Patents by Inventor Guohan Hu

Guohan Hu 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: 10686123
    Abstract: A multilayered magnetic free layer structure is provided that includes a first magnetic free layer and a second magnetic free layer separated by a non-magnetic layer in which the second magnetic free layer has higher magnetic damping (greater than 0.01) as compared with the first magnetic free layer. Such a multilayered magnetic free layer structure substantially reduces the switching current needed to reorient the magnetization of the magnetic free layers. The higher magnetic damping value of the second magnetic free layer as compared to the first magnetic free layer improves the switching speed of the magnetic free layers and thus reduces, and even eliminates, write errors.
    Type: Grant
    Filed: August 16, 2018
    Date of Patent: June 16, 2020
    Assignee: International Business Machines Corporation
    Inventors: Guohan Hu, Daniel Worledge
  • Publication number: 20200152699
    Abstract: A multilayered magnetic free layer structure is provided that includes a first magnetic free layer and a second magnetic free layer separated by a non-magnetic layer in which the second magnetic free layer has a lower perpendicular magnetic anisotropy field, Hk, as compared with the first magnetic free layer. The multilayered magnetic free layer structure of the present application substantially reduces the switching current needed to reorient the magnetization of the two magnetic free layers. The lower Hk value of the second magnetic free layer as compared to the first magnetic free layer improves the switching speed of the second magnetic free layer and thus reduces, and even eliminates, write errors.
    Type: Application
    Filed: November 8, 2018
    Publication date: May 14, 2020
    Inventors: Daniel Worledge, Guohan Hu
  • Patent number: 10600566
    Abstract: A planar magnetic structure includes a closed loop structure having a plurality of core segments divided into at least two sets. A coil is formed about one or more core segments. A first antiferromagnetic layer is formed on a first set of core segments, and a second antiferromagnetic layer is formed on a second set of core segments. The first and second antiferromagnetic layers include different blocking temperatures and have an easy axis pinning a magnetic moment in two different directions, wherein when current flows through the coil, the magnetic moments rotate to form a closed magnetic loop in the closed loop structure.
    Type: Grant
    Filed: October 13, 2016
    Date of Patent: March 24, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Guohan Hu, Naigang Wang
  • Publication number: 20200083438
    Abstract: A method for forming a memory device that includes providing a free layer of an alloy of cobalt (Co), iron (Fe) and boron (B) overlying a reference layer; and forming metal layer comprising a boron (B) sink composition atop the free layer. Boron (B) may be diffused from the free layer to the metal layer comprising the boron sink composition. At least a portion of the metal layer including the boron (B) sink composition is removed. A metal oxide is formed atop the free layer. The free layer may be a crystalline cobalt and iron alloy. An interface between the metal oxide and free layer can provide perpendicular magnetic anisotropy character.
    Type: Application
    Filed: November 18, 2019
    Publication date: March 12, 2020
    Inventors: Stephen L. Brown, Guohan Hu, Jonathan Z. Sun, Daniel C. Worledge
  • Patent number: 10580971
    Abstract: A method includes depositing a magnetic track layer on a seed layer, depositing an alloy layer on the magnetic track layer, depositing a tunnel barrier layer on the alloy layer, depositing a pinning layer on the tunnel barrier layer, depositing a synthetic antiferromagnetic layer spacer on the pinning layer, depositing a pinned layer on the synthetic antiferromagnetic spacer layer and depositing an antiferromagnetic layer on the pinned layer, and another method includes depositing an antiferromagnetic layer on a seed layer, depositing a pinned layer on the antiferromagnetic layer, depositing a synthetic antiferromagnetic layer spacer on the pinned layer, depositing a pinning layer on the synthetic antiferromagnetic layer spacer, depositing a tunnel barrier layer on the pinning layer, depositing an alloy layer on the tunnel barrier layer and depositing a magnetic track layer on alloy layer.
