Patents by Inventor Yiming Huai

Yiming Huai 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: 7742328
    Abstract: A magnetic memory cell and a magnetic memory incorporating the cell are described. The magnetic memory cell includes at least one magnetic element and at least one non-planar selection device. The magnetic element(s) are programmable using write current(s) driven through the magnetic element. The magnetic memory may include a plurality of magnetic storage cells, a plurality of bit lines corresponding to the plurality of magnetic storage cells, and a plurality of source lines corresponding to the plurality of magnetic storage cells.
    Type: Grant
    Filed: June 15, 2007
    Date of Patent: June 22, 2010
    Assignee: Grandis, Inc.
    Inventors: Eugene Chen, Yiming Huai, Alexander A. G. Driskill-Smith
  • Patent number: 7738287
    Abstract: A method and system for providing a magnetic memory is disclosed. The method and system include providing a plurality of magnetic storage cells in an array, a plurality of bit lines, and at least one bias structure. Each of the plurality of magnetic storage cells includes at least one magnetic element having an easy axis and being programmable by at least one write current driven through the magnetic element. The plurality of bit lines corresponds to the plurality of magnetic storage cells. The at least one bias structure is magnetically coupled with the at least one magnetic element in each of the plurality of magnetic storage cells. The at least one bias structure provides a bias field in a direction greater than zero degrees and less than one hundred eighty degrees from the easy axis.
    Type: Grant
    Filed: March 27, 2007
    Date of Patent: June 15, 2010
    Assignee: Grandis, Inc.
    Inventors: Zhitao Diao, Lien-Chang Wang, Yiming Huai
  • Publication number: 20100072524
    Abstract: Magnetic multilayer structures, such as magnetic or magnetoresistive tunnel junctions (MTJs) and spin valves, having a magnetic biasing layer formed next to and magnetically coupled to the free ferromagnetic layer to achieve a desired stability against fluctuations caused by, e.g., thermal fluctuations and astray fields. Stable MTJ cells with low aspect ratios can be fabricated using CMOS processing for, e.g., high-density MRAM memory devices and other devices, using the magnetic biasing layer. Such multilayer structures can be programmed using spin transfer induced switching by driving a write current perpendicular to the layers to switch the magnetization of the free ferromagnetic layer.
    Type: Application
    Filed: April 16, 2009
    Publication date: March 25, 2010
    Inventors: Yiming Huai, Zhitao Diao, Eugene Youjun Chen
  • Patent number: 7663848
    Abstract: A method and system for providing a magnetic memory are described. The method and system include providing a plurality of magnetic storage cells. Each of the magnetic storage cells includes at least one magnetic element. The magnetic element(s) includes a pinned layer, a barrier layer that is a crystalline insulator and has a first crystalline orientation, and a free layer. The free layer includes a first ferromagnetic layer, a second ferromagnetic layer, and an intermediate layer between the first and second ferromagnetic layer. The barrier layer resides between the pinned and free layers. The first ferromagnetic layer resides between the barrier layer and the intermediate layer and is ferromagnetically coupled with the second ferromagnetic layer. The intermediate layer is configured such that the first ferromagnetic layer has the first crystalline orientation and the second ferromagnetic layer has a second crystalline orientation different from the first ferromagnetic layer.
    Type: Grant
    Filed: September 20, 2006
    Date of Patent: February 16, 2010
    Assignees: Grandis, Inc., Renesas Technology Corp
    Inventors: Yiming Huai, Zhitao Diao, Eugene Youjun Chen
  • Patent number: 7623369
    Abstract: A method and system for providing a magnetic memory is described. The method and system include providing magnetic memory cells, local and global word lines, bit lines, and source lines. Each magnetic memory cell includes a magnetic element and a selection device connected with the magnetic element. The magnetic element is programed by first and second write currents driven through the magnetic element in first and second directions. The local word lines are connected with the selection device of and have a first resistivity. Each global word line corresponds to a portion of the local word lines and has a resistivity lower than the first resistivity. The bit lines are connected with the magnetic element. The source lines are connected with the selection device. Each source line corresponds to a more than one of the magnetic memory cells and carries the first and second write currents.
