Patents Assigned to Grandis, Inc.
-
Patent number: 7379327Abstract: A method and system for providing a magnetic memory. The magnetic memory includes magnetic storage cells in an array, bit lines, and source lines. Each magnetic storage cell includes at least one magnetic element. The magnetic element(s) are programmable by write currents driven through the magnetic element(s). Each magnetic element has free and pinned layer(s) and a dominant spacer.Type: GrantFiled: June 26, 2006Date of Patent: May 27, 2008Assignees: Grandis, Inc., Renesas Technology Corp.Inventors: Eugene Youjun Chen, Yiming Huai, Alex Fischer Panchula, Lien-Chang Wang, Xiao Luo
-
Magnetic elements with spin engineered insertion layers and MRAM devices using the magnetic elements
Patent number: 7369427Abstract: A method and system include providing a 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. 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: GrantFiled: September 9, 2004Date of Patent: May 6, 2008Assignee: Grandis, Inc.Inventors: Zhitao Diao, Yiming Huai, Thierry Valet, Paul P. Nguyen, Mahendra Pakala -
Patent number: 7345912Abstract: 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: GrantFiled: June 1, 2006Date of Patent: March 18, 2008Assignees: Grandis, Inc., Renesas Technology Corp.Inventors: Xiao Luo, Eugene Youjun Chen, Lien-Chang Wang, Yiming Huai
-
Patent number: 7289356Abstract: A method and system for providing a magnetic memory is described. The method and system include providing a plurality of magnetic storage cells, a plurality of word lines, and a plurality of bit lines. Each of the plurality of magnetic storage cells includes a plurality of magnetic elements and at least one selection transistor. Each of the plurality of magnetic elements is capable of being programmed using spin transfer induced switching by a write current driven through the magnetic element. Each of the plurality of magnetic elements has a first end and a second end. The at least one selection transistor is coupled to the first end of each of the plurality of magnetic elements. The plurality of word lines is coupled with the plurality of selection transistors and selectively enables a portion of the plurality of selection transistors.Type: GrantFiled: June 8, 2005Date of Patent: October 30, 2007Assignee: Grandis, Inc.Inventors: Zhitao Diao, Yiming Huai, Mahendra Pakala, Zhenghong Qian
-
Patent number: 7286395Abstract: A method and system for providing a magnetic memory is described. The magnetic memory includes a plurality of magnetic storage cell and at least one bit line and a plurality of source lines corresponding to the plurality of magnetic storage cells. Each magnetic storage cell includes a magnetic element that is programmed to a high resistance state by a first write current driven through the magnetic element in a first direction and to a low resistance state by a second write current driven through the magnetic element in a second direction. The bit line(s) and the source lines are configured to drive the first write current through the magnetic element in the first direction, to drive the second write current through the magnetic element in the second direction, and to drive at least one read current through the magnetic element in a third direction that does not destabilize the low resistance state.Type: GrantFiled: October 27, 2005Date of Patent: October 23, 2007Assignee: Grandis, Inc.Inventors: Eugene Youjun Chen, Yiming Huai
-
Patent number: 7282755Abstract: 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: GrantFiled: November 14, 2003Date of Patent: October 16, 2007Assignee: Grandis, Inc.Inventors: Mahendra Pakala, Yiming Huai
-
Patent number: 7272034Abstract: A method and system for providing a magnetic memory is described. The method and system include providing a plurality of magnetic storage cells. Each of the plurality of magnetic storage cells includes at least one magnetic element and a plurality of selection transistors. The at least one magnetic element is capable of being programmed using spin transfer induced switching by a write current driven through the at least one magnetic element. The at least one selection transistor is configured to allow the magnetic element to be alternately selected for writing and reading. Architectures for reading and writing to the magnetic storage cells are also described.Type: GrantFiled: August 31, 2005Date of Patent: September 18, 2007Assignee: Grandis, Inc.Inventors: Eugene Youjun Chen, Yiming Huai
-