    Type: Grant
    Filed: February 9, 2018
    Date of Patent: March 3, 2020
    Assignees: INTERNATIONAL BUSINESS MACHINES CORPORATION, INDUSTRIAL TECHNOLOGY RESEARCH
    Inventors: Guohan Hu, Cheng-Wei Chien
  • Publication number: 20200066791
    Abstract: A double magnetic tunnel junction includes a bottom reference layer having a first fixed magnetization and a first thickness and formed from at least one material. A first tunnel barrier is on the bottom reference layer. A free layer is on the first tunnel barrier and has a changeable magnetization. A second tunnel barrier is on the free layer. A multilayered top reference layer is formed on the second tunnel barrier having a second fixed magnetization that is opposite to the first fixed magnetization and a second thickness that is smaller than the first thickness, and equal to or greater than the third thickness.
    Type: Application
    Filed: October 30, 2019
    Publication date: February 27, 2020
    Inventors: Guohan Hu, Younghyun Kim, Jeong-Heon Park, Daniel Worledge
  • Publication number: 20200058440
    Abstract: A planar magnetic structure includes a closed loop structure having a plurality of core segments divided into at least two sets. A coil is formed about one or more core segments. A first antiferromagnetic layer is formed on a first set of core segments, and a second antiferromagnetic layer is formed on a second set of core segments. The first and second antiferromagnetic layers include different blocking temperatures and have an easy axis pinning a magnetic moment in two different directions, wherein when current flows through the coil, the magnetic moments rotate to form a closed magnetic loop in the closed loop structure.
    Type: Application
    Filed: October 28, 2019
    Publication date: February 20, 2020
    Inventors: Guohan Hu, Naigang Wang
  • Publication number: 20200058845
    Abstract: A multilayered magnetic free layer structure is provided that includes a first magnetic free layer and a second magnetic free layer separated by a non-magnetic layer in which the second magnetic free layer has higher magnetic damping (greater than 0.01) as compared with the first magnetic free layer. Such a multilayered magnetic free layer structure substantially reduces the switching current needed to reorient the magnetization of the magnetic free layers. The higher magnetic damping value of the second magnetic free layer as compared to the first magnetic free layer improves the switching speed of the magnetic free layers and thus reduces, and even eliminates, write errors.
    Type: Application
    Filed: August 16, 2018
    Publication date: February 20, 2020
    Inventors: Guohan Hu, Daniel Worledge
  • Patent number: 10553781
    Abstract: A method for forming a memory device that includes providing a free layer of an alloy of cobalt (Co), iron (Fe) and boron (B) overlying a reference layer; and forming metal layer comprising a boron (B) sink composition atop the free layer. Boron (B) may be diffused from the free layer to the metal layer comprising the boron sink composition. At least a portion of the metal layer including the boron (B) sink composition is removed. A metal oxide is formed atop the free layer. The free layer may be a crystalline cobalt and iron alloy. An interface between the metal oxide and free layer can provide perpendicular magnetic anisotropy character.
    Type: Grant
    Filed: March 23, 2017
    Date of Patent: February 4, 2020
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Stephen L. Brown, Guohan Hu, Jonathan Z. Sun, Daniel C. Worledge
  • Publication number: 20190392988
    Abstract: A planar magnetic structure includes a closed loop structure having a plurality of core segments divided into at least two sets. A coil is formed about one or more core segments. A first antiferromagnetic layer is formed on a first set of core segments, and a second antiferromagnetic layer is formed on a second set of core segments. The first and second antiferromagnetic layers include different blocking temperatures and have an easy axis pinning a magnetic moment in two different directions, wherein when current flows through the coil, the magnetic moments rotate to form a closed magnetic loop in the closed loop structure.
