Patents by Inventor Susumu Okamura

Susumu Okamura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20240112840
    Abstract: Embodiments of the present disclosure relate to a cobalt-boron (CoB) layer for magnetic recording devices, memory devices, and storage devices. In one or more embodiments, the CoB layer is part of a spin-orbit torque (SOT) device. In one or more embodiments, the SOT device is part of an SOT based sensor, an SOT based writer, a memory device (such as a magnetoresistive random-access memory (MRAM) device), and/or a storage device (such as a hard disk drive (HDD) or a tape drive). In one embodiment, an SOT device includes a seed layer, and a cap layer spaced from the seed layer. The SOT device includes a spin-orbit torque (SOT) layer, and a nano layer (NL) between the seed layer and the cap layer. The SOT device includes a cobalt-boron (CoB) layer between the seed layer and the cap layer, and the CoB layer is ferromagnetic.
    Type: Application
    Filed: September 29, 2022
    Publication date: April 4, 2024
    Applicant: Western Digital Technologies, Inc.
    Inventors: Susumu OKAMURA, Quang LE, Brian R. YORK, Cherngye HWANG, Randy G. SIMMONS, Kuok San HO, Hisashi TAKANO
  • Publication number: 20240107893
    Abstract: The present disclosure generally relates to magnetoresistive (MR) devices. The MR device comprises a synthetic antiferromagnetic (SAF) layer that increases exchange coupling field, and in turn, less magnetic noise of such devices. The MR device comprises a first ferromagnetic (FM1) layer and a second ferromagnetic (FM2) layer, in between which is an SAF spacer of RuAl alloy having a B2 crystalline structure which may grow epitaxial on BCC (110) or FCC (111) textures, meaning that the (110) or (111) plane is parallel to the surface of MR device substrate. Further, amorphous layers may be inserted into the device structure to reset the growth texture of the device to a (001), (110), or (111) texture in order to promote the growth of tunneling barrier layers or antiferromagnetic (AF) pinning layers.
    Type: Application
    Filed: September 23, 2022
    Publication date: March 28, 2024
    Applicant: Western Digital Technologies, Inc.
    Inventors: Susumu OKAMURA, James Mac FREITAG, Yuankai ZHENG, Brian R. YORK
  • Publication number: 20240087785
    Abstract: The present disclosure generally relates to magnetoresistive (MR) devices. The MR device comprises a synthetic antiferromagnetic (SAF) layer that increases stability to magnetic fields, and in turn, results in lower magnetic noise of the device. The MR device comprises a first ferromagnetic (FM1) layer and a second ferromagnetic (FM2) layer, in between which is an SAF spacer of RuAl alloy having a B2 crystalline structure with (001) texture, meaning that the (001) plane is parallel to the surface of MR device substrate. The first ferromagnetic (FM1) layer and a part of the second ferromagnetic (FM2) layer also have the (001) texture. An amorphous layer in a second ferromagnetic (FM2) layer can reset the growth texture of the MR device to a (111) texture in order to promote the growth of an antiferromagnetic (AF) pinning layer.
    Type: Application
    Filed: September 14, 2022
    Publication date: March 14, 2024
    Applicant: Western Digital Technologies, Inc.
    Inventors: Susumu OKAMURA, James Mac FREITAG, Yuankai ZHENG, Brian R. YORK
  • Patent number: 11925120
    Abstract: Embodiments of the present disclosure generally relate to spintronic devices, and more specifically to self-cooling spintronic devices. In an embodiment, a device is provided. The device includes a spintronic device having a first side and a second side opposite the first side, a first layer disposed on the first side, and a second layer disposed on the second side, the first layer having a Seebeck coefficient that is different from a Seebeck coefficient of the second layer.
    Type: Grant
    Filed: July 28, 2021
    Date of Patent: March 5, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: Susumu Okamura, Christian Kaiser, Xinjiang Shen, Yongchul Ahn, James Mac Freitag
  • Patent number: 11908496
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) devices comprising a topological insulator (TI) modulation layer. The TI modulation layer comprises a plurality of bismuth or bismuth-rich composition modulation layers, a plurality of TI lamellae layers comprising BiSb having a (012) crystal orientation, and a plurality of texturing layers. The TI lamellae layers comprise dopants or clusters of atoms, the clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material. The clusters of atoms are configured to have a grain boundary glass forming temperature of less than about 400° C. Doping the TI lamellae layers comprising BiSb having a (012) crystal orientation with clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material enable the SOT MTJ device to operate at higher temperatures while inhibiting migration of Sb from the BiSb of the TI lamellae layers.
