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.
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.
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.
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
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.
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).
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.
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.
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).
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
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.
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.
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.
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.
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.
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
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.
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
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.
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.