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: 20210376793
    Abstract: A spin torque oscillator includes a first electrode, a second electrode and a device layer stack located between the first electrode and the second electrode. The device layer stack includes a spin polarization layer including a first ferromagnetic material, an assist layer including a third ferromagnetic material, a ferromagnetic oscillation layer including a second ferromagnetic material located between the spin polarization layer and the assist layer, a nonmagnetic spacer layer located between the spin polarization layer and the ferromagnetic oscillation, and a nonmagnetic coupling layer located between the ferromagnetic oscillation layer and the assist layer. The assist layer is antiferromagnetically coupled to the ferromagnetic oscillation layer through the non-magnetic coupling layer, and the assist layer has a magnetization that is coupled to a magnetization of the ferromagnetic oscillation layer.
    Type: Application
    Filed: May 29, 2020
    Publication date: December 2, 2021
    Inventors: Yuankai Zheng, Zheng Gao, Susumu Okamura, James Freitag
  • Publication number: 20210375518
    Abstract: A spin torque oscillator includes a first electrode, a second electrode and a device layer stack located between the first electrode and the second electrode. The device layer stack includes a spin polarization layer including a first ferromagnetic material, an assist layer including a third ferromagnetic material, a ferromagnetic oscillation layer including a second ferromagnetic material located between the spin polarization layer and the assist layer, a nonmagnetic spacer layer located between the spin polarization layer and the ferromagnetic oscillation, and a nonmagnetic coupling layer located between the ferromagnetic oscillation layer and the assist layer. The assist layer is antiferromagnetically coupled to the ferromagnetic oscillation layer through the non-magnetic coupling layer, and the assist layer has a magnetization that is coupled to a magnetization of the ferromagnetic oscillation layer.
    Type: Application
    Filed: May 29, 2020
    Publication date: December 2, 2021
    Inventors: Yuankai Zheng, Zheng Gao, Susumu Okamura, James Freitag
  • Patent number: 11171605
    Abstract: A spin torque oscillator includes a first electrode, a second electrode and a device layer stack located between the first electrode and the second electrode. The device layer stack includes a spin polarization layer including a first ferromagnetic material, an assist layer including a third ferromagnetic material, a ferromagnetic oscillation layer including a second ferromagnetic material located between the spin polarization layer and the assist layer, a nonmagnetic spacer layer located between the spin polarization layer and the ferromagnetic oscillation, and a nonmagnetic coupling layer located between the ferromagnetic oscillation layer and the assist layer. The assist layer is antiferromagnetically coupled to the ferromagnetic oscillation layer through the non-magnetic coupling layer, and the assist layer has a magnetization that is coupled to a magnetization of the ferromagnetic oscillation layer.
    Type: Grant
    Filed: May 29, 2020
    Date of Patent: November 9, 2021
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Yuankai Zheng, Zheng Gao, Susumu Okamura, James Freitag
  • Patent number: 11127420
    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: June 24, 2019
    Date of Patent: September 21, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Mac Freitag, Zheng Gao, Susumu Okamura, Brian York
  • Patent number: 10997992
    Abstract: A spin transfer torque (STT) device is formed on an electrically conductive substrate and includes a ferromagnetic free layer near the substrate, a ferromagnetic polarizing layer and a nonmagnetic spacer layer between the free layer and the polarizing layer. A multilayer structure is located between the substrate and the free layer. The multilayer structure includes a metal or metal alloy seed layer for the free layer and an intermediate oxide layer below and in contact with the seed layer. The intermediate oxide layer reflects spin current from the free layer and thus reduces undesirable damping of the oscillation of the free layer's magnetization by the seed layer.
    Type: Grant
    Filed: September 16, 2019
    Date of Patent: May 4, 2021
    Assignee: Western Digital Technologies, Inc.
    Inventors: James Mac Freitag, Susumu Okamura, Masahiko Hashimoto, Zheng Gao
  • Patent number: 10950258
    Abstract: Aspects of the present disclosure relate to spin torque oscillator (STO) and methods, such as spin torque oscillators used in write heads of magnetic media drives. The STO includes a seed layer, a spin polarization layer (SPL), a spacer layer, a field generation layer (FGL), a capping layer. An insertion layer is disposed within the STO. The insertion layer increases the negative Hk. The insertion layer may be located between the FGL and the capping layer, as well as between the FGL and the spacer layer. For a reverse STO, the insertion layer may be disposed between the FGL and the seed layer, as well as between the FGL and the spacer layer.
