonmagnetic back layer or between the free layer and the nonmagnetic back layer.
    Type: Grant
    Filed: November 22, 2005
    Date of Patent: October 28, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Yuzo Kamiguchi, Masatoshi Yoshikawa, Katsuhiko Koui, Hitoshi Iwasaki, Tomohiko Nagata, Takeo Sakakubo, Masashi Sahashi
  • Patent number: 7443638
    Abstract: Disclosed herein is a magnetoresistive structure, for example useful as a spin-valve or GMR stack in a magnetic sensor, and a fabrication method thereof. The magnetoresistive structure uses twisted coupling to induce a perpendicular magnetization alignment between the free layer and the pinned layer. Ferromagnetic layers of the free and pinned layers are exchange-coupled using antiferromagnetic layers having substantially parallel exchange-biasing directions. Thus, embodiments can be realized that have antiferromagnetic layers formed of a same material and/or having a same blocking temperature. At least one of the free and pinned layers further includes a second ferromagnetic layer and an insulating layer, such as a NOL, between the two ferromagnetic layers. The insulating layer causes twisted coupling between the two ferromagnetic layers, rotating the magnetization direction of one 90 degrees relative to the magnetization direction of the other.
    Type: Grant
    Filed: April 22, 2005
    Date of Patent: October 28, 2008
    Assignee: Taiwan Semiconductor Manufacturing Company Ltd.
    Inventors: Yu-Jen Wang, Chih-Huang Lai, Wen-Chin Lin, Denny Tang, Chao-Hsiung Wang
  • Patent number: 7443636
    Abstract: Embodiments of the invention implement a construction capable of reconciling high read output with high stability by improving the structures of magnetic films. In one embodiment, an inclined crystal grain structure is applied to a soft magnetic free layer, ferromagnetic pinned layer and so forth, thereby enhancing electron scatter performance of thin magnetic films.
    Type: Grant
    Filed: November 10, 2005
    Date of Patent: October 28, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Katsumi Hoshino, Hiroyuki Hoshiya, Kenichi Meguro, Yasuyuki Okada
  • Patent number: 7443635
    Abstract: A multilayer film is placed on a subatrate. The multilayer film includes an antiferromagnetic layer, a pinned magnetic layer, a non-magnetic material layer, and a free magnetic layer. The multilayer film has recessed sections arranged in both side regions thereof, the recessed sections being formed by partly removing the multilayer film in a vacuum. The bottoms of the recessed sections are located between the upper face and lower face of the antiferromagnetic layer. Amorphous barrier layers with a thickness of ? are placed on the bottoms of the recessed sections, the amorphous barrier layers being formed in the same vacuum as that for forming the recessed sections sequentially to the step of forming the recessed sections.
    Type: Grant
    Filed: October 4, 2005
    Date of Patent: October 28, 2008
    Assignee: Alps Electric Co., Ltd.
    Inventors: Kenichi Tanaka, Eiji Umetsu, Masahiro Oshima, Naoya Hasegawa
  • Publication number: 20080259507
    Abstract: A tunneling magnetoresistive (TMR) sensor with a free layer made of a Co—Fe—B alloy is disclosed. After annealing at a temperature of less than 300° C., the Co—Fe—B free layer exhibits a negative or zero saturation magnetostriction, ?S, while the TMR sensor exhibits superior TMR properties. The Co—Fe—B free layer has an Fe content of not greater than 10 atomic percent, and a B content of not greater than 10 atomic percent. Alternatively, a free-layer structure is used in place of the Co—Fe—B free layer The free-layer structure includes a first free layer lying on a barrier layer and a second free layer lying on the first free layer. The first free layer is made of an alloy selected from Co—Fe, Co—B and Co—Fe—B alloys, while the second free layer is made of an alloy selected from Co—B and Co—Fe—B alloys. The first free layer has an Fe content of not greater than 10 atomic percent, and a B content of not greater than 10 atomic percent.
    Type: Application
    Filed: April 17, 2007
    Publication date: October 23, 2008
    Inventor: Tsann Lin
  • Patent number: 7436636
    Abstract: A dual current perpendicular to plane (CPP) sensor having an in stack bias structure disposed between first and second free layers. The hard bias structure includes a plurality of magnetic layers antiparallel coupled with one another. At least one of the magnetic layers of the in stack bias structure includes a layer of Ni sandwiched between first and second layer of NiFe. The Ni provides a strong negative magnetostriction that sets the moment of the magnetic layer in a desired direction parallel with the ABS while the NiFe layers at either side of the Ni provide good antiparallel coupling properties, allowing the magnetic layer to be antiparallel coupled with adjacent magnetic layers of the in stack bias structure.
