Patents by Inventor Kuok San Ho

Kuok San Ho 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: 20240144965
    Abstract: The present disclosure generally relates to spin-orbit torque (SOT) devices comprising a bismuth antimony (BiSb) layer. The SOT devices further comprises a first shield, a BiSb layer disposed over the first shield (S1), a free layer (FL) disposed over the BiSb layer, and a second shield (S2) disposed over the FL. The S1, the FL, and the S2 are disposed at a media facing surface (MFS). The BiSb layer is recessed from the MFS a first distance of about 5 nm to about 20 nm. The FL has a length greater than the first distance. A notch and/or an insulation layer is disposed adjacent to the BiSb layer at the MFS. Current may be configured to flow vertically through the S2 to the FL, and horizontally from the FL to the BiSb layer. Current may be configured to flow vertically through the S2 to the S1.
    Type: Application
    Filed: July 31, 2023
    Publication date: May 2, 2024
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Rohan Babu NAGABHIRAVA, Xiaoyong LIU, Brian R. YORK, Cherngye HWANG, Son T. LE, Randy G. SIMMONS, Kuok San HO, Hisashi TAKANO
  • Publication number: 20240144960
    Abstract: The present disclosure generally relates to a two dimensional magnetic recording (TDMR) spin-orbit torque (SOT) read head comprising bismuth antimony (BiSb) layers. The read head comprises a lower reader comprising a first SOT stack and an upper reader comprising a second SOT stack. The first SOT stack and the second SOT stack each individually comprise a BiSb layer recessed from a media facing surface (MFS) and a free layer exposed at the MFS. The BiSb layers of each SOT stack are recessed from the MFS a distance of about 5 nm to about 20 nm, the distance being less than a length of the free layers. In one embodiment, the lower reader and the upper reader share a current path. In another embodiment, the lower reader and the upper reader have separate current paths.
    Type: Application
    Filed: July 26, 2023
    Publication date: May 2, 2024
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Rohan Babu NAGABHIRAVA, Xiaoyong LIU, Brian R. YORK, Son T. LE, Cherngye HWANG, Kuok San HO, Hisashi TAKANO
  • 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
  • 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: 11882361
    Abstract: Aspects of the present disclosure generally relate to optical devices and related methods that facilitate tilt in camera systems, such as tilt of a lens. In one example, an optical device includes a lens, an image sensor disposed below the lens, a plurality of magnets disposed about the lens, and a plurality of: (1) vertical coil structures coiled in one or more vertical planes and (2) horizontal coil structures coiled in one or more horizontal planes. When power is applied, the coil structures can generate magnetic fields that, in the presence of the magnets, cause relative movement of the coil structures and associated structures. The plurality of vertical coil structures are configured to horizontally move the lens. The plurality of horizontal coil structures are configured to tilt the lens when differing electrical power is applied to at least two of the plurality of horizontal coil structures.
    Type: Grant
    Filed: November 19, 2021
    Date of Patent: January 23, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Rajeev Nagabhirava, Kuok San Ho, Zhigang Bai, Zhanjie Li, Xiaoyong Liu, Daniele Mauri
  • Patent number: 11875827
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) devices. The SOT devices each comprise a non-magnetic layer, a free layer disposed in contact with the non-magnetic layer, and a bismuth antimony (BiSb) layer disposed over the free layer. The non-magnetic layer has a thickness of about 0.5 nm to about 2 nm. The BiSb layer has a thickness of about 5 nm to about 10 nm. The BiSb layer and the free layer have collective thickness between about 5 nm to about 20 nm. By reducing the thickness of the non-magnetic layer and BiSb layer, a read gap of each SOT device is reduced while enabling large inverse spin Hall angles and high signal-to-noise ratios.
