Spin Dependent Tunnel (sdt) Junction (e.g., Tunneling Magnetoresistance (tmr), Etc.) Patents (Class 977/935)
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Patent number: 8717812Abstract: The present disclosure concerns a magnetic memory element suitable for a thermally-assisted switching write operation, comprising a current line in electrical communication with one end of a magnetic tunnel junction, the magnetic tunnel junction comprising: a first ferromagnetic layer having a fixed magnetization; a second ferromagnetic layer having a magnetization that can be freely aligned at a predetermined high temperature threshold; and a tunnel barrier provided between the first and second ferromagnetic layer; the current line being adapted to pass a heating current through the magnetic tunnel junction during the write operation; wherein said magnetic tunnel junction further comprises at least one heating element being adapted to generate heat when the heating current is passed through the magnetic tunnel junction; and a thermal barrier in series with said at least one heating element, said thermal barrier being adapted to confine the heat generated by said at least one heating element within the magnetType: GrantFiled: October 26, 2011Date of Patent: May 6, 2014Assignee: Crocus Technology SAInventors: Kenneth Mackay, Ioan Lucian Prejbeanu
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Publication number: 20140110803Abstract: A method and system for providing a magnetic junction usable in a magnetic device are described. The magnetic junction includes a pinned layer, a nonmagnetic spacer layer, and a free layer. The nonmagnetic spacer layer is between the pinned layer and the free layer. The free layer has a magnetic anisotropy, at least a portion of which is a biaxial anisotropy. The magnetic junction is configured such that the free layer is switchable between a plurality of stable magnetic states when a write current is passed through the magnetic junction.Type: ApplicationFiled: January 11, 2013Publication date: April 24, 2014Applicants: The Board of Trustees of the University of Alabama for and on Behalf of the University of Alabama, Samsung Electronics Co., Ltd.Inventors: Dmytro Apalkov, William H. Butler
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Patent number: 8693239Abstract: There is disclosed a memory element including a memory layer that has a magnetization perpendicular to a film face and a magnetization direction thereof varies corresponding to information; a magnetization-fixed layer that has a magnetization that is perpendicular to the film face; and an insulating layer that is provided between the memory layer and the magnetization-fixed layer, wherein the memory layer has a lamination structure of a Co—Fe—B layer and an element belonging to any one of 1A group, 2A group, 3A group, 5A group, or 6A group, an electron that is spin-polarized is injected in a lamination direction of a layered structure, and thereby the magnetization direction of the memory layer varies and a recording of information is performed with respect to the memory layer, a magnitude of an effective diamagnetic field which the memory layer receives is smaller than a saturated magnetization amount of the memory layer.Type: GrantFiled: September 7, 2011Date of Patent: April 8, 2014Assignee: Sony CorporationInventors: Masanori Hosomi, Kazuhiro Bessho, Hiroyuki Ohmori, Yutaka Higo, Kazutaka Yamane, Hiroyuki Uchida
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Patent number: 8681542Abstract: A magnetic memory device includes: a free layer for storing information; and a reference layer disposed on a first surface of the free layer. The reference layer includes at least two magnetic domains and a magnetic domain wall between the at least two magnetic domains. The reference layer extends past both ends of the free layer. The magnetic memory device further includes a switching element connected to a second surface of the free layer. Another magnetic memory device includes: a first reference layer having a first magnetic domain wall; a second reference layer having a second magnetic domain wall; and a memory structure between the first and second reference layers. The memory structure includes: a first free layer adjacent to the first reference layer; a second free layer adjacent to the second reference layer; and a switching element between the first and second free layers.Type: GrantFiled: July 11, 2013Date of Patent: March 25, 2014Assignee: Samsung Electronics Co., Ltd.Inventor: In-jun Hwang
