Having Tunnel Junction Effect Patents (Class 360/324.2)
  • Patent number: 8338004
    Abstract: The present invention provides a magnetic tunnel junction structure, including a first magnetic layer having a fixed magnetization direction and a second magnetic layer having a reversible magnetization direction. A non-magnetic layer is formed between the first magnetic layer and the second magnetic layer and a third magnetic layer allows the magnetization direction of the second magnetic layer to be inclined with respect to a plane of the second magnetic layer by a magnetic coupling to the second magnetic layer with a vertical magnetic anisotropic energy thereof larger than a horizontal magnetic anisotropic energy thereof. A crystal-structure separation layer is formed between the second magnetic layer and the third magnetic layer for separating a crystal orientation between the second and the third magnetic layers.
    Type: Grant
    Filed: October 29, 2009
    Date of Patent: December 25, 2012
    Assignee: Korea Institute of Science and Technology
    Inventors: Kyung Ho Shin, Byoung Chul Min
  • Patent number: 8336194
    Abstract: A method of fabricating a tunneling magnetoresistance (TMR) reader is disclosed. A TMR structure comprising at least one ferromagnetic layer and at least one nonmagnetic insulating layer is provided. A first thermal annealing process on the TMR structure is performed. A reader pattern definition process performed on the TMR structure to obtain a patterned TMR reader. A second thermal annealing process is performed on the patterned TMR reader.
    Type: Grant
    Filed: November 3, 2009
    Date of Patent: December 25, 2012
    Assignee: Western Digital (Fremont), LLC
    Inventors: Lu Yuan, Jian X. Shen, Geoffrey W. Anderson, Christopher Ng
  • Patent number: 8339754
    Abstract: An insertion layer is provided between an AFM layer and an AP2 pinned layer in a GMR or TMR element to improve exchange coupling properties by increasing Hex and the Hex/Hc ratio without degrading the MR ratio. The insertion layer may be a 1 to 15 Angstrom thick amorphous magnetic layer comprised of at least one element of Co, Fe, or Ni, and at least one element having an amorphous character selected from B, Zr, Hf, Nb, Ta, Si, or P, or a 1 to 5 Angstrom thick non-magnetic layer comprised of Cu, Ru, Mn, Hf, or Cr. Preferably, the content of the one or more amorphous elements in the amorphous magnetic layer is less than 40 atomic %. Optionally, the insertion layer may be formed within the AP2 pinned layer. Examples of an insertion layer are CoFeB, CoFeZr, CoFeNb, CoFeHf, CoFeNiZr, CoFeNiHf, and CoFeNiNbZr.
    Type: Grant
    Filed: June 30, 2011
    Date of Patent: December 25, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Hui-Chuan Wang, Tong Zhao, Min Li
  • Patent number: 8339752
    Abstract: In one embodiment, a magnetic head includes a magnetoresistive free layer, wherein a width of the free layer nearest an air bearing surface (ABS) is less than a width of the free layer at a point away from the ABS in a track width direction, with the magnetic head being configured to pass a sense current in a direction perpendicular to a plane of deposition of the free layer. In another embodiment, a method includes forming a magnetoresistive film above a shield, forming a masking layer above the magnetoresistive film, patterning the masking layer such that it exposes portions of the magnetoresistive film, wherein the masking layer defines an area which is narrow near an area that forms an ABS side of a free layer and wider at an area away from the ABS, and removing the exposed portions of the magnetoresistive film to form the free layer.
    Type: Grant
    Filed: September 26, 2011
    Date of Patent: December 25, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masashi Hattori, Koichi Nishioka, Koji Sakamoto, Tsutomu Yasuda, Hideki Mashima
  • Patent number: 8335059
    Abstract: A magnetoresistive effect element includes a first ferromagnetic layer, Cr layer, Heusler alloy layer, barrier layer, and second ferromagnetic layer. The first ferromagnetic layer has the body-centered cubic lattice structure. The Cr layer is formed on the first ferromagnetic layer and has the body-centered cubic lattice structure. The Heusler alloy layer is formed on the Cr layer. The barrier layer is formed on the Heusler alloy layer. The second ferromagnetic layer is formed on the barrier layer.
    Type: Grant
    Filed: June 26, 2012
    Date of Patent: December 18, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mizue Ishikawa, Yoshiaki Saito, Hideyuki Sugiyama, Tomoaki Inokuchi
  • Patent number: 8331064
    Abstract: A method in one embodiment includes applying a current to a lead of a tunneling magnetoresistance sensor for inducing joule heating of the lead or a heating layer, the level of joule heating being sufficient to anneal a magnetic layer of the sensor; and maintaining the current at the level for an amount of time sufficient to anneal the tunneling magnetoresistive (TMR) sensor. A system in one embodiment comprises a first lead coupled to one end of a tunneling magnetoresistance sensor stack; a second lead coupled to another end of the sensor stack; and a third lead coupled to the first lead, the third lead being selectively coupleable to a ground, wherein a current applied to the first lead at a predetermined level when the third lead is coupled to the ground induces joule heating of the first lead or a heating layer coupled to the first and third leads, the joule heating applied for a predetermined amount of time being sufficient to anneal a magnetic layer of the sensor.