Patent number: 7272035Abstract: A method and system for providing a magnetic memory is described. The method and system include providing a plurality of magnetic storage cells. Each of the plurality of magnetic storage cells includes a magnetic element and a selection transistor. The magnetic element may be programmed using spin transfer induced switching by a write current driven through the magnetic element. The selection transistor includes a source and a drain. The plurality of magnetic storage cells are grouped in pairs. The source of the selection transistor for one magnetic storage cell of a pair shares the source with the selection transistor for another magnetic storage cell of the pair.Type: GrantFiled: August 31, 2005Date of Patent: September 18, 2007Assignee: Grandis, Inc.Inventors: Eugene Youjun Chen, Yiming Huai
-
Patent number: 7245462Abstract: A method and system for providing a magnetic element is disclosed. The method and system include providing a ferromagnetic pinned layer, providing a free layer, and providing a spacer layer between the pinned layer and the free layer. The pinned layer and free layer are ferromagnetic and have a pinned layer magnetization and a free layer magnetization, respectively. The spacer layer is nonmagnetic. In one aspect, the free layer is configured to have an increased magnetic damping constant. In another aspect, the method and system also include providing a second pinned layer and a second spacer layer between the free layer and the second pinned layer. In this aspect, the first pinned layer and/or the second pinned layer are configured such that a forward torque and a reflected torque due to a current driven through the magnetic element in a current-perpendicular-to-plane configuration are substantially equal and opposite.Type: GrantFiled: May 5, 2004Date of Patent: July 17, 2007Assignee: Grandis, Inc.Inventors: Yiming Huai, Paul P. Nguyen
-
Patent number: 7241631Abstract: A method and system for providing a magnetic element are disclosed. The method and system include providing first and second pinned layers, a free layer, and first and second barrier layers between the first and second pinned layers, respectively, and the free layer. The first barrier layer is preferably crystalline MgO, which is insulating, and configured to allow tunneling through the first barrier layer. Furthermore, the first barrier layer has an interface with another layer, such as the free layer or the first pinned layer. The interface has a structure that provides a high spin polarization of at least fifty percent and preferably over eighty percent. The second barrier layer is insulating and configured to allow tunneling through the second barrier 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: GrantFiled: December 29, 2004Date of Patent: July 10, 2007Assignee: Grandis, Inc.Inventors: Yiming Huai, Mahendra Pakala
-
Patent number: 7242045Abstract: 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. In one aspect, the free layer(s) include ferromagnetic material(s) diluted with nonmagnetic material(s) and/or ferrimagnetically doped to provide low saturation magnetization(s).Type: GrantFiled: February 19, 2004Date of Patent: July 10, 2007Assignee: Grandis, Inc.Inventors: Paul P. Nguyen, Yiming Huai, Zhitao Diao, Frank Albert
-
Patent number: 7242048Abstract: A method and system for providing a magnetic element is disclosed. The method and system include providing a pinned layer, a magnetic current confined layer, and a free layer. The pinned layer is ferromagnetic and has a first pinned layer magnetization. The magnetic current confined layer has at least one channel in an insulating matrix and resides between the pinned layer and the free layer. The channel(s) are ferromagnetic, conductive, and extend through the insulating matrix between the free layer and the pinned layer. The size(s) of the channel(s) are sufficiently small that charge carriers can give rise to ballistic magnetoresistance in the magnetic current confined layer. The free layer is ferromagnetic and has a free layer magnetization. Preferably, the method and system also include providing a second pinned layer and a nonmagnetic spacer layer between the second pinned layer and the free layer.Type: GrantFiled: April 28, 2006Date of Patent: July 10, 2007Assignee: Grandis, Inc.Inventor: Yiming Huai
-
Patent number: 7233039Abstract: A method and system for providing a magnetic element is disclosed. The method and system include providing a free layer, a spacer layer, and a pinned layer. The free layer is ferromagnetic and has a free layer magnetization. The spacer layer is nonmagnetic and resides between the pinned and free layers. The pinned layer includes first and second ferromagnetic layers having first and second magnetizations, a nonmagnetic spacer layer, and a spin depolarization layer. Residing between the first and second ferromagnetic layers, the nonmagnetic spacer layer is conductive and promotes antiparallel orientations between the first and second magnetizations. The spin depolarization layer is configured to depolarize at least a portion of a plurality of electrons passing through it. The magnetic element is also configured to allow the free layer magnetization to change direction due to spin transfer when a write current is passed through the magnetic element.Type: GrantFiled: April 21, 2004Date of Patent: June 19, 2007Assignee: Grandis, Inc.Inventors: Yiming Huai, Paul P. Nguyen