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Patent number: 8675400Abstract: According to one embodiment, a magnetic memory includes a magnetoresistive element includes a first reference layer, a first nonmagnetic layer, a recording layer, a second nonmagnetic layer, and a second reference layer which are sequentially stacked, the recording layer being connected to a terminal to which a high-level voltage is applied, a magnetization direction of the recording layer being variable, magnetization directions of the first and second reference layers being invariable and antiparallel, a first selection transistor connected between a first bit line and the first reference layer, and constituted of an N-channel MOSFET, a second selection transistor connected between a second bit line and the second reference layer, and constituted of an N-channel MOSFET, and a word line connected to gates of the first and second selection transistors.Type: GrantFiled: September 16, 2011Date of Patent: March 18, 2014Assignee: Kabushiki Kaisha ToshibaInventor: Akira Katayama
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Patent number: 8665638Abstract: Systems and method for reading/sensing data stored in magnetoresistive random access memory (MRAM) cells using magnetically annealed reference cells. A MRAM includes a reference circuit comprising at least one magnetic storage cell, wherein each magnetic storage cell in the MRAM is programmed to the same state. The reference circuit includes a load element coupled to the magnetic storage cell, wherein the load element is configured to establish a reference voltage during a read operation.Type: GrantFiled: July 11, 2011Date of Patent: March 4, 2014Assignee: QUALCOMM IncorporatedInventors: Hari M. Rao, Xiaochun Zhu
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Patent number: 8654577Abstract: An array of rows and columns of SMT MRAM cells has each of the columns associated with one of its adjacent columns. Each of the SMT MRAM cells of the column is connected to a true data bit line and each of the SMT MRAM cells of the associated pair of columns is connected to a shared complement data bit line. A shunting switch device is connected between each of the true data bit lines and the shared complement data bit line for selectively connecting one of the true data bit lines to the shared complement data bit line to effectively reduce the resistance of the complement data bit line and to eliminate program disturb effects in adjacent non-selected columns of the SMT MRAM cells.Type: GrantFiled: May 4, 2013Date of Patent: February 18, 2014Assignees: MagIC Technologies, Inc., International Business Machines CorporationInventors: Hsu-Kai Yang, Yutaka Nakamura, John Debrosse
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Patent number: 8634234Abstract: A magnetic random access memory (MRAM) cell includes an embedded MRAM and an access transistor. The embedded MRAM is formed on a number of metal-interposed-in-interlayer dielectric (ILD) layers, which each include metal dispersed there through and are formed on top of the access transistor. A magneto tunnel junction (MTJ) is formed on top of a metal formed in the ILD layers that is in close proximity to a bit line. An MTJ mask is used to pattern the MTJ and is etched to expose the MTJ. Ultimately, metal is formed on top of the bit line and extended to contact the MTJ.Type: GrantFiled: June 28, 2013Date of Patent: January 21, 2014Assignee: Avalanche Technology, Inc.Inventors: Parviz Keshtbod, Ebrahim Abedifard
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Patent number: 8634233Abstract: Systems and methods that enable direct communications between magnetic tunnel junctions are provided. In one embodiment, a device includes multiple input magnetic tunnel junctions and an output magnetic tunnel junction. The multiple input magnetic tunnel junctions are connected in parallel, and the output magnetic tunnel junction is connected in series to the input magnetic tunnel junctions. In another embodiment, a device includes a first magnetic tunnel junction, a second magnetic tunnel junction, and a nano-magnetic channel. Each of the first and the second magnetic tunnel junctions has a free layer, a nonmagnetic layer, and a fixed layer. The nano-magnetic channel connects the free layer of the first magnetic tunnel junction to the free layer of the second magnetic tunnel junction.Type: GrantFiled: May 18, 2012Date of Patent: January 21, 2014Assignee: Regents of the University of MinnesotaInventors: David J. Lilja, Jian-Ping Wang, Andrew P. Lyle, Shruti R. Patil, Jonathan D. Harms, Xiaofeng Yao
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Patent number: 8630112Abstract: The present disclosure concerns a multilevel magnetic element comprising a first tunnel barrier layer between a soft ferromagnetic layer having a magnetization that can be freely aligned and a first hard ferromagnetic layer having a magnetization that is fixed at a first high temperature threshold and freely alignable at a first low temperature threshold. The magnetic element further comprises a second tunnel barrier layer and a second hard ferromagnetic layer having a magnetization that is fixed at a second high temperature threshold and freely alignable at a first low temperature threshold; the soft ferromagnetic layer being comprised between the first and second tunnel barrier layers. The magnetic element disclosed herein allows for writing four distinct levels using only a single current line.Type: GrantFiled: October 26, 2011Date of Patent: January 14, 2014Assignee: Crocus Technology SAInventor: Bertrand Cambou