    Type: Grant
    Filed: December 16, 2022
    Date of Patent: February 20, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Brian R. York, Cherngye Hwang, Susumu Okamura, Xiaoyong Liu, Kuok San Ho, Hisashi Takano
  • Publication number: 20240032437
    Abstract: The present disclosure generally relates to spin-orbit torque (SOT) devices comprising a bismuth antimony (BiSb) layer. The SOT devices further comprises a nonmagnetic buffer layer, a nonmagnetic interlayer, a ferromagnetic layer, and a nonmagnetic barrier layer. One or more of the barrier layer, interlayer, and buffer layer comprise a polycrystalline non-Heusler alloy material, or a Heusler alloy and a material selected from the group consisting of: Cu, Ag, Ge, Mn, Ni, Co, Mo, W, Sn, B, and In. The Heusler alloy is a full Heusler alloy comprising X2YZ or a half Heusler alloy comprising XYZ, where X is one of: Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt, and Au, Y is one of: Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Y, Zr, Nb, Mo, Hf, and W, and Z is one of: B, Al, Si, Ga, Ge, As, In, Sn, Sb, and Bi.
    Type: Application
    Filed: May 15, 2023
    Publication date: January 25, 2024
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Brian R. YORK, Cherngye HWANG, Xiaoyong LIU, Susumu OKAMURA, Michael A. GRIBELYUK, Xiaoyu XU, Randy G. SIMMONS, Kuok San HO, Hisashi TAKANO
  • Patent number: 11881236
    Abstract: The present disclosure generally relates to a magnetic recording head comprising a spintronic device. The spintronic device is disposed between a main pole and a trailing shield of the magnetic recording head. The spintronic device comprises a multilayer spacer layer comprising a Cu layer in contact with a spin torque layer and a spin transparent texture layer disposed on the Cu layer, the spin transparent texture layer comprising AgSn or AgZn. A multilayer notch comprising a CoFe layer is disposed over the spin transparent texture layer of the multilayer spacer layer and a Heusler alloy layer is disposed on the CoFe layer, the Heusler alloy layer comprising CoMnGe, CoFeGe, or CoFeMnGe. The multilayer spacer layer and the multilayer notch result in the spintronic device having a high spin polarization and a reduced critical current.
    Type: Grant
    Filed: June 21, 2022
    Date of Patent: January 23, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Mac Freitag, Susumu Okamura, Christian Kaiser
  • Publication number: 20240005973
    Abstract: The present disclosure generally relates to spin-orbit torque (SOT) devices comprising a bismuth antimony (BiSb) layer. The SOT devices further comprise one or more GexNiFe layers, where at least one GexNiFe layer is disposed in contact with the BiSb layer. The GexNiFe layer has a thickness less than or equal to about 15 ? when used as an interlayer on top of the BiSb layer or less than or equal to 40 ? when used as a buffer layer underneath the BiSb. When the BiSb layer is doped with a dopant comprising a gas, a metal, a non-metal, or a ceramic material, the GexNiFe layer promotes the BiSb layer to have a (012) orientation. When the BiSb layer is undoped, the GexNiFe layer promotes the BiSb layer to have a (001) orientation. Utilizing the GexNiFe layer allows the crystal orientation of the BiSb layer to be selected.
    Type: Application
    Filed: June 30, 2022
    Publication date: January 4, 2024
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Brian R. YORK, Cherngye HWANG, Xiaoyong LIU, Michael A. GRIBELYUK, Xiaoyu XU, Susumu OKAMURA, Kuok San HO, Hisashi TAKANO, Randy G. SIMMONS
  • Publication number: 20240005951
    Abstract: Aspects of the present disclosure generally relate to magnetic recording heads (such as write heads of data storage devices) that include multilayer structures to facilitate targeted switching and relatively low coercivity. In one or more embodiments, a magnetic recording head includes an iron-cobalt (FeCo) layer having a crystalline structure that is a cubic lattice structure, a first crystalline layer formed of a first material, and a second crystalline layer between the first crystalline layer and the FeCo layer. The second crystalline layer is formed of a second material different from the first material, and the second crystalline layer interfaces both the FeCo layer and the first crystalline layer. The crystalline structure of the FeCo layer has a texture of <100>.
    Type: Application
    Filed: June 30, 2022
    Publication date: January 4, 2024
    Applicant: Western Digital Technologies, Inc.
    Inventors: Ning SHI, Brian R. YORK, Susumu OKAMURA, Suping SONG
  • Patent number: 11862205
    Abstract: The present disclosure generally relates to a magnetic recording device having a magnetic recording head comprising a spintronic device. The spintronic device is disposed between a main pole and a trailing shield at a media facing surface. The spintronic device comprises a spin torque layer (STL) and a multilayer seed layer disposed in contact with the STL. The spintronic device may further comprise a field generation layer disposed between the trailing shield and the STL. The multilayer seed layer comprises an optional high etch rate layer, a heat dissipation layer comprising Ru disposed in contact with the optional high etch rate layer, and a cooling layer comprising Cr disposed in contact with the heat dissipation layer and the main pole. The high etch rate layer comprises Cu and has a high etch rate to improve the shape of the spintronic device during the manufacturing process.
