Patents by Inventor Yongchul Ahn

Yongchul Ahn 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).

  • 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: 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: 20230030248
    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: Application
    Filed: July 28, 2021
    Publication date: February 2, 2023
    Inventors: Susumu OKAMURA, Christian KAISER, Xinjiang SHEN, Yongchul AHN, James Mac FREITAG
  • Publication number: 20230027086
    Abstract: A spin-orbit torque (SOT) magnetic tunnel junction (MTJ) device includes a substrate, a seed layer over the substrate, and a bismuth antimony (BiSb) layer having (0120) orientation on the seed layer. The seed layer includes a silicide layer and a surface control layer. The silicide layer includes a material of NiSi, NiFeSi, NiFeTaSi, NiCuSi, CoSi, CoFeSi, CoFeTaSi, CoCuSi, or combinations thereof. The surface control layer includes a material of NiFe, NiFeTa, NiTa, NiW, NiFeW, NiCu, NiCuM, NiFeCu, CoTa, CoFeTa, NiCoTa, Co, CoM, CoNiM, CoNi, NiSi, CoSi, NiCoSi, Cu, CuAgM, CuM, or combinations thereof, in which M is Fe, Cu, Co, Ta, Ag, Ni, Mn, Cr, V, Ti, or Si.
    Type: Application
    Filed: September 28, 2022
    Publication date: January 26, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Cherngye HWANG, Brian R. YORK, Andrew CHEN, Thao A. NGUYEN, Yongchul AHN, Xiaoyong LIU, Hongquan JIANG, Zheng GAO, Kuok San HO
  • Patent number: 11489108
    Abstract: A spin-orbit torque (SOT) magnetic tunnel junction (MTJ) device includes a substrate, a seed layer over the substrate, and a bismuth antimony (BiSb) layer having (0120) orientation on the seed layer. The seed layer includes a silicide layer and a surface control layer. The silicide layer includes a material of NiSi, NiFeSi, NiFeTaSi, NiCuSi, CoSi, CoFeSi, CoFeTaSi, CoCuSi, or combinations thereof. The surface control layer includes a material of NiFe, NiFeTa, NiTa, NiW, NiFeW, NiCu, NiCuM, NiFeCu, CoTa, CoFeTa, NiCoTa, Co, CoM, CoNiM, CoNi, NiSi, CoSi, NiCoSi, Cu, CuAgM, CuM, or combinations thereof, in which M is Fe, Cu, Co, Ta, Ag, Ni, Mn, Cr, V, Ti, or Si.
    Type: Grant
    Filed: April 28, 2020
    Date of Patent: November 1, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Cherngye Hwang, Brian R. York, Andrew Chen, Thao A. Nguyen, Yongchul Ahn, Xiaoyong Liu, Hongquan Jiang, Zheng Gao, Kuok San Ho
  • Patent number: 11393516
    Abstract: An apparatus is provided that includes an array including m rows and n columns of nodes. Each column of nodes is coupled to one of n first conductive lines, and each row of nodes is coupled to one of m second conductive lines. Each node of the m rows and n columns of nodes includes a spin orbit torque-based spin torque oscillator circuit configured to oscillate at a corresponding intrinsic frequency. The spin orbit torque-based spin torque oscillator circuits are configured to generate m output signals at the m second conductive lines upon application of n input signals to corresponding n first conductive lines. The n input signals correspond to an n-element input vector, and each input signal includes a corresponding input signal frequency. Each of the m output signals include frequency domain components at the input signal frequencies.
    Type: Grant
    Filed: February 10, 2021
    Date of Patent: July 19, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Thao A. Nguyen, Michael Ho, Xiaoyong Liu, Zhigang Bai, Zhanjie Li, Quang Le, Yongchul Ahn, Hongquan Jiang
  • Publication number: 20220122647
    Abstract: An apparatus is provided that includes an array including m rows and n columns of nodes. Each column of nodes is coupled to one of n first conductive lines, and each row of nodes is coupled to one of m second conductive lines. Each node of the m rows and n columns of nodes includes a spin orbit torque-based spin torque oscillator circuit configured to oscillate at a corresponding intrinsic frequency. The spin orbit torque-based spin torque oscillator circuits are configured to generate m output signals at the m second conductive lines upon application of n input signals to corresponding n first conductive lines. The n input signals correspond to an n-element input vector, and each input signal includes a corresponding input signal frequency. Each of the m output signals include frequency domain components at the input signal frequencies.