    Type: Grant
    Filed: November 10, 2004
    Date of Patent: October 14, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 7433160
    Abstract: A magnetoresistive element is disclosed that includes a magnetoresistive film; a cap film configured to cover the magnetoresistive film and include a three-layer structure in at least a part thereof, the three-layer structure being formed of a third protection layer, a second protection layer, and a first protection layer in order from the magnetoresistive film side; and upper and lower terminals for applying a sense current perpendicularly to the surface of the magnetoresistive film. The magnetoresistive film includes a first magnetic layer whose direction of magnetization is changed by an external magnetic field, a second magnetic layer whose direction of magnetization is fixed with respect to the external magnetic field, and a nonmagnetic layer magnetically separating the first magnetic layer and the second magnetic layer.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: October 7, 2008
    Assignee: Fujitsu Limited
    Inventors: Keiichi Nagasaka, Yutaka Shimizu
  • Publication number: 20080239587
    Abstract: A magneto-resistance effect element includes: a first magnetic layer of which a first magnetization is fixed in one direction; a second magnetic layer of which a second magnetization is fixed in one direction; a spacer layer located between the first magnetic layer and the second magnetic layer and made of at least one selected from the group consisting of an oxide, a nitride, an oxynitride and a metal; and a current bias generating portion, which is located adjacent to the spacer layer, for applying a bias magnetic field to the spacer layer.
    Type: Application
    Filed: March 6, 2008
    Publication date: October 2, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Junichi Ito, Hideaki Fukuzawa, Hiromi Yuasa, Yoshihiro Fuji
  • Publication number: 20080239588
    Abstract: A magneto-resistance effect element includes a magneto-resistance effect film comprised of a free magnetization layer, a fixed magnetization layer and an intermediate layer disposed between the free magnetization layer and the fixed magnetization layer; a magnetic coupling layer which is disposed on one main surface of the fixed magnetization layer; a ferromagnetic layer which is disposed on one main surface of the magnetic coupling layer; an antiferromagnetic layer which is disposed on one main surface of the ferromagnetic layer; a magnetic domain controlling film for applying a biasing magnetic field to the free magnetization layer; and a pair of electrodes for flowing a current in the magneto-resistance effect film; wherein an asymmetry is set positive and an element resistance RA is set to 1.5 ??m2 or less in the direction from the free magnetization layer to the fixed magnetization layer.
    Type: Application
    Filed: March 14, 2008
    Publication date: October 2, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masahiro Takashita, Tomomi Funayama, Masayuki Takagishi, Hitoshi Iwasaki
  • Patent number: 7428127
    Abstract: A CPP magnetoresistive effect element includes a free magnetization layer, a fixed magnetization layer, and a plurality of conductive non-magnetic intermediate layers formed between the free magnetization layer and the fixed magnetization layer. An insulating layer and a magnetic layer including magnetic atoms are provided between any two of the non-magnetic intermediate layers.
    Type: Grant
    Filed: January 25, 2005
    Date of Patent: September 23, 2008
    Assignee: Fujitsu Limited
    Inventors: Keiichi Nagasaka, Yoshihiko Seyama, Hirotaka Oshima, Yutaka Shimizu, Atsushi Tanaka
  • Patent number: 7423847
    Abstract: A current-perpendicular-to-the-plane spin-valve (CPP-SV) magnetoresistive sensor has an insulating layer with at least one aperture that confines the flow of sense current through the active region. The apertures are located closer to the sensing edge of the sensor than to the back edge of the sensor. The aperture (or apertures) are patterned by e-beam lithography, which enables the number, size and location of the apertures to be precisely controlled. The insulating layer may be located inside the electrically conductive nonmagnetic spacer layer, or outside of the magnetically active layers of the spin-valve. More than one insulating layer may be included in the stack to define conductive current paths where the apertures of the insulating layers overlap. The apertures are filled with electrically conductive material, typically the same material as that used for the spacer layer.