    Type: Grant
    Filed: June 21, 2022
    Date of Patent: January 2, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Mac Freitag, Yongchul Ahn, Susumu Okamura, Christian Kaiser
  • Publication number: 20230410841
    Abstract: The present disclosure generally relates to a magnetic recording head comprising a spintronic device. The spintronic device is disposed between a main pole and a trailing shield of the magnetic recording head. The spintronic device comprises a multilayer spacer layer comprising a Cu layer in contact with a spin torque layer and a spin transparent texture layer disposed on the Cu layer, the spin transparent texture layer comprising AgSn or AgZn. A multilayer notch comprising a CoFe layer is disposed over the spin transparent texture layer of the multilayer spacer layer and a Heusler alloy layer is disposed on the CoFe layer, the Heusler alloy layer comprising CoMnGe, CoFeGe, or CoFeMnGe. The multilayer spacer layer and the multilayer notch result in the spintronic device having a high spin polarization and a reduced critical current.
    Type: Application
    Filed: June 21, 2022
    Publication date: December 21, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: James Mac FREITAG, Susumu OKAMURA, Christian KAISER
  • Publication number: 20230410840
    Abstract: The present disclosure generally relates to a magnetic recording device having a magnetic recording head comprising a spintronic device. The spintronic device is disposed between a main pole and a trailing shield at a media facing surface. The spintronic device comprises a spin torque layer (STL) and a multilayer seed layer disposed in contact with the STL. The spintronic device may further comprise a field generation layer disposed between the trailing shield and the STL. The multilayer seed layer comprises an optional high etch rate layer, a heat dissipation layer comprising Ru disposed in contact with the optional high etch rate layer, and a cooling layer comprising Cr disposed in contact with the heat dissipation layer and the main pole. The high etch rate layer comprises Cu and has a high etch rate to improve the shape of the spintronic device during the manufacturing process.
    Type: Application
    Filed: June 21, 2022
    Publication date: December 21, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: James Mac FREITAG, Yongchul AHN, Susumu OKAMURA, Christian KAISER
  • Publication number: 20230386721
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a buffer layer, a bismuth antimony (BiSb) layer having a (012) orientation disposed on the buffer layer, and an interlayer disposed on the BiSb layer. The buffer layer and the interlayer may each independently be a single layer of material or a multilayer of material. The buffer layer and the interlayer each comprise at least one of a covalently bonded amorphous material, a tetragonal (001) material, a tetragonal (110) material, a body-centered cubic (bcc) (100) material, a face-centered cubic (fcc) (100) material, a textured bcc (100) material, a textured fcc (100) material, a textured (100) material, or an amorphous metallic material. The buffer layer and the interlayer inhibit antimony (Sb) migration within the BiSb layer and enhance uniformity of the BiSb layer while further promoting the (012) orientation of the BiSb layer.
    Type: Application
    Filed: August 9, 2023
    Publication date: November 30, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Brian R. YORK, Cherngye HWANG, Susumu OKAMURA, Michael A. GRIBELYUK, Xiaoyong LIU, Kuok San HO, Hisashi TAKANO
  • Patent number: 11763973
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a buffer layer, a bismuth antimony (BiSb) layer having a (012) orientation disposed on the buffer layer, and an interlayer disposed on the BiSb layer. The buffer layer and the interlayer may each independently be a single layer of material or a multilayer of material. The buffer layer and the interlayer each comprise at least one of a covalently bonded amorphous material, a tetragonal (001) material, a tetragonal (110) material, a body-centered cubic (bcc) (100) material, a face-centered cubic (fcc) (100) material, a textured bcc (100) material, a textured fcc (100) material, a textured (100) material, or an amorphous metallic material. The buffer layer and the interlayer inhibit antimony (Sb) migration within the BiSb layer and enhance uniformity of the BiSb layer while further promoting the (012) orientation of the BiSb layer.
    Type: Grant
    Filed: August 13, 2021
    Date of Patent: September 19, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Brian R. York, Cherngye Hwang, Susumu Okamura, Michael Gribelyuk, Xiaoyong Liu, Kuok San Ho, Hisashi Takano
  • Patent number: 11683993
    Abstract: Aspects of the present disclosure generally relate to a spintronic device for use in a magnetic media drive, a magnetoresistive random access memory device, a magnetic sensor, or a magnetic recording write head. The spintronic device comprises a multilayer structure having a negative anisotropic field and a negative spin polarization. The multilayer structure comprises a plurality of layers, each layer of the plurality of layers comprising a first sublayer comprising Fe and a second sublayer comprising Co. At least one of the first sublayer and the second sublayer comprises one or more of Cr, V, and Ti. The first and second sublayers are alternating. The negative anisotropic field of the multilayer structure is between about ?0.5 T to about ?0.8 T, and an effective magnetization of the multilayer structure is between about 2.4 T to about 2.8 T.