    Type: Grant
    Filed: April 18, 2008
    Date of Patent: December 11, 2012
    Assignee: International Business Machines Corporation
    Inventor: Icko E. Tim Iben
  • Patent number: 8324696
    Abstract: Provided are an ultrafast magnetic recording element and a nonvolatile magnetic random access memory using the same. The magnetic recording element includes a read electrode, a magnetic pinned layer formed on the read electrode, and an insulating layer or a conductive layer formed on the magnetic pinned layer. The magnetic recording element includes a magnetic free layer formed on the insulating layer or the conductive layer, in which a magnetic vortex is formed, and a plurality of drive electrodes applying a current or magnetic field to the magnetic free layer. According to the magnetic recording elements, the magnetic recording element with a simple structure can be realized using a magnetic layer with a magnetic vortex formed, and the magnetic recording element can be accurately driven with low power using a plurality of drive electrodes.
    Type: Grant
    Filed: October 17, 2008
    Date of Patent: December 4, 2012
    Assignee: SNU R&DB Foundation
    Inventors: Sang-Koog Kim, Ki-Suk Lee, Young-Sang Yu
  • Patent number: 8324697
    Abstract: A magnetic layer that includes a seed layer comprising at least tantalum and a free magnetic layer comprising at least iron. The free magnetic layer is grown on top of the seed layer and the free magnetic layer is perpendicularly magnetized. The magnetic layer may be included in a magnetic tunnel junction (MTJ) stack.
    Type: Grant
    Filed: June 15, 2010
    Date of Patent: December 4, 2012
    Assignee: International Business Machines Corporation
    Inventor: Daniel C. Worledge
  • Patent number: 8325450
    Abstract: A magnetic structure in one embodiment includes a tunnel barrier layer; a free layer; and a buffer layer between the tunnel barrier layer and the free layer, wherein a cross sectional area of the tunnel barrier layer in a direction parallel to a plane of deposition thereof is greater than a cross sectional area of the free layer in a direction parallel to a plane of deposition thereof, wherein a cross sectional area of the buffer layer in a direction parallel to a plane of deposition thereof is greater than a cross sectional area of the free layer in the direction parallel to the plane of deposition thereof. Additional systems and methods are also presented.
    Type: Grant
    Filed: December 10, 2008
    Date of Patent: December 4, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ying Hong, Kochan Ju, Tsann Lin, Ching Hwa Tsang
  • Patent number: 8316527
    Abstract: The method provides a magnetoresistive device. The magnetoresistive device is formed from a plurality of magnetoresistive layers. The method includes providing a mask. The mask covers a first portion of the magnetoresistive element layers in at least one device area. The magnetoresistive element(s) are defined using the mask. The method includes depositing hard bias layer(s). The method also includes providing a hard bias capping structure on the hard bias layer(s). The hard bias capping structure includes a first protective layer and a planarization stop layer. The first protective layer resides between the planarization stop layer and the hard bias layer(s). The method also includes performing a planarization. The planarization stop layer is configured for the planarization.
    Type: Grant
    Filed: April 1, 2008
    Date of Patent: November 27, 2012
    Assignee: Western Digital (Fremont), LLC
    Inventors: Liubo Hong, Honglin Zhu
  • Patent number: 8307539
    Abstract: A method for modeling devices in a wafer comprises the step of providing the wafer comprising a first plurality of devices having a track width and a first stripe height, a second plurality of devices having the track width and a second stripe height, and a third plurality of devices having the track width and a third stripe height. The method further comprises the steps of measuring resistance values for the first, second and third plurality of devices to obtain a data set correlating a stripe height and a resistance value for each of the first, second and third plurality of devices, and estimating a linear relationship between resistance and inverse stripe height for the first, second and third plurality of devices based on the data set.
    Type: Grant
    Filed: September 30, 2009
    Date of Patent: November 13, 2012
    Assignee: Western Digital (Fremont), LLC
    Inventors: Steven C. Rudy, Eric R. Mckie, Mark D. Moravec
  • Patent number: 8305716
    Abstract: An example magneto-resistance effect element includes a magnetization layer and a free magnetization layer of which magnetization direction changes depending on an external magnetic field. A spacer layer is located between the magnetization layer and the free magnetization layer, and has an insulating layer and an electric conductor passing current therethrough in a layer direction of the insulating layer. A diffusive electron scattering layer is disposed on said free magnetization layer for scattering diffusive electrons. The scattering layer includes a first nonmagnetic layer and a second nonmagnetic layer containing a first element and a second element, respectively, and a mixing layer disposed at a boundary between the first and second nonmagnetic layers and containing the first and second elements. The mixing layer has a thickness of 0.5 nm or more and 1.5 nm or less.
    Type: Grant
    Filed: January 27, 2012
    Date of Patent: November 6, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hideaki Fukuzawa, Masahiro Takashita, Hiromi Yuasa, Yoshihiko Fuji, Hitoshi Iwasaki
  • Patent number: 8296930
    Abstract: A method for manufacturing a magnetoresistive sensor that results in the sensor having a very flat top magnetic shield. The process involves depositing a plurality of sensor layers and then depositing a thin high density carbon CMP stop layer over the sensor layers and forming a mask over the CMP stop layer. An ion milling is performed to define the sensor. Then a thin insulating layer and magnetic hard bias layer are deposited. A chemical mechanical polishing is performed to remove the mask and a reactive ion etching is performed to remove the remaining carbon CMP stop layer. Because the CMP stop layer is very dense and hard, it can be made very thin. This means that when it is removed by reactive ion etching, there is very little notching over the sensor, thereby allowing the upper shield to be very thin.