    Type: Grant
    Filed: May 26, 2020
    Date of Patent: March 16, 2021
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Zheng Gao, Susumu Okamura, James Mac Freitag
  • Patent number: 10943611
    Abstract: In one embodiment, a write head includes a spin polarization layer (SPL) over a seed layer. A spacer layer is over the SPL. A trailing shield is over the spacer layer. The spacer layer forms a first interface between the spacer layer and the trailing shield and forms a second interface between the spacer layer and the SPL. The first interface has an area larger than an area of the second interface. In another embodiment, a write head includes a SPL over a spacer layer. A capping layer is over the SPL. A trailing shield is over the capping layer. The spacer layer forms a first interface between the spacer layer and the main pole and forms a second interface between the spacer layer and the SPL. The first interface has an area larger than an area of the second interface.
    Type: Grant
    Filed: March 31, 2020
    Date of Patent: March 9, 2021
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: James Mac Freitag, Zheng Gao, Susumu Okamura, Yongchul Ahn, Aron Pentek, Amanda Baer
  • Patent number: 10872627
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.
    Type: Grant
    Filed: August 12, 2020
    Date of Patent: December 22, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Quang Le, Yongchul Ahn, Susumu Okamura, Zheng Gao, Alexander Goncharov, Muhammad Asif Bashir, Petrus Antonius Van Der Heijden, James Mac Freitag
  • Publication number: 20200372929
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.
    Type: Application
    Filed: August 12, 2020
    Publication date: November 26, 2020
    Inventors: Quang LE, Yongchul AHN, Susumu OKAMURA, Zheng GAO, Alexander GONCHAROV, Muhammad ASIF BASHIR, Petrus Antonius VAN DER HEIJDEN, James Mac FREITAG
  • Patent number: 10839833
    Abstract: A spin transfer torque (STT) device is formed on an electrically conductive substrate and includes a ferromagnetic polarizer layer near the substrate, a ferromagnetic free layer, and a nonmagnetic spacer layer between the ferromagnetic polarizer layer and the ferromagnetic free layer. A multilayer structure is located between the substrate and the ferromagnetic polarizer layer. The multilayer structure includes a metal or metal alloy seed layer for the ferromagnetic polarizer layer and an intermediate oxide layer below and in contact with the seed layer. The intermediate oxide layer reflects spin current from the write pole and thus reduces undesirable spin pumping of the ferromagnetic polarizer layer.
    Type: Grant
    Filed: February 27, 2020
    Date of Patent: November 17, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC
    Inventors: James Mac Freitag, Masahiko Hashimoto, Zheng Gao, Susumu Okamura
  • Patent number: 10762917
    Abstract: The present disclosure generally relates to data storage devices, and more specifically, to a magnetic media drive employing a magnetic recording head. The head includes a trailing shield, a main pole, an STO disposed between the trailing shield and the main pole, and a non-magnetic conductive structure adjacent to the main pole and in contact with the STO. The STO includes an FGL and an SPL, and the FGL is disposed between the main pole and the SPL. The FGL includes a side extending over the main pole and at least a portion of the non-magnetic conductive structure. With the FGL disposed proximate to the main pole and over at least a portion of the non-magnetic conductive structure, current crowding and disturbance from the trailing shield are minimized.
    Type: Grant
    Filed: March 28, 2019
    Date of Patent: September 1, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Quang Le, Yongchul Ahn, Susumu Okamura, Zheng Gao, Alexander Goncharov, Muhammad Asif Bashir, Petrus Antonius Van Der Heijden, James Mac Freitag
  • Patent number: 10734013
    Abstract: Spin transfer torque (STT) devices with multilayer seed layers that can be used in magnetic recording and memory are provided. One such STT device includes a substrate, and a stack of layers formed on the substrate, where the stack includes a first seed layer directly on the substrate and including Cr, a second seed layer on the first seed layer and including Ta, a ferromagnetic free layer on the second seed layer; a ferromagnetic polarizing layer, and a nonmagnetic spacer layer between the free layer and the polarizing layer. One such method includes fabricating the STT device.
    Type: Grant
    Filed: February 15, 2019
    Date of Patent: August 4, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Zheng Gao, Masahiko Hashimoto, Susumu Okamura, James Mac Freitag
  • Patent number: 10643643
    Abstract: Embodiments of the present disclosure generally relate to a spin torque oscillator device (STO) including a high damping field generation layer or a damping enhancing capping layer for use in microwave assisted magnetic recording (MAMR) write heads. In one embodiment, a STO device for a MAMR write head includes a spin polarization layer, a spacer layer over the spin polarization layer, and a field generation layer over the spacer layer. The field generation layer has a damping in a range from about 0.5% to about 20%.