    Type: Grant
    Filed: February 13, 2008
    Date of Patent: November 24, 2009
    Assignees: Grandis, Inc., Renesas Technology Corp.
    Inventors: Xiao Luo, Eugene Chen, Lien-Chang Wang, Yiming Huai
  • Publication number: 20090213640
    Abstract: A method and system for providing and using a magnetic memory is described. The method and system include providing a plurality of magnetic storage cells. Each magnetic storage cell includes a magnetic element and a selection device coupled with the magnetic element. The magnetic element is programmed by write currents driven through the magnetic element in a first or second direction. In one aspect, the method and system include providing a voltage supply and a voltage pump coupled with the magnetic storage cells and the voltage supply. The voltage supply provides a supply voltage. The voltage pump provides to the selection device a bias voltage having a magnitude greater than the supply voltage. Another aspect includes providing a silicon on oxide transistor as the selection device. Another aspect includes providing to the body of the transistor a body bias voltage that is a first voltage when the transistor is off and a second voltage when the transistor is on.
    Type: Application
    Filed: March 28, 2009
    Publication date: August 27, 2009
    Applicant: Grandis, Inc.
    Inventors: Eugene Youjun Chen, Yiming Huai
  • Patent number: 7576956
    Abstract: Magnetic or magnetoresistive tunnel junctions (MTJs) having diffusion stop layers to eliminate or reduce diffusion of oxygen, nitrogen or other particles from the barrier layer to the ferromagnetic layers during the film deposition process including the barrier oxidation or nitridation process and the post annealing process. Such MTJs may be used in various applications including magnetic memory (MRAM) devices and magnetic recording heads.
    Type: Grant
    Filed: July 26, 2005
    Date of Patent: August 18, 2009
    Assignee: Grandis Inc.
    Inventor: Yiming Huai
  • Publication number: 20090185410
    Abstract: A magnetic memory cell and a magnetic memory incorporating the cell are described. The magnetic memory cell includes at least one magnetic element and a plurality of unidirectional polarity selection devices. The magnetic element(s) are programmable using write current(s) driven through the magnetic element. The unidirectional polarity selection devices are connected in parallel and such that they have opposing polarities. The magnetic memory may include a plurality of magnetic storage cells, a plurality of bit lines corresponding to the plurality of magnetic storage cells, and a plurality of source lines corresponding to the plurality of magnetic storage cells.
    Type: Application
    Filed: January 22, 2008
    Publication date: July 23, 2009
    Applicant: GRANDIS, INC.
    Inventors: Yiming Huai, Eugene Chen, Frank Albert, Jia-Hwang Chang
  • Patent number: 7531882
    Abstract: A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, nonmagnetic spacer, and free layers. The spacer layer resides between the pinned and free layers. The free layer can be switched using spin transfer when a write current is passed through the magnetic element. The magnetic element may also include a barrier layer, a second pinned layer. Alternatively, second pinned and second spacer layers and a second free layer magnetostatically coupled to the free layer are included. At least one free layer has a high perpendicular anisotropy. The high perpendicular anisotropy has a perpendicular anisotropy energy that is at least twenty and less than one hundred percent of the out-of-plane demagnetization energy.
    Type: Grant
    Filed: September 30, 2005
    Date of Patent: May 12, 2009
    Assignee: Grandis, Inc.
    Inventors: Paul P. Nguyen, Yiming Huai
  • Patent number: 7518835
    Abstract: A method and system for providing a magnetic element are disclosed. The method and system include providing a magnetic biasing structure having a first pinned layer, a second pinned layer, a spacer layer, and a free layer. The first pinned layer has a first magnetization pinned in the first direction. The second pinned layer has a second magnetization in a second direction that is substantially perpendicular or along the first direction. The spacer layer is nonferromagnetic, resides between the second pinned layer and the free layer, and is configured such that the free layer is substantially free of exchange coupling with the second pinned layer. The free layer has a shape anisotropy with a longitudinal direction substantially in the second direction. The magnetic biasing structure provides a bias field for the free layer along the hard or easy axis. In one aspect, the second pinned layer resides between the first pinned layer and the free layer.