    Type: Grant
    Filed: November 3, 2005
    Date of Patent: September 9, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Matthew J. Carey, Jeffrey R. Childress, Stefan Maat, Neil Smith
  • Patent number: 7423848
    Abstract: A CPP-GMR spin value sensor structure with an improved MR ratio and increased resistance is disclosed. All layers except certain pinned layers, copper spacers, and a Ta capping layer are oxygen doped by adding a partial O2 pressure to the Ar sputtering gas during deposition. Oxygen doped CoFe free and pinned layers are made slightly thicker to offset a small decrease in magnetic moment caused by the oxygen dopant. Incorporating oxygen in the MnPt AFM layer enhances the exchange bias strength. An insertion layer such as a nano-oxide layer is included in one or more of the free, pinned, and spacer layers to increase interfacial scattering. The thickness of all layers except the copper spacer may be increased to enhance bulk scattering. A CPP-GMR single or dual spin valve of the present invention has up to a threefold increase in resistance and a 2 to 3% increase in MR ratio.
    Type: Grant
    Filed: July 27, 2007
    Date of Patent: September 9, 2008
    Assignee: Headway Technologies, Inc.
    Inventors: Cheng T. Horng, Ru-Ying Tong
  • Publication number: 20080212241
    Abstract: A write head and a method for forming the write head. The method includes providing a first pole and a second pole for the write head. The first pole and the second pole are formed from a ferromagnetic material. Regions of the write head including at least a portion of at least one of the first pole and the second pole of the write head are volumetrically doped with a dopant material selected from one of a 4d transition metal, 5d transition metal, and 4f rare earth metal. The dopant material is predetermined to provide a magnetic damping in the doped regions which is greater than the magnetic damping in the ferromagnetic material.
    Type: Application
    Filed: August 15, 2007
    Publication date: September 4, 2008
    Inventor: MANFRED ERNST SCHABES
  • Patent number: 7420786
    Abstract: An area of an element can be made small and fluctuation in area can be reduced. A magneto-resistance effect element is provided with a first electrode with an end face; a magneto-resistance effect film which is formed such that a surface thereof comes in contact with the end face of the first electrode; and a second electrode which is formed on another surface of the magneto-resistance effect element opposed from the surface coming in contact with the surface of the first electrode. The magneto-resistance effect film includes a magnetization pinned layer whose magnetization direction is pinned, a magnetization free layer whose magnetization direction is changeable, and a first non-magnetic layer which is provided between the magnetization pinned layer and the magnetization free layer.
    Type: Grant
    Filed: March 1, 2005
    Date of Patent: September 2, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideyuki Sugiyama, Yoshiaki Saito
  • Patent number: 7420787
    Abstract: A magnetoresistive sensor having a pinned layer that extends beyond the stripe height defined by the free layer of the sensor. The extended pinned layer has a strong shape induced anisotropy that maintains pinning of the pinned layer moment. The extended portion of the pinned layer has sides beyond the stripe height that are perfectly aligned with the sides of the sensor within the stripe height. This perfect alignment is made possible by a manufacturing method that uses a mask structure for more than one manufacturing phase, eliminating the need for multiple mask alignments.
    Type: Grant
    Filed: August 15, 2005
    Date of Patent: September 2, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: James Mac Freitag, Kuok San Ho, Mustafa Michael Pinarbasi, Ching Hwa Tsang
  • Publication number: 20080204944
    Abstract: It is possible to reduce writing current without causing fluctuation of the writing characteristic. A magnetic memory includes: a magnetoresistance effect element having a magnetization pinned layer whose magnetization direction is pinned, a storage layer whose magnetization direction is changeable, and a non-magnetic layer provided between the magnetization pinned layer and the storage layer; and a first wiring layer which is electrically connected to the magnetoresistance effect element and extends in a direction substantially perpendicular to a direction of an easy magnetization axis of the storage layer, an end face of the magnetoresistance effect element substantially perpendicular to the direction of the easy magnetization axis of the storage layer and an end face of the first wiring layer substantially perpendicular to the direction of the easy magnetization axis being positioned on the same plane.
