Patents Assigned to Grandis, Inc.
  • 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: 7532505
    Abstract: A method and system for providing and utilizing a magnetic memory are described. The magnetic memory includes a plurality of magnetic storage cells. Each magnetic storage cell includes magnetic element(s) programmable due to spin transfer when a write current is passed through the magnetic element(s) and selection device(s). The method and system include driving a first current in proximity to but not through the magnetic element(s) of a portion of the magnetic storage cells. The first current generates a magnetic field. The method and system also include driving a second current through the magnetic element(s) of the portion of the magnetic storage cells. The first and second currents are preferably both driven through bit line(s) coupled with the magnetic element(s). The first and second currents are turned on at a start time. The second current and the magnetic field are sufficient to program the magnetic element(s).
    Type: Grant
    Filed: July 17, 2006
    Date of Patent: May 12, 2009
    Assignees: Grandis, Inc., Renesas Technology Corp.
    Inventor: Yunfei Ding
  • 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
  • Patent number: 7502249
    Abstract: A method and system for providing and utilizing a magnetic memory are described. The magnetic memory includes a plurality of magnetic storage cells. Each magnetic storage cell includes magnetic element(s) programmable due to spin transfer when a write current is passed through the magnetic element(s) and selection device(s). The method and system include driving a first current in proximity to but not through the magnetic element(s) of a portion of the magnetic storage cells. The first current generates a magnetic field. The method and system also include driving a second current through the magnetic element(s) of the portion of the magnetic storage cells. The first and second currents are preferably both driven through bit line(s) coupled with the magnetic element(s). The first and second currents are turned on at a start time. The second current and the magnetic field are sufficient to program the magnetic element(s).
    Type: Grant
    Filed: April 17, 2007
    Date of Patent: March 10, 2009
    Assignees: Grandis, Inc., Renesas Technology Corp.
    Inventor: Yunfei Ding
  • 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
  • Publication number: 20090040855
    Abstract: A method and system for providing a magnetic memory are described. The method and system include a plurality of magnetic storage cells, a plurality of bit lines, at least one reference line, and at least one sense amplifier. Each magnetic storage cell includes magnetic element(s) and selection device(s). The magnetic element(s) are programmable using write current(s) driven through the magnetic element. The bit and source lines correspond to the magnetic storage cells. The sense amplifier(s) are coupled with the bit lines and reference line(s), and include logic and a plurality of stages. The stages include first and second stages. The first stage converts at least current signal to at least one differential voltage signal. The second stage amplifies the at least one differential voltage signal. The logic selectively disablies at least one of the first and second stages in the absence of a read operation and enabling the first and second stages during the read operation.
    Type: Application
    Filed: August 7, 2007
    Publication date: February 12, 2009
    Applicants: GRANDIS, INC., RENESAS TECHNOLOGY CORP.
    Inventors: Xiao Luo, David Chang-Cheng Yu
  • 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
  • Patent number: 7486551
    Abstract: A method and system for providing a magnetic element is described. The magnetic element includes a pinned layer, a spacer layer, and a free layer. The spacer layer is nonferromagnetic and resides between the pinned layer and the free layer. The free layer includes a first magnetic layer and at least one of a second magnetic layer and an intermediate layer. The intermediate layer would reside between the first and second magnetic layers. The free layer also includes at least one domain wall therein during switching. In addition, the magnetic element is configured to allow the free layer to be switched at least in part due to spin transfer when a write current is passed through the magnetic element.
    Type: Grant
    Filed: April 3, 2007
    Date of Patent: February 3, 2009
    Assignee: Grandis, Inc.
    Inventors: Zhanjie Li, Shengyuan Wang
  • Patent number: 7486552
    Abstract: A method and system for providing a magnetic element is described. The magnetic element includes a first pinned layer, a first spacer layer, a free layer, a second spacer layer, and a second pinned layer. The first and second pinned layers have first and magnetizations oriented in first and second directions, respectively. The first and second spacer layers are nonferromagnetic. The first and second spacer layers are between the free layer and the first and second pinned layers, respectively.
    Type: Grant
    Filed: June 15, 2007
    Date of Patent: February 3, 2009
    Assignee: Grandis, Inc.
    Inventors: Dmytro Apalkov, Zhanjie Li
  • Publication number: 20080310219
    Abstract: A method and system for providing a magnetic element and memory utilizing the magnetic element are described. The magnetic element includes a reference layer, a nonferromagnetic spacer layer, and a free layer. The reference layer has a resettable magnetization that is set in a selected direction by a magnetic field generated externally to the reference layer. The reference layer is also magnetically thermally unstable at an operating temperature range and has KuV/kBT is less than fifty five. The spacer layer resides between the reference layer and the free layer. In addition, the magnetic element is configured to allow the free layer to be switched to each of a plurality of states when a write current is passed through the magnetic element.
    Type: Application
    Filed: June 11, 2008
    Publication date: December 18, 2008
    Applicants: Grandis, Inc., Renesas Technology Corp.
    Inventors: Eugene Chen, Dmytro Apalkov
  • 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: 20080291721
    Abstract: A method and system for providing a magnetic element is described. The magnetic element includes a first pinned layer, a first spacer layer, a free layer, a second spacer layer, and a second pinned layer. The first and second pinned layers have first and magnetizations oriented in first and second directions, respectively. The first and second spacer layers are nonferromagnetic. The first and second spacer layers are between the free layer and the first and second pinned layers, respectively.
    Type: Application
    Filed: June 15, 2007
    Publication date: November 27, 2008
    Applicant: GRANDIS, INC.
    Inventors: Dmytro Apalkov, Zhanjie Li
  • 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: 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