    Type: Grant
    Filed: December 22, 2009
    Date of Patent: October 30, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Shin Funada, Quang Le, Thomas L. Leong, Jui-Lung Li, Chang-Man Park, Ning Shi, Hicham M. Sougrati
  • Patent number: 8300356
    Abstract: A spin transfer oscillator with a seed/SIL/spacer/FGL/capping configuration is disclosed with a composite seed layer made of Ta and a metal layer having a fcc(111) or hcp(001) texture to enhance perpendicular magnetic anisotropy (PMA) in an overlying (A1/A2)X laminated spin injection layer (SIL). Field generation layer (FGL) is made of a high Bs material such FeCo. Alternatively, the STO has a seed/FGL/spacer/SIL/capping configuration. The SIL may include a FeCo layer that is exchanged coupled with the (A1/A2)X laminate (x is 5 to 50) to improve robustness. The FGL may include an (A1/A2)Y laminate (y=5 to 30) exchange coupled with the high Bs layer to enable easier oscillations. A1 may be one of Co, CoFe, or CoFeR where R is a metal, and A2 is one of Ni, NiCo, or NiFe. The STO may be formed between a main pole and trailing shield in a write head.
    Type: Grant
    Filed: May 11, 2010
    Date of Patent: October 30, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yuchen Zhou
  • Patent number: 8294227
    Abstract: A magnetic cell includes a ferromagnetic free layer having a free magnetization orientation direction and a first ferromagnetic pinned reference layer having a first reference magnetization orientation direction that is parallel or anti-parallel to the free magnetization orientation direction. A first oxide barrier layer is between the ferromagnetic free layer and the first ferromagnetic pinned reference layer. The magnetic cell further includes a second ferromagnetic pinned reference layer having a second reference magnetization orientation direction that is orthogonal to the first reference magnetization orientation direction. The ferromagnetic free layer is between the first ferromagnetic pinned reference layer and the second ferromagnetic pinned reference layer.
    Type: Grant
    Filed: July 5, 2011
    Date of Patent: October 23, 2012
    Assignee: Seagate Technology LLC
    Inventors: Yuankai Zheng, Zheng Gao, Wenzhong Zhu, Wonjoon Jung, Haiwen Xi
  • Patent number: 8294228
    Abstract: A magnetic tunnel junction includes an amorphous ferromagnetic reference layer having a first reference layer side and an opposing second reference layer side. The first reference layer side has a greater concentration of boron than the second reference layer side. A magnesium oxide tunnel barrier layer is disposed on the second side of the amorphous ferromagnetic reference layer. The magnesium oxide tunnel barrier layer has a crystal structure. An amorphous ferromagnetic free layer is disposed on the magnesium oxide tunnel barrier layer.
    Type: Grant
    Filed: May 7, 2012
    Date of Patent: October 23, 2012
    Assignee: Seagate Technology LLC
    Inventors: Xilin Peng, Konstantin Nikolaev, Taras Pokhil, Victor Sapazhnikov, Yonghua Chen
  • Patent number: 8287944
    Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.
    Type: Grant
    Filed: March 28, 2011
    Date of Patent: October 16, 2012
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Haiwen Xi
  • Patent number: 8289662
    Abstract: A device in one embodiment includes a plurality of tunnel junction resistors coupled in series; a first lead coupled to one end of the plurality of tunnel junction resistors coupled in series; and a second lead coupled to another end of the plurality of tunnel junction resistors coupled in series. A device in another embodiment includes a magnetoresistive sensor; a plurality of tunnel junction resistors coupled in series; a first lead coupling one end of the magnetoresistive sensor to one end of the plurality of tunnel junction resistors coupled in series; and a second lead coupling another end of the magnetoresistive sensor to another end of the plurality of tunnel junction resistors coupled in series.
    Type: Grant
    Filed: May 20, 2008
    Date of Patent: October 16, 2012
    Assignee: International Business Machines Corporation
    Inventor: Icko E. T. Iben
  • Patent number: 8288023
    Abstract: A magnetic tunnel junction cell having a free layer, a ferromagnetic pinned layer, and a barrier layer therebetween. The free layer has a central ferromagnetic portion and a stabilizing portion radially proximate the central ferromagnetic portion. The construction can be used for both in-plane magnetic memory cells where the magnetization orientation of the magnetic layer is in the stack film plane and out-of-plane magnetic memory cells where the magnetization orientation of the magnetic layer is out of the stack film plane, e.g., perpendicular to the stack plane.
    Type: Grant
    Filed: December 23, 2010
    Date of Patent: October 16, 2012
    Assignee: Seagate Technology LLC
    Inventors: Kaizhong Gao, Haiwen Xi
  • Patent number: 8289663
    Abstract: A high performance TMR sensor with a spacer including at least one metal layer such as Cu and one or more MgO layers is disclosed. In addition, there may be a metal dopant in the MgO layer. In an alternative embodiment, the MgO layer may be replaced by other low band gap insulating or semiconductor materials. An ultra-low RA of <0.4 ?ohm-cm2 in combination with a MR of 14%, low magnetostriction, and a low Hin value of about 20 Oe is achieved with a composite spacer of the present invention. The Cu layer thickness is from 0.1 to 10 Angstroms and the MgO thickness is from 5 to 20 Angstroms in spacer configurations including Cu/MgO/Cu, and MgO/Cu/MgO.