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Patent number: 8625342Abstract: A storage element includes: a storage layer which retains information by a magnetization state of a magnetic substance; a magnetization pinned layer having magnetization which is used as the basis of the information stored in the storage layer; and an interlayer of a non-magnetic substance provided between the storage layer and the magnetization pinned layer. The storage element is configured to store information by reversing magnetization of the storage layer using spin torque magnetization reversal generated by a current passing in a laminate direction of a layer structure including the storage layer, the interlayer, and the magnetization pinned layer, and when the saturation magnetization of the storage layer and the thickness thereof are represented by Ms (emu/cc) and t (nm), respectively, (1489/Ms)?0.593<t<(6820/Ms)?1.55 holds.Type: GrantFiled: May 1, 2012Date of Patent: January 7, 2014Assignee: Sony CorporationInventors: Yutaka Higo, Masanori Hosomi, Hiroyuki Ohmori, Kazuhiro Bessho, Tetsuya Asayama, Kazutaka Yamane, Hiroyuki Uchida
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Patent number: 8625341Abstract: Spin Transfer Torque Magnetoresistive Random Access Memory (STT-MRAM) bit cells are disclosed. The bit cells include a source line formed in a first plane and a bit line formed in a second plane. The bit line has a longitudinal axis that is parallel to a longitudinal axis of the source line, and the source line overlaps at least a portion of the bit line.Type: GrantFiled: April 17, 2012Date of Patent: January 7, 2014Assignee: QUALCOMM IncorporatedInventor: William H. Xia
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Patent number: 8611147Abstract: A spin-torque transfer memory random access memory (STTMRAM) element, employed in a STTMRAM array, receives electric current for storage of digital information, the STTMRAM element has a magnetic tunnel junction (MTJ). The MTJ includes an anti-ferromagnetic (AF) layer, a fixed layer having a magnetization that is substantially fixed in one direction and that comprises a first magnetic layer, an AF coupling layer and a second magnetic layer, a barrier layer formed upon the fixed layer, and a free layer. The free layer is synthetic and has a high-polarization magnetic layer, a low-crystallization magnetic layer, a non-magnetic separation layer, and a magnetic layer, wherein during a write operation, a bidirectional electric current is applied across the STTMRAM element to switch the magnetization of the free layer between parallel and anti-parallel states relative to the magnetization of the fixed layer.Type: GrantFiled: March 22, 2013Date of Patent: December 17, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Roger Klas Malmhall, Yiming Huai
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Patent number: 8611139Abstract: There is disclosed a memory element including a layered structure including a memory layer that has a magnetization perpendicular to a film face; a magnetization-fixed layer; and an insulating layer provided between the memory layer. An electron that is spin-polarized is injected in a lamination direction of a layered structure, a magnitude of an effective diamagnetic field which the memory layer receives is smaller than a saturated magnetization amount of the memory layer, in regard to the insulating layer that comes into contact with the memory layer, and the other side layer with which the memory layer comes into contact at a side opposite to the insulating layer, at least an interface that comes into contact with the memory layer is formed of an oxide film, and the memory layer includes at least one of non-magnetic metal and oxide in addition to a Co—Fe—B magnetic layer.Type: GrantFiled: September 7, 2011Date of Patent: December 17, 2013Assignee: Sony CorporationInventors: Kazutaka Yamane, Masanori Hosomi, Hiroyuki Ohmori, Kazuhiro Bessho, Yutaka Higo, Hiroyuki Uchida
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Patent number: 8593863Abstract: A magnetic resistance memory apparatus capable of implementing various levels and a method of driving the same are provided. The magnetic resistance memory apparatus includes a first magnetic device that includes a fixed layer having a fixed magnetization direction, a tunnel layer disposed on the fixed layer, and a first free layer disposed on the tunnel layer having a variable magnetization direction, and a second magnetic device disposed on the first magnetic device including a plurality of free layers insulated with a spacer layer interposed.Type: GrantFiled: September 23, 2011Date of Patent: November 26, 2013Assignee: Hynix Semiconductor Inc.Inventor: Won Joon Choi