    Type: Application
    Filed: February 10, 2021
    Publication date: April 21, 2022
    Applicant: Western Digital Technologies, Inc.
    Inventors: Thao A. Nguyen, Michael Ho, Xiaoyong Liu, Zhigang Bai, Zhanjie Li, Quang Le, Yongchul Ahn, Hongquan Jiang
  • Patent number: 11283008
    Abstract: An apparatus is provided that includes a magnetic tunnel junction, a magnetic assist layer coupled to the magnetic tunnel junction, a non-magnetic layer disposed between the free layer and the magnetic assist layer, and a spin Hall effect layer coupled to the magnetic assist layer. The magnetic tunnel junction includes a free layer in a plane, the free layer including a switchable magnetization direction perpendicular to the plane. The magnetic assist layer includes a magnetization direction parallel to the plane and free to rotate about an axis perpendicular to the plane.
    Type: Grant
    Filed: February 10, 2021
    Date of Patent: March 22, 2022
    Assignee: Western Digital Technologies, Inc.
    Inventors: Thao A. Nguyen, Michael Ho, Zhigang Bai, Xiaoyong Liu, Zhanjie Li, Yongchul Ahn, Hongquan Jiang, Quang Le
  • Publication number: 20220069202
    Abstract: An apparatus is provided that includes a magnetic tunnel junction, a magnetic assist layer coupled to the magnetic tunnel junction, a non-magnetic layer disposed between the free layer and the magnetic assist layer, and a spin Hall effect layer coupled to the magnetic assist layer. The magnetic tunnel junction includes a free layer in a plane, the free layer including a switchable magnetization direction perpendicular to the plane. The magnetic assist layer includes a magnetization direction parallel to the plane and free to rotate about an axis perpendicular to the plane.
    Type: Application
    Filed: February 10, 2021
    Publication date: March 3, 2022
    Applicant: Western Digital Technologies, Inc.
    Inventors: Thao A. Nguyen, Michael Ho, Zhigang Bai, Xiaoyong Liu, Zhanjie Li, Yongchul Ahn, Hongquan Jiang, Quang Le
  • Publication number: 20220044103
    Abstract: An apparatus is provided that includes an array including n rows and m columns of nodes, each row of nodes coupled to one of n first conductive lines, each column of nodes coupled to one of m second conductive lines, each node of the n rows and m columns of nodes including a spin orbit torque MRAM non-volatile memory cell configured to store a corresponding weight of an n×m array of weights each having a first weight value or a second weight value, and a control circuit configured to apply n input voltages each having a first input value or a second input value to corresponding n first conductive lines, the n input voltages corresponding to an n-element input vector. The spin orbit torque MRAM non-volatile memory cells are configured to generate m output currents at the m second conductive lines upon application of the n input voltages. The m output currents corresponding to a result of multiplying the input vector by the n×m array of weights.
    Type: Application
    Filed: February 10, 2021
    Publication date: February 10, 2022
    Applicant: Western Digital Technologies, Inc.
    Inventors: Thao A. Nguyen, Michael Ho, Zhigang Bai, Xiaoyong Liu, Zhanjie Li, Yongchul Ahn, Hongquan Jiang, Quang Le
  • Publication number: 20210336127
    Abstract: A spin-orbit torque (SOT) magnetic tunnel junction (MTJ) device includes a substrate, a seed layer over the substrate, and a bismuth antimony (BiSb) layer having (0120) orientation on the seed layer. The seed layer includes a silicide layer and a surface control layer. The silicide layer includes a material of NiSi, NiFeSi, NiFeTaSi, NiCuSi, CoSi, CoFeSi, CoFeTaSi, CoCuSi, or combinations thereof. The surface control layer includes a material of NiFe, NiFeTa, NiTa, NiW, NiFeW, NiCu, NiCuM, NiFeCu, CoTa, CoFeTa, NiCoTa, Co, CoM, CoNiM, CoNi, NiSi, CoSi, NiCoSi, Cu, CuAgM, CuM, or combinations thereof, in which M is Fe, Cu, Co, Ta, Ag, Ni, Mn, Cr, V, Ti, or Si.