    Type: Grant
    Filed: April 25, 2008
    Date of Patent: October 16, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Tong Zhao, Hui-Chuan Wang, Min Li
  • Patent number: 8284526
    Abstract: According to one embodiment, a TMR effect element includes a ground layer, an antiferromagnetic layer above the ground layer, a first ferromagnetic layer above the antiferromagnetic layer and exchange-coupled to the antiferromagnetic layer, an anti-parallel coupling layer above the first ferromagnetic layer, a second ferromagnetic layer having a magnetic moment coupled anti-parallel to the magnetic moment of the first ferromagnetic layer via the anti-parallel coupling layer, an insulation barrier layer above the second ferromagnetic layer, and a third ferromagnetic layer above the insulation barrier layer. At least a portion of the second ferromagnetic layer and at least a portion of the third ferromagnetic layer on an insulation barrier layer side are comprised of a crystal, and the insulation barrier layer comprises MgO and an oxide material having an independent cubic crystal structure and complete solid solubility with MgO.
    Type: Grant
    Filed: November 29, 2010
    Date of Patent: October 9, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Koichi Nishioka, Koji Sakamoto, Tatsumi Hirano
  • Patent number: 8283183
    Abstract: A detection device and a detecting method using the detection device are provided in which a magnetic particle is used as a marker particle, and the ratio of a region with reversed magnetization to the whole area of a free layer of a magnetoresistive effect film is increased by a stray magnetic field generated through a biochemical reaction from the magnetic particle remaining on a surface of the magnetoresistive effect film, so that a large detection signal is obtained and obtained detection data can be stored with stability.
    Type: Grant
    Filed: April 26, 2005
    Date of Patent: October 9, 2012
    Assignee: Canon Kabushiki Kaisha
    Inventors: Takashi Ikeda, Norihiko Utsunomiya, Junta Yamamichi
  • Patent number: 8283186
    Abstract: A magnetic memory device and a method for manufacturing the same are disclosed. The magnetic memory device includes a plurality of gates formed on a semiconductor substrate, a source line connected to a source/drain region shared between the gates neighboring with each other, a plurality of magnetic tunnel junctions connected to non-sharing source/drain regions of the gates on a one-to-one basis, and a bit line connected to the magnetic tunnel junctions. The magnetic memory device applies a magnetic memory cell to a memory so as to manufacture a higher-integration magnetic memory, and uses the magnetic memory cell based on a transistor of a DRAM cell, resulting in an increase in the availability of the magnetic memory.
    Type: Grant
    Filed: May 21, 2012
    Date of Patent: October 9, 2012
    Assignees: Hynix Semiconductor Inc., Grandis, Inc.
    Inventor: Hyun Jeong Kim
  • Patent number: 8284527
    Abstract: A magnetic head, according to one embodiment, includes a sensor film, a sensor cap film provided above the sensor film, a pair of shields including an upper magnetic shield and a lower magnetic shield which serve as electrodes that pass current in a film thickness direction of the sensor film, a track insulating film contacting both sides of the sensor film in the track width direction, a graded domain control film arranged on both sides in the track width direction of the sensor film adjacent the track insulating film, and an element height direction insulating film positioned on an opposite side of the sensor film relative to an air-bearing surface, wherein an edge position of the element height direction insulating film adjacent the sensor film on the air-bearing surface side is substantially the same as an edge position of the sensor cap film in the element height direction.
    Type: Grant
    Filed: November 30, 2010
    Date of Patent: October 9, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Nobuo Yoshida, Masato Shiimoto, Kenichi Akita, Kan Yasui
  • Patent number: 8279548
    Abstract: A microwave oscillation element of the present invention includes a lamination main part in which an oscillating layer that is a magnetization free layer and that generates a high frequency electromagnetic field by an excitation of a spin wave, a nonmagnetic intermediate layer, a polarizer layer, and a reference layer that is to be a base magnetic layer of a spin transfer due to application of current are layered in this order. The oscillating layer is made of CoIr, the polarizer layer is configured of CoCr or CoRu; and the nonmagnetic intermediate layer is configured of Cr or Ru. As a result, the efficiency of the spin injection is improved and the microwave oscillation element where the oscillation efficiency is excellent can be realized.
    Type: Grant
    Filed: April 20, 2010
    Date of Patent: October 2, 2012
    Assignee: TDK Corporation
    Inventors: Yoshihiro Tsuchiya, Kiyoshi Noguchi, Migaku Takahashi, Masakiyo Tsunoda
  • Patent number: 8274764
    Abstract: A magneto-resistive effect (MR) element includes a first magnetic layer and a second magnetic layer in which a relative angle of magnetization directions of the first and second magnetic layers changes according to an external magnetic field; and a spacer layer that is provided between the first magnetic layer and the second magnetic layer. The spacer layer contains gallium nitride (GaN) as a main component.