    Type: Grant
    Filed: March 25, 2022
    Date of Patent: January 16, 2024
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Brian R. York, Xiaoyong Liu, Son T. Le, Cherngye Hwang, Michael A. Gribelyuk, Xiaoyu Xu, Kuok San Ho, Hisashi Takano, Julian Sasaki, Huy H. Ho, Khang H. D. Nguyen, Nam Hai Pham
  • Publication number: 20240006109
    Abstract: The present disclosure generally relates to spin-orbit torque (SOT) device comprising a first bismuth antimony (BiSb) layer having a (001) orientation. The SOT device comprises a first BiSb layer having a (001) orientation and a second BiSb layer having a (012) orientation. The first BiSb layer having a (001) orientation is formed by depositing an amorphous material selected from the group consisting of: B, Al, Si, SiN, Mg, Ti, Sc, V, Cr, Mn, Y, Zr, Nb, AlN, C, Ge, and combinations thereof, on a substrate, exposing the amorphous material to form an amorphous oxide surface on the amorphous material, and depositing the first BiSb layer on the amorphous oxide surface. By utilizing a first BiSb layer having a (001) orientation and a second BiSb having a (012) orientation, the signal through the SOT device is balanced and optimized to match through both the first and second BiSb layers.
    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, Randy G. SIMMONS, Kuok San HO, Hisashi TAKANO
  • 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: 20230419990
    Abstract: The present disclosure generally relates to a bismuth antimony (BiSb) based STO (spin torque oscillator) sensor. The STO sensor comprises a SOT device and a magnetic tunnel junction (MTJ) structure. By utilizing a BiSb layer within the SOT device, a larger spin Hall angle (SHA) can be achieved, thereby improving the efficiency and reliability of the STO sensor.
    Type: Application
    Filed: September 11, 2023
    Publication date: December 28, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: Xiaoyong LIU, Zhanjie LI, Quang LE, Brian R. YORK, Cherngye HWANG, Kuok San HO, Hisashi TAKANO
  • 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: 11783853
    Abstract: The present disclosure generally relates to a bismuth antimony (BiSb) based STO (spin torque oscillator) sensor. The STO sensor comprises a SOT device and a magnetic tunnel junction (MTJ) structure. By utilizing a BiSb layer within the SOT device, a larger spin Hall angle (SHA) can be achieved, thereby improving the efficiency and reliability of the STO sensor.
    Type: Grant
    Filed: May 31, 2022
    Date of Patent: October 10, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: Xiaoyong Liu, Zhanjie Li, Quang Le, Brian R. York, Cherngye Hwang, Kuok San Ho, Hisashi Takano
  • Patent number: 11776567
    Abstract: The present disclosure generally relates to spin-orbital torque (SOT) differential reader designs. The SOT differential reader is a multi-terminal device comprising a first seed layer, a first spin hall effect (SHE) layer, a first interlayer, a first free layer, a gap layer, a second seed layer, a second SHE layer, a second free layer, and a second interlayer. The gap layer is disposed between the first SHE layer and the second SHE layer. The materials and dimensions used for the first and second seed layers, the first and second interlayers, and the first and second SHE layers affect the resulting spin hall voltage converted from spin current injected from the first free layer and the second free layer, as well as the ability to tune the first and second SHE layers. Moreover, the SOT differential reader improves reader resolution without decreasing the shield-to-shield spacing (i.e., read-gap).
    Type: Grant
    Filed: August 5, 2021
    Date of Patent: October 3, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: Cherngye Hwang, Xiaoyong Liu, Quang Le, Kuok San Ho, Hisashi Takano, Brian R. York
  • Publication number: 20230306993
    Abstract: The present disclosure generally relate to spin-orbit torque (SOT) devices. The SOT devices each comprise a non-magnetic layer, a free layer disposed in contact with the non-magnetic layer, and a bismuth antimony (BiSb) layer disposed over the free layer. The non-magnetic layer has a thickness of about 0.5 nm to about 2 nm. The BiSb layer has a thickness of about 5 nm to about 10 nm. The BiSb layer and the free layer have collective thickness between about 5 nm to about 20 nm. By reducing the thickness of the non-magnetic layer and BiSb layer, a read gap of each SOT device is reduced while enabling large inverse spin Hall angles and high signal-to-noise ratios.
    Type: Application
    Filed: March 25, 2022
    Publication date: September 28, 2023
    Inventors: Quang LE, Brian R. YORK, Xiaoyong LIU, Son T. LE, Cherngye HWANG, Michael A. GRIBELYUK, Xiaoyu XU, Kuok San HO, Hisashi TAKANO, Julian SASAKI, Huy H. HO, Khang H. D. NGUYEN, Nam Hai PHAM
  • 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: 11694713
    Abstract: A spin-orbit torque (SOT) magnetic tunnel junction (MTJ) device includes a substrate, a buffer layer formed over the substrate, and a bismuth antimony (BiSb) layer formed over the buffer layer, the BiSb layer having a (012) orientation. In certain embodiments, the SOT MTJ device is part of a microwave assisted magnetic recording (MAMR) write head. In certain embodiments, the SOT MTJ device is part of a magnetoresistive random access memory (MRAM) device.