    Type: Application
    Filed: April 28, 2020
    Publication date: October 28, 2021
    Inventors: Quang LE, Cherngye HWANG, Brian R. YORK, Andrew CHEN, Thao A. NGUYEN, Yongchul AHN, Xiaoyong LIU, Hongquan JIANG, Zheng GAO, Kuok San HO
  • 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: 10839845
    Abstract: Magnetic sensors with effectively shaped side shields and their fabrication processes are provided. One such process includes depositing sensor materials on a substrate, shaping the sensor materials to form a stripe height of the magnetic sensor, shaping the sensor materials to form a track width of the magnetic sensor, depositing side shield materials on the shaped sensor materials, shaping the side shield materials such that a resulting side shield extends further than the stripe height, depositing an insulator layer on the shaped side shield materials, and shaping the insulator layer.
    Type: Grant
    Filed: July 9, 2019
    Date of Patent: November 17, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Quang Le, Yongchul Ahn, Xiaoyong Liu, Jui-Lung Li, Hongquan Jiang
  • 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: 10720570
    Abstract: Magnetic sensors using spin Hall effect and methods for fabricating same are provided. One such magnetic sensor includes a spin Hall layer including an electrically conductive, non-magnetic material, a magnetic free layer adjacent to the spin Hall layer, a pair of push terminals configured to enable an electrical current to pass through the magnetic free layer and the spin Hall layer in a direction that is perpendicular to a plane of the free and spin Hall layers, and a pair of sensing terminals configured to sense a voltage when the electrical current passes through the magnetic free layer and the spin Hall layer, where each of the push and sensing terminals is electrically isolated from the other terminals.
    Type: Grant
    Filed: November 29, 2017
    Date of Patent: July 21, 2020
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Quang Le, David John Seagle, Xiaoyong Liu, Daniele Mauri, Yongchul Ahn, Hongquan Jiang, Guangli Liu, David Patrick Druist, Jui-Lung Li
  • Publication number: 20190333534
    Abstract: Magnetic sensors with effectively shaped side shields and their fabrication processes are provided. One such process includes depositing sensor materials on a substrate, shaping the sensor materials to form a stripe height of the magnetic sensor, shaping the sensor materials to form a track width of the magnetic sensor, depositing side shield materials on the shaped sensor materials, shaping the side shield materials such that a resulting side shield extends further than the stripe height, depositing an insulator layer on the shaped side shield materials, and shaping the insulator layer.
    Type: Application
    Filed: July 9, 2019
    Publication date: October 31, 2019
    Inventors: Quang Le, Yongchul Ahn, Xiaoyong Liu, Jui-Lung Li, Hongquan Jiang
  • Patent number: 10381032
    Abstract: Magnetic sensors with effectively shaped side shields and their fabrication processes are provided. One such sensor includes a substrate, a sensor stack disposed on the substrate and having a stripe height, where the sensor stack further includes a front edge disposed at an air bearing surface (ABS) of the magnetic sensor, a back edge opposite of the front edge, and two side edges, and a side shield adjacent to each of the two side edges of the sensor stack, each side shield having a side shield height defined as a distance from the ABS to a back edge of the side shields, where the side shield height is greater than the stripe height, and where substantially no residue from materials used to form the side shield are disposed at the back edge of the sensor stack.
    Type: Grant
    Filed: January 12, 2018
    Date of Patent: August 13, 2019
    Assignee: WESTERN DIGITAL TECHNOLOGIES, INC.
    Inventors: Quang Le, Yongchul Ahn, Xiaoyong Liu, Jui-Lung Li, Hongquan Jiang
  • Publication number: 20190221232
    Abstract: Magnetic sensors with effectively shaped side shields and their fabrication processes are provided. One such sensor includes a substrate, a sensor stack disposed on the substrate and having a stripe height, where the sensor stack further includes a front edge disposed at an air bearing surface (ABS) of the magnetic sensor, a back edge opposite of the front edge, and two side edges, and a side shield adjacent to each of the two side edges of the sensor stack, each side shield having a side shield height defined as a distance from the ABS to a back edge of the side shields, where the side shield height is greater than the stripe height, and where substantially no residue from materials used to form the side shield are disposed at the back edge of the sensor stack.
    Type: Application
    Filed: January 12, 2018
    Publication date: July 18, 2019
    Inventors: Quang Le, Yongchul Ahn, Xiaoyong Liu, Jui-Lung Li, Hongquan Jiang