    Type: Grant
    Filed: March 10, 2009
    Date of Patent: September 25, 2012
    Assignee: TDK Corporation
    Inventors: Shinji Hara, Yoshihiro Tsuchiya, Tsutomu Chou, Hironobu Matsuzawa
  • Patent number: 8274811
    Abstract: A spin transfer oscillator (STO) structure is disclosed that includes two assist layers with perpendicular magnetic anisotropy (PMA) to enable a field generation layer (FGL) to achieve an oscillation state at lower current density for MAMR applications. In one embodiment, the STO is formed between a main pole and write shield and the FGL has a synthetic anti-ferromagnetic structure. The STO configuration may be represented by seed layer/spin injection layer (SIL)/spacer/PMA layer 1/FGL/spacer/PMA layer 2/capping layer. The spacer may be Cu for giant magnetoresistive (GMR) devices or a metal oxide for tunneling magnetoresistive (TMR) devices. Alternatively, the FGL is a single ferromagnetic layer and the second PMA assist layer has a synthetic structure including two PMA layers with magnetic moment in opposite directions in a seed layer/SIL/spacer/PMA assist 1/FGL/spacer/PMA assist 2/capping layer configuration. SIL and PMA assist layers are laminates of (CoFe/Ni)x or the like.
    Type: Grant
    Filed: November 22, 2010
    Date of Patent: September 25, 2012
    Assignee: Headway Technologies, Inc.
    Inventors: Kunliang Zhang, Min Li, Yuchen Zhou
  • Patent number: 8270125
    Abstract: A magnetoresistive tunnel junction sensor having improved free layer stability, as well as improved free sensitivity. The free layer is constructed to have a low magnetic coercivity which improves free layer sensitivity. The free layer is also constructed to have a negative magnetostriction which improves free layer stability by preventing the free layer from having an easy axis that is oriented perpendicular to the air bearing surface.
    Type: Grant
    Filed: December 18, 2007
    Date of Patent: September 18, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Hardayal Singh Gill
  • Patent number: 8268641
    Abstract: A method of forming a CPP MTJ MRAM element that utilizes transfer of spin angular momentum as a mechanism for changing the magnetic moment direction of a free layer. The device includes a tunneling barrier layer of MgO and a non-magnetic CPP layer of Cu or Cr and utilizes a novel synthetic free layer having three ferromagnetic layers mutually exchange coupled in pairwise configurations. The free layer comprises an inner ferromagnetic and two outer ferromagnetic layers, with the inner layer being ferromagnetically exchange coupled to one outer layer and anti-ferromagnetically exchange coupled to the other outer layer. The ferromagnetic coupling is very strong across an ultra-thin layer of Ta, Hf or Zr of thickness preferably less than 0.4 nm.
    Type: Grant
    Filed: November 7, 2011
    Date of Patent: September 18, 2012
    Assignee: MagIC Technologies, Inc.
    Inventors: Yimin Guo, Cheng Horng, Ru-Ying Tong
  • Patent number: 8269294
    Abstract: A spin transport device is provided, which includes a channel comprised of a semiconductor material, a magnetization fixed layer arranged on the channel via a first insulating layer, a magnetization free layer arranged on the channel via a second insulating layer, and first and second electrodes arranged on the channel, wherein carrier densities of a first region of the channel including a contact surface with the first insulating layer, a second region of the channel including a contact surface with the second insulating layer, a third region of the channel including an opposite surface to the first electrode, and a fourth region of the channel including an opposite surface to the second electrode are higher than an average carrier density of the whole channel. Accordingly, a spin transport device that can realize good spin transportation and electric resistance characteristics while suppressing the scattering of spin can be provided.
    Type: Grant
    Filed: June 8, 2010
    Date of Patent: September 18, 2012
    Assignee: TDK Corporation
    Inventors: Tomoyuki Sasaki, Tohru Oikawa, Katsumichi Tagami, Masaki Kubota
  • Patent number: 8269295
    Abstract: There is provided a magnetic memory device stable in write characteristics. The magnetic memory device has a recording layer. The planar shape of the recording layer has the maximum length in the direction of the easy-axis over a primary straight line along the easy-axis, and is situated over a length smaller than the half of the maximum length in the direction perpendicular to the easy-axis, and on the one side and on the other side of the primary straight line respectively, the planar shape has a first part situated over a length in the direction perpendicular to the easy-axis, and a second part situated over a length smaller than the length in the direction perpendicular to the easy-axis. The outer edge of the first part includes only a smooth curve convex outwardly of the outer edge.
    Type: Grant
    Filed: April 18, 2011
    Date of Patent: September 18, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Takashi Takenaga, Takeharu Kuroiwa, Hiroshi Takada, Shuichi Ueno, Kiyoshi Kawabata
  • Patent number: 8270127
    Abstract: Magnetoresistive effect elements R1 to R4 are a TMR element or CPP-GMR element. A multilayer film forming the magnetoresistive effect elements is formed to have a width dimension T1 and a length dimension L1 perpendicular to the width dimension T1. The length dimension L1 is longer than the width dimension T1. The width dimension of magnetic field generators of the coil is T2. The multilayer film 31 is positioned within the width dimension T3 of 60% in total of 30% each to the width dimension T2 of the magnetic field generators 3 and 4 of the coil in the direction towards both sides from the center of the width dimension T2 when seen in a plan view.