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Patent number: 8547737Abstract: A magnetoresistive element according to an embodiment includes: a first ferromagnetic layer having an axis of easy magnetization in a direction perpendicular to a film plane; a second ferromagnetic layer having an axis of easy magnetization in a direction perpendicular to a film plane; a nonmagnetic layer placed between the first ferromagnetic layer and the second ferromagnetic layer; a first interfacial magnetic layer placed between the first ferromagnetic layer and the nonmagnetic layer; and a second interfacial magnetic layer placed between the second ferromagnetic layer and the nonmagnetic layer. The first interfacial magnetic layer includes a first interfacial magnetic film, a second interfacial magnetic film placed between the first interfacial magnetic film and the nonmagnetic layer and having a different composition from that of the first interfacial magnetic film, and a first nonmagnetic film placed between the first interfacial magnetic film and the second interfacial magnetic film.Type: GrantFiled: September 27, 2012Date of Patent: October 1, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Tadaomi Daibou, Eiji Kitagawa, Yutaka Hashimoto, Masaru Tokou, Toshihiko Nagase, Katsuya Nishiyama, Koji Ueda, Makoto Nagamine, Tadashi Kai, Hiroaki Yoda
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Patent number: 8542526Abstract: A method of making a magnetic random access memory cell includes forming a magnetic tunnel junction (MTJ) on top of a wafer, depositing oxide on top of the MTJ, depositing a photo-resist layer on top of the oxide layer, forming a trench in the photo-resist layer and oxide layer where the trench has a width that is substantially the same as that of the MTJ. Then, the photo-resist layer is removed and a hard mask layer is deposited on top of the oxide layer in the trench and the wafer is planarized to remove the portion of the hard mask layer that is not in the trench to substantially level the top of oxide layer and the hard layer on the wafer. The remaining oxide layer is etched and the MTJ is etched to remove the portion of the MTJ which is not covered by the hard mask layer.Type: GrantFiled: February 8, 2013Date of Patent: September 24, 2013Assignee: Avalanche Technology, Inc.Inventors: Parviz Keshtbod, Roger Klas Malmhall, Rajiv Yadav Ranjan
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Patent number: 8542524Abstract: A method of making a magnetic random access memory cell includes forming a magnetic tunnel junction (MTJ) on top of a wafer, depositing oxide on top of the MTJ, depositing a photo-resist layer on top of the oxide layer, forming a trench in the photo-resist layer and oxide layer where the trench has a width that is substantially the same as that of the MTJ. Then, the photo-resist layer is removed and a hard mask layer is deposited on top of the oxide layer in the trench and the wafer is planarized to remove the portion of the hard mask layer that is not in the trench to substantially level the top of oxide layer and the hard layer on the wafer. The remaining oxide layer is etched and the MTJ is etched to remove the portion of the MTJ which is not covered by the hard mask layer.Type: GrantFiled: December 21, 2010Date of Patent: September 24, 2013Assignee: Avalanche Technology, Inc.Inventors: Parviz Keshtbod, Roger Klas Malmhall, Rajiv Yadav Ranjan
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Patent number: 8531876Abstract: A memory unit includes a magnetic tunnel junction data cell electrically coupled to a bit line and a word line. The magnetic tunnel junction data cell is configured to switch between a high resistance state and a low resistance state by passing a unipolar voltage across the magnetic tunnel junction data cell. A diode is electrically coupled between the magnetic tunnel junction data cell and the word line or bit line. A voltage source provides the unipolar voltage across the magnetic tunnel junction data cell that writes the high resistance state and the low resistance state.Type: GrantFiled: June 20, 2012Date of Patent: September 10, 2013Assignee: Seagate Technology LLCInventors: Xiaohua Lou, Haiwen Xi
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Publication number: 20130228884Abstract: A magnetic tunnel junction having a ferromagnetic free layer and a ferromagnetic pinned reference layer, each having an out-of-plane magnetic anisotropy and an out-of-plane magnetization orientation, the ferromagnetic free layer switchable by spin torque. The magnetic tunnel junction includes a ferromagnetic assist layer proximate the free layer, the assist layer having a low magnetic anisotropy less than 700 Oe and positioned to apply a magnetic field on the free layer.Type: ApplicationFiled: April 5, 2013Publication date: September 5, 2013Applicant: SEAGATE TECHNOLOGY LLCInventors: Yuankai Zheng, Zheng Gao, Wonjoon Jung, Xuebing Feng, Xiaohue Lou, Haiwen Xi