-
Patent number: 7230845Abstract: A method and system for providing a magnetic memory device are disclosed. The method and system include providing a magnetic element that includes a data storage layer having at least one easy axis in at least a first direction. The method and system also include providing a hard bias structure surrounding a portion of the magnetic element. The hard bias structure is also configured to provide at least one hard bias field essentially parallel to the at least the first direction or essentially perpendicular to the at least the first direction.Type: GrantFiled: July 29, 2005Date of Patent: June 12, 2007Assignee: Grandis, Inc.Inventors: Lien-Chang Wang, Yiming Huai
-
Patent number: 7227773Abstract: 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: GrantFiled: October 21, 2005Date of Patent: June 5, 2007Assignee: Grandis, Inc.Inventors: Paul P. Nguyen, Yiming Huai
-
Patent number: 7224601Abstract: Devices and techniques for applying a resonant action by an applied oscillating magnetic field to a magnetic tunnel junction (MTJ) and an action of an applied DC current across the MTJ to effectuate a switching of the MTJ when writing data to the MTJ.Type: GrantFiled: November 9, 2005Date of Patent: May 29, 2007Assignee: Grandis Inc.Inventor: Alex Panchula
-
Patent number: 7190611Abstract: 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: GrantFiled: January 7, 2003Date of Patent: March 13, 2007Assignee: Grandis, Inc.Inventors: Paul P. Nguyen, Yiming Huai
-
Patent number: 7190612Abstract: A method and system for providing a magnetic memory is described. The method and system include providing a plurality of magnetic storage cells, providing a bit line, providing a plurality of word lines, providing bit line read/write logic, and providing a plurality of switches for the bit line. Each of the magnetic storage cells includes a magnetic storage element capable of being programmed by a write current driven through the magnetic storage element. The bit line corresponds to the magnetic storage cells. Each of the word lines corresponds to a magnetic storage cell of the magnetic storage cells and allows current to flow through the magnetic storage cell. The bit line read/write logic corresponds to the bit line. The switches are for the bit line and controlled by the bit line read/write logic to selectively provide a read current or the write current to the magnetic storage elements.Type: GrantFiled: March 31, 2005Date of Patent: March 13, 2007Assignee: Grandis, Inc.Inventors: Zhenghong Qian, Yiming Huai
-
Patent number: 7187577Abstract: A method and system for providing a magnetic memory is included. The method and system include providing at least one magnetic storage cell and at least one dummy resistor coupled with the at least one magnetic storage cell at least for a write operation of the at least one magnetic storage cell. Each of the at least one magnetic storage cell includes a magnetic element and a selection device coupled with the magnetic element. The magnetic element being programmed by a first write current driven through the magnetic element in a first direction and a second write current driven through the magnetic element in a second direction. The selection device is configured to be coupled between the magnetic element and the at least one dummy resistor.Type: GrantFiled: November 23, 2005Date of Patent: March 6, 2007Assignee: Grandis, Inc.Inventors: Lien-Chang Wang, Zhitao Diao, Yunfei Ding
-
Patent number: 7161829Abstract: A method and system for providing and magnetic element is disclosed. In one aspect, the magnetic element includes at least a pinned layer, a free layer, and a current confined layer residing between the pinned layer and the free layer. The pinned layer is ferromagnetic and has a first magnetization. The current confined layer has at least one channel in an insulating matrix. The channel(s) are conductive and extend through the current confined layer. The free layer is ferromagnetic and has a second magnetization. The pinned layer, the free layer, and the current confined layer are configured to allow the magnetization of the free layer to be switched using spin transfer. The magnetic element may also include other layers, including layers for spin valve(s), spin tunneling junction(s), dual spin valve(s), dual spin tunneling junction(s), and dual spin valve/tunnel structure(s).Type: GrantFiled: September 19, 2003Date of Patent: January 9, 2007Assignee: Grandis, Inc.Inventors: Yiming Huai, Paul P. Nguyen, Frank Albert