    Type: Grant
    Filed: March 9, 2011
    Date of Patent: September 18, 2012
    Assignee: Alps Green Devices Co., Ltd.
    Inventors: Yosuke Ide, Masamichi Saito, Akira Takahashi, Masahiro Iizuka, Yoshihiro Nishiyama, Hidekazu Kobayashi
  • Patent number: 8264800
    Abstract: A magnetic field detecting element has a first lower layer, a second lower layer, a tunnel barrier layer, and an upper layer, wherein the first lower layer, the second lower layer, the tunnel barrier layer, and the upper layer are stacked adjacent to each other in this order, the first lower layer is formed in an amorphous state; and the second lower layer is made of cobalt, iron, nickel or a combination thereof and that is formed in a substantially amorphous state, the second lower layer being in touch with the first lower layer and the tunnel barrier layer on both sides and a film thickness of the second lower layer is approximately between 0.2 and 1.5 nm.
    Type: Grant
    Filed: June 29, 2006
    Date of Patent: September 11, 2012
    Assignee: TDK Corporation
    Inventors: Takumi Uesugi, Satoshi Miura
  • Patent number: 8264053
    Abstract: To provide a semiconductor device that has an improved adhesion between a bottom conductive layer and a protection film protecting an MTJ element. This semiconductor device includes a bottom electrode formed over a semiconductor substrate, an MTJ element part formed over a part of the bottom electrode by lamination of a bottom magnetic film, an insulating film, a top magnetic film, and a top electrode in this order, and a protection film formed over the bottom electrode so as to cover the MTJ element part, wherein the bottom electrode is formed by amorphized metal nitride and the protection film is formed by an insulating film containing nitrogen.
    Type: Grant
    Filed: May 29, 2009
    Date of Patent: September 11, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Keisuke Tsukamoto, Mikio Tsujiuchi
  • Patent number: 8256095
    Abstract: An example method for manufacturing a magneto-resistance effect element includes forming a free magnetization layer and forming a spacer layer. The spacer layer is formed, for example, by forming a non-magnetic first metallic layer and forming a second metallic layer on a surface of the non-magnetic first metallic layer. A first irradiating process includes irradiating, onto the second metallic layer, first ions or plasma including at least one of oxygen and nitrogen and at least one selected from the group consisting of Ar, Xe, He, Ne, Kr, so as to convert the second metallic layer into an insulating layer and to form a non-magnetic metallic path penetrating through the insulating layer and containing elements of the non-magnetic first metallic layer. A second irradiating process includes irradiating second ions or plasma onto the insulating layer. A non-magnetic third metallic layer is formed on the non-magnetic metallic path.
    Type: Grant
    Filed: August 30, 2010
    Date of Patent: September 4, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiromi Yuasa, Hideaki Fukuzawa, Yoshihiko Fuji
  • Patent number: 8258592
    Abstract: A semiconductor device having a MTJ device excellent in operating characteristics and a manufacturing method therefor are provided. The MTJ device is formed of a laminated structure which is obtained by laminating a lower magnetic film, a tunnel insulating film, and an upper magnetic film in this order. The lower and upper magnetic films contain noncrystalline or microcrystalline ferrocobalt boron (CoFeB) as a constituent material. The tunnel insulating film contains aluminum oxide (AlOx) as a constituent material. A CAP layer is formed over the upper magnetic film and a hard mask is formed over the CAP layer. The CAP layer contains a substance of crystalline ruthenium (Ru) as a constituent material and the hard mask contains a substance of crystalline tantalum (Ta) as a constituent material. The film thickness of the hard mask is larger than that of the CAP layer.
    Type: Grant
    Filed: May 11, 2009
    Date of Patent: September 4, 2012
    Assignee: Renesas Electronics Corporation
    Inventors: Ryoji Matsuda, Shuichi Ueno, Haruo Furuta, Takashi Takenaga, Takeharu Kuroiwa
  • Patent number: 8254067
    Abstract: As recording density of sensors is increased, it is desired to lower the areal resistivity (RA) of TMR sensors. Decreasing RA to 1.0 ??m2 or below badly influences the read signal since the interlayer coupling magnetic field (Hint) between the pinned layer and the free layer increases sharply and impedes the free rotation of magnetization of the free layer. According to one embodiment, a tunnel junction type magneto-resistive head solves this problem by having a layered film comprising an underlying layer, a crystalline orientation control layer, an antiferromagnetic layer, a first ferromagnetic layer, an antiparallel coupling layer, a second ferromagnetic layer, an insulation barrier layer, and a third ferromagnetic layer between a lower magnetic shield layer and an upper magnetic shield layer, wherein a crystallographic plane of the antiferromagnetic layer is directed parallel to a film surface by growing the antiferromagnetic layer substantially conformably on the crystalline orientation control layer.
    Type: Grant
    Filed: September 21, 2009
    Date of Patent: August 28, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Koichi Nishioka, Hiroaki Chihaya
  • Patent number: 8253210
    Abstract: A semiconductor device includes a magnetic sensor chip, an electrically conducting layer wafer-level patterned in contact with the magnetic sensor chip, encapsulation material disposed on the magnetic sensor chip, and an array of external contact elements electrically coupled with the magnetic sensor chip through the electrically conducting layer.