    Type: Grant
    Filed: July 1, 2005
    Date of Patent: April 14, 2009
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Dmytro Apalkov
  • Patent number: 7515457
    Abstract: A method and system for providing and using a magnetic memory is described. The method and system include providing a plurality of magnetic storage cells. Each magnetic storage cell includes a magnetic element and a selection device coupled with the magnetic element. The magnetic element is programmed by write currents driven through the magnetic element in a first or second direction. In one aspect, the method and system include providing a voltage supply and a voltage pump coupled with the magnetic storage cells and the voltage supply. The voltage supply provides a supply voltage. The voltage pump provides to the selection device a bias voltage having a magnitude greater than the supply voltage. Another aspect includes providing a silicon on oxide transistor as the selection device. Another aspect includes providing to the body of the transistor a body bias voltage that is a first voltage when the transistor is off and a second voltage when the transistor is on.
    Type: Grant
    Filed: February 24, 2006
    Date of Patent: April 7, 2009
    Assignee: Grandis, Inc.
    Inventors: Eugene Youjun Chen, Yiming Huai
  • Publication number: 20090050991
    Abstract: A magnetic device including a magnetic element is described. The magnetic element includes a fixed layer having a fixed layer magnetization, a spacer layer that is nonmagnetic, and a free layer having a free layer magnetization. The free layer is changeable due to spin transfer when a write current above a threshold is passed through the first free layer.
    Type: Application
    Filed: August 22, 2007
    Publication date: February 26, 2009
    Inventors: Hide Nagai, Zhitao Diao, Yiming Huai
  • Patent number: 7495303
    Abstract: A method and system include providing a single pinned layer, a free layer, and a spacer layer between the pinned and free layers. The spacer layer is nonmagnetic. The magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element. The free layer is a simple free layer. In one aspect, the method and system include providing a spin engineered layer adjacent to the free layer. The spin engineered layer is configured to more strongly scatter majority electrons than minority electrons. In another aspect, at least one of the pinned, free, and spacer layers is a spin engineered layer having an internal spin engineered layer configured to more strongly scatter majority electrons than minority electrons. In this aspect, the magnetic element may include another pinned layer and a barrier layer between the free and pinned layers.
    Type: Grant
    Filed: January 29, 2007
    Date of Patent: February 24, 2009
    Assignee: Grandis, Inc.
    Inventors: Zhitao Diao, Yiming Huai, Thierry Valet, Paul P. Nguyen, Mahendra Pakala
  • Patent number: 7489541
    Abstract: A method and system for providing a magnetic element are disclosed. The method and system include providing a pinned layer, providing a spacer layer, and providing a free layer. The free layer is ferrimagnetic and includes at least one of a conductive ferrite, a garnet, a ferrimagnetic alloy excluding a rare earth, a heavy rare-earth-transition metal alloy, a half-metallic ferrimagnetic, and a bilayer. The bilayer includes a rare earth-transition metal alloy layer and a spin current enhancement layer. The magnetic element is configured to allow the free layer to be switched due to spin transfer when a write current is passed through the magnetic element.
    Type: Grant
    Filed: August 23, 2005
    Date of Patent: February 10, 2009
    Assignee: Grandis, Inc.
    Inventors: Mahendra Pakala, Eugene Youjun Chen, Yiming Huai
  • Publication number: 20080310213
    Abstract: A magnetic memory cell and a magnetic memory incorporating the cell are described. The magnetic memory cell includes at least one magnetic element and at least one non-planar selection device. The magnetic element(s) are programmable using write current(s) driven through the magnetic element. The magnetic memory may include a plurality of magnetic storage cells, a plurality of bit lines corresponding to the plurality of magnetic storage cells, and a plurality of source lines corresponding to the plurality of magnetic storage cells.
    Type: Application
    Filed: June 15, 2007
    Publication date: December 18, 2008
    Applicant: GRANDIS, INC.