    Type: Grant
    Filed: November 20, 2020
    Date of Patent: July 4, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Cherngye Hwang, Brian R. York, Thao A. Nguyen, Zheng Gao, Kuok San Ho, Pham Nam Hai
  • Publication number: 20230197132
    Abstract: The present disclosure generally relates to spin-orbit torque (SOT) magnetic tunnel junction (MTJ) devices comprising a doped bismuth antimony (BiSbE) layer having a (012) orientation. The devices may include magnetic write heads, read heads, or MRAM devices. The dopant in the BiSbE layer enhances the (012) orientation. The BiSbE layer may be formed on a texturing layer to ensure the (012) orientation, and a migration barrier may be formed over the BiSbE layer to ensure the antimony does not migrate through the structure and contaminate other layers. A buffer layer and interlayer may also be present. 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 inhibit antimony (Sb) migration within the doped BiSbE layer and enhance uniformity of the doped BiSbE layer while further promoting the (012) orientation of the doped BiSbE layer.
    Type: Application
    Filed: June 30, 2022
    Publication date: June 22, 2023
    Applicant: Western Digital Technologies, Inc.
    Inventors: Quang LE, Cherngye HWANG, Brian R. YORK, Randy G. SIMMONS, Xiaoyong LIU, Kuok San HO, Hisashi TAKANO, Michael A. GRIBELYUK, Xiaoyu XU
  • Patent number: 11682418
    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 main pole at a media facing surface (MFS), a trailing shield at the MFS, and a heavy metal layer disposed between the main pole and the trailing shield at the MFS. Spin-orbit torque (SOT) is generated from the heavy metal layer and transferred to a surface of the main pole as a current passes through the heavy metal layer in a cross-track direction. The SOT executes a torque on the surface magnetization of the main pole, which reduces the magnetic flux shunting from the main pole to the trailing shield. With the reduced magnetic flux shunting from the main pole to the trailing shield, write-ability is improved.
    Type: Grant
    Filed: July 19, 2022
    Date of Patent: June 20, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: Suping Song, Zhanjie Li, Michael Kuok San Ho, Quang Le, Alexander M. Zeltser
  • Publication number: 20230186946
    Abstract: The present disclosure is generally related to a tape drive including a tape head configured to read shingled data on a tape. The tape head comprises a first module head assembly aligned with a second module head assembly. Both the first and second module head assemblies comprises a plurality of data heads. Each data head comprises a write head, a first read head aligned with the write head, a second read head offset from the first read head in both a cross-track direction and a down-track direction, and a third read head offset from the first and/or second read heads in the cross-track and down-track directions. By utilizing three read heads within each data head, data can be read from a tape that has experienced tape dimensional stability, as at least one read head will be near a center of each data track of the tape.
    Type: Application
    Filed: December 15, 2021
    Publication date: June 15, 2023
    Inventors: Quang LE, Xiaoyong LIU, Hongquan JIANG, Cherngye HWANG, Kuok San HO, Hisashi TAKANO
  • Patent number: 11670329
    Abstract: The present disclosure is generally related to a tape drive including a tape head configured to read shingled data on a tape. The tape head comprises a first module head assembly aligned with a second module head assembly. Both the first and second module head assemblies comprises a plurality of data heads. Each data head comprises a write head, a first read head aligned with the write head, a second read head offset from the first read head in both a cross-track direction and a down-track direction, and a third read head offset from the first and/or second read heads in the cross-track and down-track directions. By utilizing three read heads within each data head, data can be read from a tape that has experienced tape dimensional stability, as at least one read head will be near a center of each data track of the tape.
    Type: Grant
    Filed: December 15, 2021
    Date of Patent: June 6, 2023
    Assignee: Western Digital Technologies, Inc.
    Inventors: Quang Le, Xiaoyong Liu, Hongquan Jiang, Cherngye Hwang, Kuok San Ho, Hisashi Takano