Patents Assigned to Grandis, Inc.
  • Patent number: 7126202
    Abstract: A method and system for providing a magnetic element is disclosed. The magnetic element include providing a pinned layer, a spacer layer, and a free layer. The method and system also include providing a heat assisted switching layer and a spin scattering layer between the free layer and the heat assisted switching layer. The spin scattering layer is configured to more strongly scatter majority electrons than minority electrons. The heat assisted switching layer is for improving a thermal stability of the free layer when the free layer is not being switched. Moreover, 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: November 16, 2004
    Date of Patent: October 24, 2006
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Mahendra Pakala
  • Patent number: 7110287
    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, spacer, free, and heat assisted switching layers. The spacer layer resides between the pinned and free layers. The free layer resides between the spacer and heat assisted switching layers. The heat assisted switching layer improves thermal stability of the free layer when the free layer is not being switched, preferably via an exchange coupling. The free layer is switched using spin transfer when a write current is passed through the magnetic element. The write current preferably provides heat that reduces the heat assisted switching layer's stabilization of the free layer. In another aspect, the magnetic element also includes second free, a second spacer, and second pinned layers. The heat assisted switching layer resides between the two free layers, which are magnetostatically coupled.
    Type: Grant
    Filed: February 13, 2004
    Date of Patent: September 19, 2006
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Mahendra Pakala
  • Patent number: 7106624
    Abstract: A method and system for providing a magnetic element capable of being written using spin-transfer effect while generating a high output signal and a magnetic memory using the magnetic element are disclosed. The magnetic element includes a first ferromagnetic pinned layer, a nonmagnetic spacer layer, a ferromagnetic free layer, an insulating barrier layer and a second ferromagnetic pinned layer. The pinned layer has a magnetization pinned in a first direction. The nonmagnetic spacer layer is conductive and is between the first pinned layer and the free layer. The barrier layer resides between the free layer and the second pinned layer and is an insulator having a thickness allowing electron tunneling through the barrier layer. The second pinned layer has a magnetization pinned in a second direction. The magnetic element is configured to allow the magnetization of the free layer to change direction, due to spin transfer when a write current is passed through the magnetic element.
    Type: Grant
    Filed: April 25, 2005
    Date of Patent: September 12, 2006
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Paul P. Nguyen
  • Patent number: 7098494
    Abstract: A magnetic logic cell includes a magnetic element having a pinned layer, a free layer, and a spacer layer. The pinned and free layers have pinned and free layer magnetizations. The spacer layer resides between the pinned and free layers. In one aspect, the magnetic logic cell includes a first configuration line that is electrically connected to the magnetic element and carries a first current and a second configuration line electrically that is insulated from the magnetic element and the first configuration line and carries a second current. The first or second current alone cannot switch the free layer magnetization. The first and second currents together can switch the free layer magnetization. When the first current is driven through the magnetic element and the second current is provided, the combination sets the pinned layer magnetization direction. In one aspect, the pinned layer magnetization is set by heating the AFM layer to approximately at or above the blocking temperature.
    Type: Grant
    Filed: June 16, 2004
    Date of Patent: August 29, 2006
    Assignee: Grandis, Inc.
    Inventors: Mahendra Pakala, Yiming Huai
  • Patent number: 7088609
    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, spacer, free, and spin barrier layers. The spacer layer is nonmagnetic and 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 resides between the spacer layer and the spin barrier layer. The spin barrier layer is configured to reduce an outer surface contribution to a damping constant of the free layer. In one aspect, the spin barrier layer has a high areal resistance and may substantially eliminate spin pumping induced damping. In another aspect, the magnetic element also includes a spin accumulation layer between the spin barrier and free layers. The spin accumulation layer has a high conductivity, preferably being metallic, and may have a long spin diffusion length.
    Type: Grant
    Filed: May 11, 2004
    Date of Patent: August 8, 2006
    Assignee: Grandis, Inc.