    Type: Application
    Filed: April 10, 2008
    Publication date: August 28, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Hisanori Aikawa, Tomomasa Ueda, Tatsuya Kishi, Takeshi Kajiyama, Yoshiaki Asao, Hiroaki Yoda
  • Publication number: 20080204943
    Abstract: A magnetoresistive element includes: a first magnetic layer whose magnetization direction is substantially pinned toward one direction; a second magnetic layer whose magnetization direction is changed in response to an external magnetic field; and a spacer layer provided between the first magnetic layer and the second magnetic layer. At least one of the first magnetic layer and the second magnetic layer has a magnetic compound that is expressed by M1aM2bXc (where 5?a?68, 10?b?73, and 22?c?85) M1 is at least one element selected from the group consisting of Co, Fe, and Ni. M2 is at least one element selected from the group consisting of Ti, V, Cr, and Mn. X is at least one element selected from the group consisting of N, O, and C.
    Type: Application
    Filed: September 24, 2007
    Publication date: August 28, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yoshihiko Fuji, Hideaki Fukuzawa, Hiromi Yuasa
  • Publication number: 20080204942
    Abstract: A magnetic thin film has a pinned layer whose magnetization direction is fixed with respect to an external magnetic field, a free layer whose magnetization direction is changed according to the external magnetic field, and a spacer layer which is sandwiched between said pinned layer and said free layer. Sense current is configured to flow in a direction that is perpendicular to film surfaces of said pinned layer, said spacer layer, and said free layer. Said spacer layer has a CuZn metal alloy which includes an oxide region, said oxide region consisting of an oxide of any of Al, Si, Cr, Ti, Hf, Zr, Zn, and Mg.
    Type: Application
    Filed: February 23, 2007
    Publication date: August 28, 2008
    Inventors: Takahiko MACHITA, Tomohito MIZUNO, Yoshihiro TSUCHIYA, Daisuke MIYAUCHI, Shinji HARA
  • Patent number: 7417832
    Abstract: A method and system for providing a magnetoresistive structure is disclosed. The magnetoresistive structure includes a pinned layer, a nonmagnetic spacer layer, a free layer, a filter layer, a specular layer, a barrier layer, and a capping layer. The nonmagnetic spacer layer resides between the pinned layer and the free layer. The free layer is electrically conductive and resides between the filter layer and the nonmagnetic spacer layer. The specular layer includes a first material and is electrically insulating. The barrier layer resides between the specular oxide layer and the capping layer. The barrier layer is nonmagnetic and includes a second material different material from the first material. The capping layer includes a third material different from the second material.
    Type: Grant
    Filed: April 26, 2005
    Date of Patent: August 26, 2008
    Assignee: Western Digital (Fremont), LLC
    Inventors: Dustin W. Erickson, Chang-Man Park, Shin Funada, Lena Miloslavsky
  • Publication number: 20080198514
    Abstract: A CPP-type magnetoresistive device includes a magnetization pinned layer, a magnetization free layer, and a non-magnetic layer provided between the magnetization pinned layer and the magnetization free layer. At least one of the magnetization free layer and the magnetization pinned layer is formed of CoFeGe, and the CoFeGe has a composition falling within a range defined by line segments connecting coordinate points A, B, C, and D in a ternary composition diagram where the point A is (42.5, 30, 27.5), the point B is (35, 52.5, 12.5), the point C is (57.5, 30.0, 12.5), and the point D is (45.0, 27.5, 27.5), and where each of the coordinate points is represented by content percentage of (Co, Fe, Ge) expressed by atomic percent (at. %).
    Type: Application
    Filed: February 13, 2008
    Publication date: August 21, 2008
    Applicant: FUJITSU LIMITED
    Inventors: Arata Jogo, Yutaka Shimizu
  • Patent number: 7411765
    Abstract: A CPP GMR sensor structure having free and reference layers, where the magnetic orientations of the free and reference layers are non-orthogonal. In one embodiment, a ferromagnetic free layer film has a bias-point magnetization nominally oriented in plane of the film thereof, in a first direction at an angle ?fb with respect to a longitudinal axis being defined as the intersection of the plane of deposition of the free layer and the plane of the ABS. A ferromagnetic reference layer film has a bias-point magnetization nominally oriented in a plane of the film thereof, in a second direction at angle ?rb with respect to said longitudinal axis that is not orthogonal to the said first direction.
    Type: Grant
    Filed: July 25, 2005
    Date of Patent: August 12, 2008
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Jeffrey Robinson Childress, Neil Smith