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Patent number: 8526224Abstract: A compound magnetic data storage cell, applicable to spin-torque random access memory (ST-RAM), is disclosed. A magnetic data storage cell includes a magnetic storage element and two terminals communicatively connected to the magnetic storage element. The magnetic storage element is configured to yield any of at least three distinct magnetoresistance output levels, corresponding to stable magnetic configurations, in response to spin-momentum transfer inputs via the terminals.Type: GrantFiled: October 29, 2012Date of Patent: September 3, 2013Assignee: Seagate Technology LLCInventors: Thomas William Clinton, Werner Scholz
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Patent number: 8520433Abstract: A magnetoresistive element according to an embodiment includes a first magnetic layer, a second magnetic layer, and a first nonmagnetic layer provided between the first magnetic layer and the second magnetic layer, at least one of the first magnetic layer and the second magnetic layer including a magnetic film of MnxAlyGez (10 atm %?x?44 atm %, 10 atm %?y?65 atm %, 10 atm %?z?80 atm %, x+y+z=100 atm %).Type: GrantFiled: September 20, 2012Date of Patent: August 27, 2013Assignees: Kabushiki Kaisha Toshiba, Tohoku UniversityInventors: Yushi Kato, Tadaomi Daibou, Eiji Kitagawa, Takahide Kubota, Shigemi Mizukami, Terunobu Miyazaki
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Patent number: 8514618Abstract: The present disclosure concerns a magnetic random access memory MRAM cell comprising a tunnel magnetic junction formed from a first ferromagnetic layer, a second ferromagnetic layer having a second magnetization that can be oriented relative to an anisotropy axis of the second ferromagnetic layer at a predetermined high temperature threshold, and a tunnel barrier; a first current line extending along a first direction and in communication with the magnetic tunnel junction; the first current line being configured to provide an magnetic field for orienting the second magnetization when carrying a field current; wherein the MRAM cell is configured with respect to the first current line such that when providing the magnetic field, at least a component of the magnetic field is substantially perpendicular to said anisotropy axis. The MRAM cell has an improved switching efficiency, lower power consumption and improved dispersion of the switching field compared to conventional MRAM cells.Type: GrantFiled: July 10, 2012Date of Patent: August 20, 2013Assignee: Crocus-Technology SAInventors: Lucien Lombard, Ioan Lucian Prejbeanu
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Patent number: 8514619Abstract: A magnetic memory device includes: a free layer for storing information; and a reference layer disposed on a first surface of the free layer. The reference layer includes at least two magnetic domains and a magnetic domain wall between the at least two magnetic domains. The reference layer extends past both ends of the free layer. The magnetic memory device further includes a switching element connected to a second surface of the free layer. Another magnetic memory device includes: a first reference layer having a first magnetic domain wall; a second reference layer having a second magnetic domain wall; and a memory structure between the first and second reference layers. The memory structure includes: a first free layer adjacent to the first reference layer; a second free layer adjacent to the second reference layer; and a switching element between the first and second free layers.Type: GrantFiled: September 3, 2010Date of Patent: August 20, 2013Assignee: Samsung Electronics Co., Ltd.Inventor: In-jun Hwang
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Patent number: 8503225Abstract: Method for writing and reading more than two data bits to a MRAM cell comprising a magnetic tunnel junction formed from a read magnetic layer having a read magnetization, and a storage layer comprising a first storage ferromagnetic layer having a first storage magnetization, a second storage ferromagnetic layer having a second storage magnetization; the method comprising: heating the magnetic tunnel junction above a high temperature threshold; and orienting the first storage magnetization at an angle with respect to the second storage magnetization such that the magnetic tunnel junction reaches a resistance state level determined by the orientation of the first storage magnetization relative to that of the read magnetization. The method allows for storing at least four distinct state levels in the MRAM cell using only one current line to generate a writing field.Type: GrantFiled: May 18, 2012Date of Patent: August 6, 2013Assignee: Crocus-Technology SAInventors: Lucien Lombard, Ioan Lucian Prejbeanu