    Inventor: Thierry Valet
  • Patent number: 7057921
    Abstract: A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The magnetic element includes first pinned, spacer, free, spin barrier, and second pinned layers. The spacer layer is nonmagnetic and 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 resides between the spacer and spin barrier layers. The spin barrier layer is between the free and second pinned layers. The spin barrier layer is configured to reduce an outer surface contribution to the free layer damping constant. In one aspect, the spin barrier layer has a high areal resistance and may substantially eliminate spin pumping induced damping. In another aspect, the magnetic element also includes a spin accumulation layer between the spin barrier and free layers. The spin accumulation layer has a high conductivity and may have a long spin diffusion length.
    Type: Grant
    Filed: May 11, 2004
    Date of Patent: June 6, 2006
    Assignee: Grandis, Inc.
    Inventor: Thierry Valet
  • Patent number: 7026672
    Abstract: A method and system for providing a magnetic memory is disclosed. The method and system include providing a plurality of magnetic elements and providing at least one stress-assist layer. Each of the plurality of magnetic elements is configured to be written using spin transfer. The at least one stress-assist layer is configured to exert at least one stress on at least one magnetic element of the plurality of magnetic elements during writing. The reduction of spin-transfer switching current is due to stress exerted by the stress-assist layer on the magnetic elements during writing. Stability of the magnetic memory with respect to thermal fluctuations is not compromised because the energy barrier between the two magnetization states is unchanged once the switching current is turned off.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: April 11, 2006
    Assignee: Grandis, Inc.
    Inventors: Mahendra Pakala, Yiming Huai
  • Patent number: 7009877
    Abstract: A magnetic memory device for reading and writing a data state comprises at least three terminals including first, second, and third terminals. The magnetic memory device also includes a spin transfer (ST) driven element, disposed between the first terminal and the second terminal, and a readout element, disposed between the second terminal and the third terminal. The ST driven element includes a first free layer, and a readout element includes a second free layer. A magnetization direction of the second free layer in the readout element indicates a data state. A magnetization reversal of the first free layer within the ST driven element magnetostatically causes a magnetization reversal of the second free layer in the readout element, thereby recording the data state.
    Type: Grant
    Filed: November 14, 2003
    Date of Patent: March 7, 2006
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Paul P. Nguyen, Frank Albert
  • Patent number: 6992359
    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: February 26, 2004
    Date of Patent: January 31, 2006
    Assignee: Grandis, Inc.
    Inventors: Paul P. Nguyen, Yiming Huai
  • Patent number: 6985385
    Abstract: A method and system for providing a magnetic element capable of storing multiple bits is disclosed. The method and system include providing first pinned layer, a first nonmagnetic layer, a first free layer, a connecting layer, a second pinned layer, a second nonmagetic layer and a second free layer. The first pinned layer is ferromagnetic and has a first pinned layer magnetization pinned in a first direction. The first nonmagnetic layer resides between the first pinned layer and the first free layer. The first free layer being ferromagnetic and has a first free layer magnetization. The second pinned layer is ferromagnetic and has a second pinned layer magnetization pinned in a second direction. The connecting layer resides between the second pinned layer and the first free layer. The second nonmagnetic layer resides between the second pinned layer and the second free layer. The second free layer being ferromagnetic and having a second free layer magnetization.
    Type: Grant
    Filed: August 26, 2003
    Date of Patent: January 10, 2006
    Assignee: Grandis, Inc.
    Inventors: Paul P. Nguyen, Yiming Huai
  • Patent number: 6967863
    Abstract: A method and system for providing a magnetic element that can be used in a magnetic memory is disclosed. The method and system include providing a first pinned layer, a barrier layer, a free layer, a conductive nonmagnetic spacer layer, and a second pinned layer. Each pinned layer has a pinned layer easy axis. At least a portion of the pinned layer easy axis is in a perpendicular direction. The barrier layer resides between the first pinned layer and the free layer. The spacer layer is between the free layer and the second pinned layer. The free layer has a free layer easy axis, at least a portion of which is in the perpendicular direction. The magnetic element is also configured to allow the free layer to be switched due to spin transfer effect when a write current is passed through the magnetic element. Because of the perpendicular magnetization(s), the writing current for spin transfer may be significantly reduced.
    Type: Grant
    Filed: February 25, 2004
    Date of Patent: November 22, 2005
    Assignee: Grandis, Inc.