    Type: Grant
    Filed: March 19, 2019
    Date of Patent: May 5, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Zheng Gao, James Mac Freitag, Susumu Okamura
  • Publication number: 20200013429
    Abstract: A spin transfer torque (STT) device is formed on an electrically conductive substrate and includes a ferromagnetic free layer near the substrate, a ferromagnetic polarizing layer and a nonmagnetic spacer layer between the free layer and the polarizing layer. A multilayer structure is located between the substrate and the free layer. The multilayer structure includes a metal or metal alloy seed layer for the free layer and an intermediate oxide layer below and in contact with the seed layer. The intermediate oxide layer reflects spin current from the free layer and thus reduces undesirable damping of the oscillation of the free layer's magnetization by the seed layer.
    Type: Application
    Filed: September 16, 2019
    Publication date: January 9, 2020
    Applicants: Western Digital Technologies, Inc., Western Digital Technologies, Inc.
    Inventors: James Mac FREITAG, Susumu OKAMURA, Masahiko HASHIMOTO, Zheng GAO
  • Patent number: 10446175
    Abstract: A spin transfer torque (STT) device is formed on an electrically conductive substrate and includes a ferromagnetic free layer near the substrate, a ferromagnetic polarizing layer and a nonmagnetic spacer layer between the free layer and the polarizing layer. A multilayer structure is located between the substrate and the free layer. The multilayer structure includes a metal or metal alloy seed layer for the free layer and an intermediate oxide layer below and in contact with the seed layer. The intermediate oxide layer reflects spin current from the free layer and thus reduces undesirable damping of the oscillation of the free layer's magnetization by the seed layer.
    Type: Grant
    Filed: May 16, 2017
    Date of Patent: October 15, 2019
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: James Mac Freitag, Susumu Okamura, Masahiko Hashimoto, Zheng Gao
  • Publication number: 20190279666
    Abstract: A spin transfer torque (STT) device is formed on an electrically conductive substrate and includes a ferromagnetic free layer near the substrate, a ferromagnetic polarizing layer and a nonmagnetic spacer layer between the free layer and the polarizing layer. A multilayer structure is located between the substrate and the free layer. The multilayer structure includes a metal or metal alloy seed layer for the free layer and an intermediate oxide layer below and in contact with the seed layer. The intermediate oxide layer reflects spin current from the free layer and thus reduces undesirable damping of the oscillation of the free layer's magnetization by the seed layer.
    Type: Application
    Filed: May 16, 2017
    Publication date: September 12, 2019
    Inventors: James Mac Freitag, Susumu Okamura, Masahiko Hashimoto, Zheng Gao
  • Publication number: 20190259412
    Abstract: Spin transfer torque (STT) devices with multilayer seed layers that can be used in magnetic recording and memory are provided. One such STT device includes a substrate, and a stack of layers formed on the substrate, where the stack includes a first seed layer directly on the substrate and including Cr, a second seed layer on the first seed layer and including Ta, a ferromagnetic free layer on the second seed layer; a ferromagnetic polarizing layer, and a nonmagnetic spacer layer between the free layer and the polarizing layer. One such method includes fabricating the STT device.
    Type: Application
    Filed: February 15, 2019
    Publication date: August 22, 2019
    Inventors: Zheng GAO, Masahiko HASHIMOTO, Susumu OKAMURA, James Mac FREITAG
  • Patent number: 10037772
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole, a seed layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO comprises a spin polarized layer (SPL), an interlayer with fcc structure, and a field generating layer (FGL), in this order in the stacking direction. The FGL comprises a low magnetic flux density interface (LMFDI) layer with bcc structure that directly contacts the interlayer.
    Type: Grant
    Filed: September 25, 2017
    Date of Patent: July 31, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Susumu Okamura, Masashige Sato, Keiichi Nagasaka, Yo Sato
  • Patent number: 9990943
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole and a texture control layer (TCL), a seed control layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO has a crystallographic preferred growth orientation and includes a spin polarized layer (SPL). The TCL may include a Cu layer.
    Type: Grant
    Filed: August 1, 2017
    Date of Patent: June 5, 2018
    Assignee: Western Digital Technologies, Inc.
    Inventors: Susumu Okamura, Yo Sato, Keiichi Nagasaka, Masashige Sato
  • Publication number: 20180025746
    Abstract: A magnetic field-assisted magnetic recording (MAMR) head is provided, which includes a recording main pole, a seed layer, and a spin torque oscillator (STO) positioned over the main pole, in this order, in a stacking direction from a leading side to a trailing side of the recording head. The STO comprises a spin polarized layer (SPL), an interlayer with fcc structure, and a field generating layer (FGL), in this order in the stacking direction. The FGL comprises a low magnetic flux density interface (LMFDI) layer with bcc structure that directly contacts the interlayer.
    Type: Application
    Filed: September 25, 2017
    Publication date: January 25, 2018
    Inventors: Susumu Okamura, Masashige Sato, Keiichi Nagasaka, Yo Sato