    Type: Application
    Filed: September 4, 2019
    Publication date: December 26, 2019
    Inventors: Guohan Hu, Naigang Wang
  • Patent number: 10510391
    Abstract: Embodiments of the invention are directed to a magnetic tunnel junction (MTJ) storage element that includes a reference layer, a tunnel barrier and a free layer on an opposite side of the tunnel barrier layer from the reference layer. The reference layer has a fixed magnetization direction. The free layer includes a first region, a second region and a third region. The third region is formed from a third material that is configured to magnetically couple the first region and the second region. The first region is formed from a first material having a first predetermined magnetic moment, and the second region is formed from a second material having a second predetermined magnetic moment. The first predetermined magnetic moment is lower that the second predetermined magnetic moment.
    Type: Grant
    Filed: November 3, 2017
    Date of Patent: December 17, 2019
    Assignees: INTERNATIONAL BUSINESS MACHINES CORPORATION, SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Guohan Hu, Jeong-Heon Park, Daniel C. Worledge
  • Patent number: 10510390
    Abstract: Embodiments of the invention are directed to a magnetic tunnel junction (MTJ) storage element that includes a reference layer, a tunnel barrier and a free layer on an opposite side of the tunnel barrier layer from the reference layer. The reference layer has a fixed magnetization direction. The free layer includes a first region, a second region and a third region. The third region is formed from a third material that is configured to magnetically couple the first region and the second region. The first region is formed from a first material having a first predetermined magnetic moment, and the second region is formed from a second material having a second predetermined magnetic moment. The first predetermined magnetic moment is lower that the second predetermined magnetic moment.
    Type: Grant
    Filed: June 7, 2017
    Date of Patent: December 17, 2019
    Assignees: INTERNATIONAL BUSINESS MACHINES CORPORATION, SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Guohan Hu, Jeong-Heon Park, Daniel C. Worledge
  • Patent number: 10468455
    Abstract: Double magnetic tunnel junctions and methods of forming the same include a bottom reference layer having a first fixed magnetization and a first thickness. A first tunnel barrier is formed on the bottom reference layer. A free layer is formed on the first tunnel barrier and has a changeable magnetization. A second tunnel barrier is formed on the free layer. A top reference layer is formed on the second tunnel barrier and has a second fixed magnetization that is opposite to the first fixed magnetization and a second thickness that is significantly smaller than the first thickness.
    Type: Grant
    Filed: April 12, 2016
    Date of Patent: November 5, 2019
    Assignees: INTERNATIONAL BUSINESS MACHINES CORPORATION, SAMSUNG ELECTRONICS, CO., LTD.
    Inventors: Guohan Hu, Younghyun Kim, Jeong-Heon Park, Daniel Worledge
  • Patent number: 10453509
    Abstract: Embodiments of the invention are directed to a magnetic tunnel junction (MTJ) storage element that includes a reference layer, a tunnel barrier and a free layer on an opposite side of the tunnel barrier layer from the reference layer. The reference layer has a fixed magnetization direction. The free layer includes a first region, a second region and a third region. The third region is formed from a third material that is configured to magnetically couple the first region and the second region. The first region is formed from a first material having a first predetermined magnetic moment, and the second region is formed from a second material having a second predetermined magnetic moment. The first predetermined magnetic moment is lower that the second predetermined magnetic moment.
    Type: Grant
    Filed: November 3, 2017
    Date of Patent: October 22, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Guohan Hu, Daniel C. Worledge
  • Publication number: 20190288186
    Abstract: Techniques relate to forming a magnetic tunnel junction (MTJ). A synthetic antiferromagnetic reference layer is adjacent to a tunnel barrier layer. The synthetic antiferromagnetic reference layer includes a first magnetic layer, a second magnetic layer, and a reference spacer layer sandwiched between the first magnetic layer and the second magnetic layer. A magnetic free layer is adjacent to the tunnel barrier layer so as to be opposite the synthetic antiferromagnetic reference layer. The synthetic antiferromagnetic reference layer has a thickness of at least one of 3 nanometers (nm), 4 nm, and 3-4 nm.