    Inventor: Yiming Huai
  • Patent number: 6958927
    Abstract: A magnetic element that can be used in a memory array having high density includes a pinned layer, a half-metallic material layer, a spacer (or a barrier) layer and a free layer. The half-metallic material layer is formed on the pinned layer and preferably has a thickness that is less than about 100 ?. The half-metallic material layer can be formed to be a continuous layer or a discontinuous on the pinned layer. The spacer (or barrier) layer is formed on the half-metallic material layer, such that the spacer (or barrier) layer is nonmagnetic and conductive (or insulating). The free layer is formed on the spacer (or barrier) layer and has a second magnetization that changes direction based on the spin-transfer effect when a write current passes through the magnetic element.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: October 25, 2005
    Assignee: Grandis Inc.
    Inventors: Paul P. Nguyen, Yiming Huai
  • Patent number: 6933155
    Abstract: A method for providing a magnetic element is disclosed. The method includes providing at least one magnetic element layer and providing a hard mask structure for masking a portion of the at least one magnetic element layer. The hard mask structure is made from hard mask material(s) that are etchable for defining the hard mask structure. The hard mask structure also acts as a mask during definition of a width of the magnetic element. The method also includes defining the width of the magnetic element by removing a portion of the at least one magnetic element layer using the hard mask structure as a mask. The hard mask structure preferably acts as a polishing stop for a planarization step, such as a chemical mechanical polish, polishing resistant structures might be provided to improve planarization of a magnetic memory incorporating the magnetic element.
    Type: Grant
    Filed: May 21, 2003
    Date of Patent: August 23, 2005
    Assignee: Grandis, Inc.
    Inventors: Frank Albert, Yiming Huai, Paul P. Nguyen
  • Patent number: 6920063
    Abstract: A method and system for providing a magnetic element capable of being written using spin-transfer effect while generating a high output signal and a magnetic memory using the magnetic element are disclosed. The magnetic element includes a first ferromagnetic pinned layer, a nonmagnetic spacer layer, a ferromagnetic free layer, an insulating barrier layer and a second ferromagnetic pinned layer. The pinned layer has a magnetization pinned in a first direction. The nonmagnetic spacer layer is conductive and is between the first pinned layer and the free layer. The barrier layer resides between the free layer and the second pinned layer and is an insulator having a thickness allowing electron tunneling through the barrier layer. The second pinned layer has a magnetization pinned in a second direction. The magnetic element is configured to allow the magnetization of the free layer to change direction due to spin transfer when a write current is passed through the magnetic element.
    Type: Grant
    Filed: December 18, 2003
    Date of Patent: July 19, 2005
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Paul P. Nguyen
  • Patent number: 6888742
    Abstract: A method and system for providing a magnetic element capable of being written in a reduced time using the spin-transfer effect while generating a high output signal and a magnetic memory using the magnetic element are disclosed. The magnetic element includes a ferromagnetic pinned layer, a nonmagnetic intermediate layer, and a ferromagnetic free layer. The pinned layer has a magnetization pinned in a first direction. The nonmagnetic intermediate layer resides between the pinned layer and the free layer. The free layer has a magnetization with an easy axis in a second direction. The first direction is in the same plane as the second direction and is oriented at an angle with respect to the second direction. This angle is different from zero and ? radians. The magnetic element is also configured to allow the magnetization of the free layer to change direction due to spin transfer when a write current is passed through the magnetic element.
    Type: Grant
    Filed: August 28, 2002
    Date of Patent: May 3, 2005
    Assignee: Grandis, Inc.
    Inventors: Paul P. Nguyen, Yiming Huai
  • Patent number: 6847547
    Abstract: A method and system for providing a magnetic element and a corresponding memory are disclosed. In one aspect, the method and system include providing a dual spin tunnel/valve structure and at least one spin valve. The dual spin tunnel/valve structure includes a nonmagnetic spacer layer between a pinned layer and a free layer, another pinned layer and a barrier layer between the free layer and the other pinned layer. The free layers of the dual spin tunnel/valve structure and the spin valve are magnetostatically coupled. In one embodiment a separation layer resides between the dual spin tunnel/valve structure and the spin valve. In another aspect, the method and system include providing two dual spin valves, a spin tunneling junction there between and, in one embodiment, the separation layer. In both aspects, the magnetic element is configured to write to the free layers using spin transfer when a write current is passed through the magnetic element.