    Type: Grant
    Filed: March 23, 2021
    Date of Patent: June 20, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: Susumu Okamura, Christian Kaiser, James Mac Freitag
  • Patent number: 11682420
    Abstract: Certain embodiments are directed to a spin torque oscillator (STO) device in a microwave assisted magnetic recording (MAMR) device. The magnetic recording head includes a seed layer, a spin polarization layer over the seed layer, a spacer layer over the spin polarization layer, and a field generation layer is over the spacer layer. In one embodiment, the seed layer comprises a tantalum alloy layer. In another embodiment, the seed layer comprises a template layer and a damping reduction layer over the template layer. In yet another embodiment, the seed layer comprises a texture reset layer, a template layer on the texture reset layer, and a damping reduction layer on the template layer.
    Type: Grant
    Filed: August 31, 2021
    Date of Patent: June 20, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Mac Freitag, Zheng Gao, Susumu Okamura, Brian R. York
  • Patent number: 11657836
    Abstract: Aspects of the present disclosure generally relate to a magnetic recording head of a spintronic device, such as a write head of a data storage device, for example a magnetic media drive. In one example, a magnetic recording head includes a main pole, a trailing shield, and a spin torque layer (STL) between the main pole and the trailing shield. The magnetic recording head includes a first layer structure on the main pole, and the first layer structure includes a negative polarization layer. The magnetic recording head also includes a second layer structure disposed on the negative polarization layer and between the negative polarization layer and the STL. The negative polarization layer is an FeCr layer. The second layer structure includes a Cr layer disposed on the FeCr layer, and a Cu layer disposed on the Cr layer and between the Cr layer and the STL.
    Type: Grant
    Filed: January 28, 2022
    Date of Patent: May 23, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Mac Freitag, Susumu Okamura, Alexander Goncharov, Zheng Gao
  • Publication number: 20230121375
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) devices comprising a topological insulator (TI) modulation layer. The TI modulation layer comprises a plurality of bismuth or bismuth-rich composition modulation layers, a plurality of TI lamellae layers comprising BiSb having a (012) crystal orientation, and a plurality of texturing layers. The TI lamellae layers comprise dopants or clusters of atoms, the clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material. The clusters of atoms are configured to have a grain boundary glass forming temperature of less than about 400° C. Doping the TI lamellae layers comprising BiSb having a (012) crystal orientation with clusters of atoms comprising a carbide, a nitride, an oxide, or a composite ceramic material enable the SOT MTJ device to operate at higher temperatures while inhibiting migration of Sb from the BiSb of the TI lamellae layers.
    Type: Application
    Filed: December 16, 2022
    Publication date: April 20, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Brian R. YORK, Cherngye HWANG, Susumu OKAMURA, Xiaoyong LIU, Kuok San HO, Hisashi TAKANO
  • Publication number: 20230084970
    Abstract: A tunneling magnetoresistance (TMR) device has an improved seed layer for the lower or first ferromagnetic layer that eliminates the need for boron in the two ferromagnetic layers. The seed layer, for example a RuAl alloy, has a B2 crystalline structure with (001) texture when deposited on an amorphous pre-seed layer, meaning that the (001) plane is parallel to the surface of the TMR device substrate. The subsequently deposited first ferromagnetic layer, like a CoFe alloy, and the tunneling barrier layer, typically MgO, inherit the (001) texture of the seed layer.
    Type: Application
    Filed: September 10, 2021
    Publication date: March 16, 2023
    Inventors: Susumu Okamura, Christian Kaiser, Brian R. York
  • Publication number: 20230047223
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a buffer layer, a bismuth antimony (BiSb) layer having a (012) orientation disposed on the buffer layer, and an interlayer disposed on the BiSb layer. The buffer layer and the interlayer may each independently be a single layer of material or a multilayer of material. The buffer layer and the interlayer each comprise at least one of a covalently bonded amorphous material, a tetragonal (001) material, a tetragonal (110) material, a body-centered cubic (bcc) (100) material, a face-centered cubic (fcc) (100) material, a textured bcc (100) material, a textured fcc (100) material, a textured (100) material, or an amorphous metallic material. The buffer layer and the interlayer inhibit antimony (Sb) migration within the BiSb layer and enhance uniformity of the BiSb layer while further promoting the (012) orientation of the BiSb layer.
    Type: Application
    Filed: August 13, 2021
    Publication date: February 16, 2023
    Inventors: Quang LE, Brian R. YORK, Cherngye HWANG, Susumu OKAMURA, Michael GRIBELYUK, Xiaoyong LIU, Kuok San HO, Hisashi TAKANO