    Inventors: Eugene Chen, Yiming Huai, Alexander A.G. Driskill-Smith
  • Publication number: 20080273380
    Abstract: A method and system for providing a magnetic memory is disclosed. The method and system include providing a plurality of magnetic storage cells in an array, a plurality of bit lines, and at least one bias structure. Each of the plurality of magnetic storage cells includes at least one magnetic element having an easy axis and being programmable by at least one write current driven through the magnetic element. The plurality of bit lines corresponds to the plurality of magnetic storage cells. The at least one bias structure is magnetically coupled with the at least one magnetic element in each of the plurality of magnetic storage cells. The at least one bias structure provides a bias field in a direction greater than zero degrees and less than one hundred eighty degrees from the easy axis.
    Type: Application
    Filed: March 27, 2007
    Publication date: November 6, 2008
    Applicant: GRANDIS
    Inventors: Zhitao Diao, Lien-Chang Wang, Yiming Huai
  • Patent number: 7430135
    Abstract: Magnetic multilayer structures, such as magnetic or magnetoresistive tunnel junctions (MTJs) and spin valves, having one or more spin diffusion layers to diffuse the electron spins outside the MTJ or spin valve structure to reduce the spin transfer switching current for switching the free layer.
    Type: Grant
    Filed: December 23, 2005
    Date of Patent: September 30, 2008
    Assignee: Grandis Inc.
    Inventors: Yiming Huai, Zhitao Diao, Alex Panchula, Eugene Youjun Chen, Lien-Chang Wang
  • Publication number: 20080230819
    Abstract: A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes pinned, nonmagnetic spacer, and free layers. The spacer layer resides between the pinned and free layers. The free layer can be switched using spin transfer when a write current is passed through the magnetic element. The free layer includes a first ferromagnetic layer and a second ferromagnetic layer. The second ferromagnetic layer has a very high perpendicular anisotropy and an out-of-plane demagnetization energy. The very high perpendicular anisotropy energy is greater than the out-of-plane demagnetization energy of the second layer.
    Type: Application
    Filed: June 5, 2008
    Publication date: September 25, 2008
    Applicant: GRANDIS, INC.
    Inventors: Paul P. Nguyen, Yiming Huai
  • Publication number: 20080205121
    Abstract: A method and system for providing and using a magnetic memory is described. The method and system include providing a plurality of magnetic storage cells. Each magnetic storage cell includes a magnetic element and a selection device coupled with the magnetic element. The magnetic element is programmed by write currents driven through the magnetic element in a first or second direction. In one aspect, the method and system include providing a voltage supply and a voltage pump coupled with the magnetic storage cells and the voltage supply. The voltage supply provides a supply voltage. The voltage pump provides to the selection device a bias voltage having a magnitude greater than the supply voltage. Another aspect includes providing a silicon on oxide transistor as the selection device. Another aspect includes providing to the body of the transistor a body bias voltage that is a first voltage when the transistor is off and a second voltage when the transistor is on.
    Type: Application
    Filed: February 24, 2006
    Publication date: August 28, 2008
    Inventors: Eugene Youjun Chen, Yiming Huai
  • Publication number: 20080151611
    Abstract: A method and system for providing a magnetic memory is described. The method and system include providing magnetic memory cells, local and global word lines, bit lines, and source lines. Each magnetic memory cell includes a magnetic element and a selection device connected with the magnetic element. The magnetic element is programmed by first and second write currents driven through the magnetic element in first and second directions. The local word lines are connected with the selection device of and have a first resistivity. Each global word line corresponds to a portion of the local word lines and has a resistivity lower than the first resistivity. The bit lines are connected with the magnetic element. The source lines are connected with the selection device. Each source line corresponds to a more than one of the magnetic memory cells and carries the first and second write currents.
    Type: Application
    Filed: February 13, 2008
    Publication date: June 26, 2008
    Applicants: GRANDIS, INC., RENESAS TECHNOLOGY CORP.
    Inventors: Xiao Luo, Eugene Youjun Chen, Lien-Chang Wang, Yiming Huai