    Type: Grant
    Filed: February 28, 2003
    Date of Patent: January 25, 2005
    Assignee: Grandis, Inc.
    Inventors: Frank Albert, Yiming Huai, Paul P. Nguyen
  • Patent number: 6838740
    Abstract: A method and system for providing a magnetic element capable of being written using spin-transfer effect while being thermally stable and a magnetic memory using the magnetic element are disclosed. The magnetic element includes a first, second and third pinned layers, first and second nonmagnetic layers, a free layer and a nonmagnetic spacer layers. The first, second and third pinned layers are ferromagnetic and have first, second and third magnetizations pinned in first, second and third directions. The first and second nonmagnetic layers include first and second diffusion barriers, respectively. The first and second nonmagnetic layers are between the first and second pinned layers and the second and third pinned layers, respectively. The first and second pinned layers and the second and third pinned layers are antiferromagnetically coupled. The nonmagnetic spacer layer is conductive and resides between the free layer and the third pinned layer.
    Type: Grant
    Filed: September 27, 2002
    Date of Patent: January 4, 2005
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Paul P. Nguyen
  • Patent number: 6829161
    Abstract: A method and system for providing a magnetic element capable of being written using the spin-transfer effect and a magnetic memory using the magnetic element are disclosed. The magnetic element includes a spin tunneling junction, a separation layer and a spin valve. In an alternate embodiment, the spin tunneling junction and/or spin valve may be dual. The separation layer is between a first free layer of the spin tunneling junction and a second free layer of the spin valve. The separation layer is configured so that the two free layers are magnetostatically coupled, preferably with their magnetizations antiparallel. In an alternate embodiment, having a dual spin valve and a dual spin tunneling junction, the separation layer may be omitted, and the appropriate distance provided using an antiferromagnetic layer. Another embodiment includes shaping the element such that the spin valve has a smaller lateral dimension than the spin tunneling junction.
    Type: Grant
    Filed: January 10, 2003
    Date of Patent: December 7, 2004
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Frank Albert, Paul P. Nguyen
  • Publication number: 20040130936
    Abstract: A magnetic element for a high-density memory array includes a resettable layer and a storage layer. The resettable layer has a magnetization that is set in a selected direction by at least one externally generated magnetic field. The storage layer has at least one magnetic easy axis and a magnetization that changes direction based on the spin-transfer effect when a write current passes through the magnetic element. An alternative embodiment of the magnetic element includes an additional multilayer structure formed from a tunneling barrier layer, a pinned magnetic layer and an antiferromagnetic layer that pins the magnetization of the pinned layer in a predetermined direction. Another alternative embodiment of the magnetic element includes an additional multilayer structure that is formed from a tunneling barrier layer and a second resettable layer having a magnetic moment that is different from the magnetic moment of the resettable layer of the basic embodiment.
    Type: Application
    Filed: January 7, 2003
    Publication date: July 8, 2004
    Applicant: Grandis Inc.
    Inventors: Paul P. Nguyen, Yiming Huai
  • Patent number: 6714444
    Abstract: A method and system for providing a magnetic element capable of being written using spin-transfer effect while generating a high output signal and a magnetic memory using the magnetic element are disclosed. The magnetic element includes a first ferromagnetic pinned layer, a nonmagnetic spacer layer, a ferromagnetic free layer, an insulating barrier layer and a second ferromagnetic pinned layer. The pinned layer has a magnetization pinned in a first direction. The nonmagnetic spacer layer is conductive and is between the first pinned layer and the free layer. The barrier layer resides between the free layer and the second pinned layer and is an insulator having a thickness allowing electron tunneling through the barrier layer. The second pinned layer has a magnetization pinned in a second direction. The magnetic element is configured to allow the magnetization of the free layer to change direction due to spin transfer when a write current is passed through the magnetic element.
    Type: Grant
    Filed: August 6, 2002
    Date of Patent: March 30, 2004
    Assignee: Grandis, Inc.
    Inventors: Yiming Huai, Paul P. Nguyen