    Type: Grant
    Filed: April 30, 2009
    Date of Patent: August 28, 2012
    Assignee: Infineon Technologies AG
    Inventors: Horst Theuss, Klaus Elian
  • Patent number: 8240026
    Abstract: A method for manufacturing a magneto-resistive device. The magneto-resistive device is for reducing the deterioration in the characteristics of the device due to annealing. The magneto-resistive device has a magneto-resistive layer formed on one surface side of a base, and an insulating layer formed of two layers and deposited around the magneto-resistive layer. The layer of the insulating layer closest to the base is made of a metal or semiconductor oxide. This layer extends over end faces of a plurality of layers made of different materials from one another, which make up the magneto-resistive device, and is in contact with the end faces of the plurality of layers with the same materials.
    Type: Grant
    Filed: September 24, 2008
    Date of Patent: August 14, 2012
    Assignee: TDK Corporation
    Inventors: Takeo Kagami, Tetsuya Kuwashima, Norio Takahashi
  • Patent number: 8243401
    Abstract: A tunneling magnetoresistance (TMR) read sensor with a Co—Fe—B lower sense layer and a Co—Hf upper sense layer is disclosed. In order for the dual sense layers to exhibit a negative saturation magnetostriction (?S), their Fe contents are either substantially reduced or even eliminated, instead of adding a conventional Ni—Fe film as an additional sense layer. By optimizing compositions and thicknesses of the dual sense layers, the dual sense layers indeed exhibit a negative ?S, while the TMR sensor exhibits a TMR coefficient (?RT/RJ) of greater than 80% at a junction resistance-area product (RJAJ) of less than 2 ?-?m2.
    Type: Grant
    Filed: October 2, 2009
    Date of Patent: August 14, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Tsann Lin
  • Patent number: 8243400
    Abstract: A magnetoresistive effect element includes a first ferromagnetic layer, Cr layer, Heusler alloy layer, barrier layer, and second ferromagnetic layer. The first ferromagnetic layer has the body-centered cubic lattice structure. The Cr layer is formed on the first ferromagnetic layer and has the body-centered cubic lattice structure. The Heusler alloy layer is formed on the Cr layer. The barrier layer is formed on the Heusler alloy layer. The second ferromagnetic layer is formed on the barrier layer.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: August 14, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Mizue Ishikawa, Yoshiaki Saito, Hideyuki Sugiyama, Tomoaki Inokuchi
  • Patent number: 8243398
    Abstract: A magneto-resistive (MR) device for reading at least one of a legacy data and a present data magnetically recorded on at least one legacy track and a least one present track, respectively, is provided. The device comprises first and second MR elements, and first, second, and third permanent magnets. The first MR read element is positioned between the first and the second permanent magnets to stabilize the first MR read element while reading the legacy data from the media. The second MR element is positioned adjacent to the second permanent magnet and configured to read the present data from the media. The third permanent magnet is positioned adjacent to the second MR element and opposite to the second permanent magnet. The second and the third permanent magnets cooperate with each other to stabilize the second MR read element while reading the present data from the media.
    Type: Grant
    Filed: June 18, 2008
    Date of Patent: August 14, 2012
    Assignee: Oracle America, Inc.
    Inventors: Charles C. Partee, John P. Nibarger
  • Patent number: 8242776
    Abstract: A semiconductor process and apparatus provide a high-performance magnetic field sensor from two differential sensor configurations (201, 211) which require only two distinct pinning axes (206, 216), where each differential sensor (e.g., 201) is formed from a Wheatstone bridge structure with four unshielded MTJ sensors (202-205), each of which includes a magnetic field pulse generator (e.g., 414) for selectively applying a field pulse to stabilize or restore the easy axis magnetization of the sense layers (e.g., 411) to eliminate micromagnetic domain switches during measurements of small magnetic fields.
    Type: Grant
    Filed: March 26, 2008
    Date of Patent: August 14, 2012
    Assignee: Everspin Technologies, Inc.
    Inventors: Phillip G. Mather, Young Sir Chung, Bradley N. Engel
  • Patent number: 8236576
    Abstract: A magnetic logic element with toroidal magnetic multilayers (5,6,8,9). The magnetic logic element comprises a toroidal closed section which is fabricated by etching a unit of magnetic multilayers (5,6,8,9) deposited on a substrate. Optionally, the magnetic logic element may also comprise a metal core (10) in the closed toroidal section. Said magnetic multilayers (5,6,8,9) unit is arranged on the input signal lines A, B, C and an output signal line O, and then is made into a closed toroidal. Subsequently, on the toroidal magnetic multilayered unit (5,6,8,9), the input signal lines A?, B?, C? and an output signal line O? are fabricated by etching. This magnetic logic element can reduce the demagnetization field and the shape anisotropy effectively, leading to the decrease of the reversal field of magnetic free layer. Furthermore, this magnetic logic element has stable working performance and long operation life of the device.