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Patent number: 8503223Abstract: In a memory, the MTJ elements respectively have a first end electrically connected to any one of a source and a drain of one of the cell transistors. First bit lines each of which is electrically connected to the other one of the source and the drain of one of the cell transistors. Second bit lines each of which is electrically connected to a second end of one of the MTJ elements. Word lines each of which is electrically connected to a gate of one of the cell transistors or functions as a gate of one of the cell transistors. A plurality of the second bit lines correspond to one of the first bit lines. A plurality of the MTJ elements share the same word line and the same active area. The active area is continuously formed in an extending direction of the first and second bit lines.Type: GrantFiled: March 19, 2012Date of Patent: August 6, 2013Assignee: Kabushiki Kaisha ToshibaInventor: Susumu Shuto
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Patent number: 8503217Abstract: A two-dimensional array of switching devices comprises a plurality of crossbar tiles. Each crossbar tile has a plurality of row wire segments intersecting a plurality of column wire segments, and a plurality of switching devices each formed at an intersection of a row wire segment and a column wire segment. The array has a plurality of lateral latches disposed in a plane of the switching devices. Each lateral latch is linked to a first wire segment of a first crossbar tile and a second wire segment of a second crossbar tile opposing the first wire segment. The lateral latch is operable to close or open to form or break an electric connection between the first and second wire segments.Type: GrantFiled: April 30, 2011Date of Patent: August 6, 2013Assignee: Hewlett-Packard Development Company, L.P.Inventors: Wei Yi, Gilberto Medeiros Ribeiro, R. Stanley Williams
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Patent number: 8498149Abstract: A non-volatile magnetic memory element includes a number of layers one of which is a free layer which is graded. The graded free layer may include various elements with each element having a different anisotropy or it may include nonmagnetic compounds and magnetic regions with the non-magnetic compounds forming graded contents forming a unique shape such as cone shaped, diamond shaped or other shapes and whose thickness is based on the reactivity of the magnetic compound.Type: GrantFiled: May 21, 2012Date of Patent: July 30, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Parviz Keshtbod, Roger Klas Malmhall
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Patent number: 8498150Abstract: A non-volatile magnetic memory element includes a number of layers one of which is a free layer which is graded. The graded free layer may include various elements with each element having a different anisotropy or it may include nonmagnetic compounds and magnetic regions with the non-magnetic compounds forming graded contents forming a unique shape such as cone shaped, diamond shaped or other shapes and whose thickness is based on the reactivity of the magnetic compound.Type: GrantFiled: May 21, 2012Date of Patent: July 30, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Parviz Keshtbod, Roger Klas Malmhall
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Patent number: 8498148Abstract: A non-volatile magnetic memory element includes a number of layers one of which is a free layer which is graded. The graded free layer may include various elements with each element having a different anisotropy or it may include nonmagnetic compounds and magnetic regions with the non-magnetic compounds forming graded contents forming a unique shape such as cone shaped, diamond shaped or other shapes and whose thickness is based on the reactivity of the magnetic compound.Type: GrantFiled: May 18, 2012Date of Patent: July 30, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Parviz Keshtbod, Roger Klas Malmhall
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Patent number: 8493777Abstract: A non-volatile current-switching magnetic memory element includes a bottom electrode, a pinning layer formed on top of the bottom electrode, and a fixed layer formed on top of the pinning layer. The non-volatile current-switching magnetic memory element further includes a tunnel layer formed on top of the pinning layer, a first free layer with a perpendicular anisotropy that is formed on top of the tunnel layer, a granular film layer formed on top of the free layer, a second free layer formed on top of the granular film layer, a cap layer formed on top of the second layer, and a top electrode formed on top of the cap layer.Type: GrantFiled: April 23, 2012Date of Patent: July 23, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Parviz Keshtbod