    Type: Application
    Filed: May 13, 2019
    Publication date: September 19, 2019
    Inventors: Guohan Hu, Younghyun Kim, Daniel C. Worledge
  • Publication number: 20190244647
    Abstract: Embodiments of the invention are directed to a magnetic tunnel junction (MTJ) storage element that includes a reference layer, a tunnel barrier and a free layer on an opposite side of the tunnel barrier layer from the reference layer. The reference layer has a fixed magnetization direction. The free layer includes a first region, a second region and a third region. The third region is formed from a third material that is configured to magnetically couple the first region and the second region. The first region is formed from a first material having a first predetermined magnetic moment, and the second region is formed from a second material having a second predetermined magnetic moment. The first predetermined magnetic moment is lower that the second predetermined magnetic moment.
    Type: Application
    Filed: April 17, 2019
    Publication date: August 8, 2019
    Inventors: Guohan Hu, Daniel C. Worledge
  • Patent number: 10374145
    Abstract: A method for forming a memory device that includes providing a free layer of an alloy of cobalt (Co), iron (Fe) and boron (B) overlying a reference layer; and forming metal layer comprising a boron (B) sink composition atop the free layer. Boron (B) may be diffused from the free layer to the metal layer comprising the boron sink composition. At least a portion of the metal layer including the boron (B) sink composition is removed. A metal oxide is formed atop the free layer. The free layer may be a crystalline cobalt and iron alloy. An interface between the metal oxide and free layer can provide perpendicular magnetic anisotropy character.
    Type: Grant
    Filed: October 14, 2015
    Date of Patent: August 6, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Stephen L. Brown, Guohan Hu, Jonathan Z. Sun, Daniel C. Worledge
  • Patent number: 10361361
    Abstract: Techniques relate to forming a magnetic tunnel junction (MTJ). A synthetic antiferromagnetic reference layer is adjacent to a tunnel barrier layer. The synthetic antiferromagnetic reference layer includes a first magnetic layer, a second magnetic layer, and a reference spacer layer sandwiched between the first magnetic layer and the second magnetic layer. A magnetic free layer is adjacent to the tunnel barrier layer so as to be opposite the synthetic antiferromagnetic reference layer. The synthetic antiferromagnetic reference layer has a thickness of at least one of 3 nanometers (nm), 4 nm, and 3-4 nm.
    Type: Grant
    Filed: April 8, 2016
    Date of Patent: July 23, 2019
    Assignees: INTERNATIONAL BUSINESS MACHINES CORPORATION, SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Guohan Hu, Younghyun Kim, Daniel C. Worledge
  • Patent number: 10347827
    Abstract: A method of making a spin-torque transfer magnetic random access memory device (STT MRAM) device includes forming a tunnel barrier layer on a reference layer; forming a free layer on the tunnel barrier layer, the free layer comprising a cobalt iron boron (CoFeB) alloy layer and an iron (Fe) layer; and performing a sputtering process to form a metal oxide layer on the Fe layer.
    Type: Grant
    Filed: April 4, 2018
    Date of Patent: July 9, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventor: Guohan Hu
  • Patent number: 10332576
    Abstract: Embodiments of the invention are directed to a magnetic tunnel junction (MTJ) storage element that includes a reference layer, a tunnel barrier and a free layer on an opposite side of the tunnel barrier layer from the reference layer. The reference layer has a fixed magnetization direction. The free layer includes a first region, a second region and a third region. The third region is formed from a third material that is configured to magnetically couple the first region and the second region. The first region is formed from a first material having a first predetermined magnetic moment, and the second region is formed from a second material having a second predetermined magnetic moment. The first predetermined magnetic moment is lower that the second predetermined magnetic moment.
    Type: Grant
    Filed: June 7, 2017
    Date of Patent: June 25, 2019
    Assignee: INTERNATIONAL BUSINESS MACHINES CORPORATION
    Inventors: Guohan Hu, Daniel C. Worledge