    Type: Grant
    Filed: April 11, 2007
    Date of Patent: August 7, 2012
    Assignee: Institute of Physics, Chinese Academy of Sciences
    Inventors: Xiufeng Han, Zhongming Zeng, Yunan Han, Lixian Jiang, Zilong Peng, Wenshan Zhan
  • Patent number: 8238064
    Abstract: Embodiments of the present invention provide an accumulation element with high resolving power and high output suitable for magnetic recording and reproducing at high recording density. According to one embodiment, a plurality of spin injection parts and are provided to increase the total amount of spin electrons. The spin accumulation element is composed of a non-magnetic conductor, a first magnetic conductor, a second magnetic conductor, and a third magnetic conductor, each of which are in contact with the non-magnetic conductor through the tunneling junction. An output voltage due to the spin accumulation effect is detected as a potential difference between the non-magnetic conductor and the third magnetic conductor.
    Type: Grant
    Filed: December 3, 2008
    Date of Patent: August 7, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Masaki Yamada, Hiromasa Takahashi
  • Patent number: 8233249
    Abstract: A magnetic tunnel junction transistor (MTJT) device includes a source-drain region comprising a source electrode and a drain electrode, a double MTJ element formed between the source electrode and the drain electrode and comprising a free magnetic layer at a center region thereof, and a gate region adjacent to the source-drain region and comprising an insulating barrier layer formed on an upper layer of the double MTJ element and a gate electrode formed on the insulating barrier layer. The MTJT device switches a magnetization orientation of the free magnetic layer by application of a gate voltage to the gate electrode, thereby changing a resistance of the source-drain region.
    Type: Grant
    Filed: January 4, 2010
    Date of Patent: July 31, 2012
    Assignee: International Business Machines Corporation
    Inventor: Daniel C. Worledge
  • Patent number: 8225489
    Abstract: An MR element includes a first exchange coupling shield layer, an MR stack, and a second exchange coupling shield layer that are arranged in this order from the bottom, and a nonmagnetic layer surrounding the MR stack. The MR stack includes a first free layer, a spacer layer, a second free layer, and a magnetic cap layer that are arranged in this order from the bottom. In the step of forming the MR stack and the nonmagnetic layer, a protection layer is formed on a layered film that will be the MR stack later, and a mask is then formed on the protection layer. Next, the layered film and the protection layer are etched using the mask and then the nonmagnetic layer is formed. After removal of the mask, the protection layer is removed by wet etching.
    Type: Grant
    Filed: March 26, 2010
    Date of Patent: July 24, 2012
    Assignee: TDK Corporation
    Inventors: Daisuke Miyauchi, Takahiko Machita, Keita Kawamori
  • Patent number: 8225487
    Abstract: A method according to one embodiment includes forming a mask above a thin film sensor stack; forming an electrically insulating layer above the mask and sensor stack, the insulating layer having a portion extending along a nonhorizontal end of the mask; selectively removing the insulating layer except for the portion thereof extending along the nonhorizontal end of the mask; removing portions of the sensor stack that are not covered by the mask and the portion of the insulating layer, wherein an end of the portion of the insulating layer positioned away from the mask is about aligned with a back end of the sensor stack after removing the portions thereof; and removing the mask.
    Type: Grant
    Filed: July 25, 2008
    Date of Patent: July 24, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventors: Ying Hong, Edward Hin Pong Lee, Aron Pentek, David John Seagle
  • Patent number: 8218271
    Abstract: According to one embodiment, a method for forming at least a portion of a magnetic head includes forming a keeper layer, forming a reference layer, and forming an AFM coupling layer which is positioned between the keeper layer and the reference layer. In addition, forming the reference layer includes forming a layer of CoFe, depositing a layer of CoFeHf which is about 20 atomic % Hf, and depositing a layer of CoFeB such that the layers of CoFeHf and CoFeB are directly adjacent and a ratio of respective physical thicknesses of CoFeHf to CoFeB is less than about 0.66. Other embodiments are also included such as a magnetic head and additional methods for forming at least a portion of a magnetic head.
    Type: Grant
    Filed: July 22, 2009
    Date of Patent: July 10, 2012
    Assignee: Hitachi Global Storage Technologies Netherlands B.V.
    Inventor: Alexander M. Zeltser
  • Patent number: 8216703
    Abstract: A magnetic tunnel junction (MTJ) (10) employing a dielectric tunneling barrier (16), useful in magnetoresistive random access memories (MRAMs) and other devices, has a synthetic antiferromagnet (SAF) structure (14, 16), comprising two ferromagnetic (FM) layers (26, 41; 51, 58; 61, 68) separated by a coupling layer (38, 56, 66). Improved magnetoresistance (MR) ratio is obtained by providing a further layer (44, 46, 46?, 47, 52, 62), e.g. containing Ta, preferably spaced apart from the coupling layer (38, 56, 66) by a FM layer (41, 30-2, 54). The further layer (44, 46, 46?, 47, 52, 62) may be a Ta dusting layer (44) covered by a FM layer (30-2), or a Ta containing FM alloyed layer (46), or a stack (46?) of interleaved FM and N-FM layers, or other combination (47, 62). Furthering these benefits, another FM layer, e.g., CoFe, NiFe, (30, 30-1, 51, 61) is desirably provided between the further layer (44, 46, 46?, 47, 52, 62) and the tunneling barrier (16).
    Type: Grant
    Filed: February 21, 2008
    Date of Patent: July 10, 2012
    Assignee: Everspin Technologies, Inc.
    Inventors: Jijun Sun, Jon M. Slaughter