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Patent number: 8493779Abstract: A non-volatile magnetic memory element includes a number of layers one of which is a free layer which is graded. The graded free layer may include various elements with each element having a different anisotropy or it may include nonmagnetic compounds and magnetic regions with the non-magnetic compounds forming graded contents forming a unique shape such as cone shaped, diamond shaped or other shapes and whose thickness is based on the reactivity of the magnetic compound.Type: GrantFiled: May 18, 2012Date of Patent: July 23, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Parviz Keshtbod, Roger Klas Malmhall
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Patent number: 8493778Abstract: A non-volatile magnetic memory element includes a number of layers one of which is a free layer which is graded. The graded free layer may include various elements with each element having a different anisotropy or it may include nonmagnetic compounds and magnetic regions with the non-magnetic compounds forming graded contents forming a unique shape such as cone shaped, diamond shaped or other shapes and whose thickness is based on the reactivity of the magnetic compound.Type: GrantFiled: May 18, 2012Date of Patent: July 23, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Parviz Keshtbod, Roger Klas Malmhall
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Patent number: 8493780Abstract: A non-volatile magnetic memory element includes a number of layers one of which is a free layer which is graded. The graded free layer may include various elements with each element having a different anisotropy or it may include nonmagnetic compounds and magnetic regions with the non-magnetic compounds forming graded contents forming a unique shape such as cone shaped, diamond shaped or other shapes and whose thickness is based on the reactivity of the magnetic compound.Type: GrantFiled: May 21, 2012Date of Patent: July 23, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Parviz Keshtbod, Roger Klas Malmhall
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Patent number: 8488376Abstract: A non-volatile magnetic memory element includes a number of layers one of which is a free layer which is graded. The graded free layer may include various elements with each element having a different anisotropy or it may include nonmagnetic compounds and magnetic regions with the non-magnetic compounds forming graded contents forming a unique shape such as cone shaped, diamond shaped or other shapes and whose thickness is based on the reactivity of the magnetic compound.Type: GrantFiled: May 21, 2012Date of Patent: July 16, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Parviz Keshtbod, Roger Klas Malmhall
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Patent number: 8488375Abstract: According to one embodiment, a magnetic recording element includes a stacked body including a first stacked unit and a second stacked unit. The first stacked unit includes a first ferromagnetic layer, a second ferromagnetic layer and a first nonmagnetic layer. Magnetization of the first ferromagnetic layer is substantially fixed in a first direction being perpendicular to a first ferromagnetic layer surface. The second stacked unit includes a third ferromagnetic layer, a fourth ferromagnetic layer and a second nonmagnetic layer. Magnetization of the fourth ferromagnetic layer is substantially fixed in a second direction being perpendicular to a fourth ferromagnetic layer surface. The first direction is opposite to the second direction.Type: GrantFiled: March 1, 2011Date of Patent: July 16, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Daisuke Saida, Minoru Amano, Junichi Ito, Yuichi Ohsawa, Saori Kashiwada, Chikayoshi Kamata, Shigeki Takahashi
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Patent number: 8477530Abstract: A non-uniform switching based non-volatile magnetic memory element includes a fixed layer, a barrier layer formed on top of the fixed layer, a first free layer formed on top of the barrier layer, a non-uniform switching layer (NSL) formed on top of the first free layer, and a second free layer formed on top of the non-uniform switching layer. Switching current is applied, in a direction that is substantially perpendicular to the fixed layer, barrier layer, first free layer, non-uniform switching layer and the second free layer causing switching between states of the first free layer, second free layer and non-uniform switching layer with substantially reduced switching current.Type: GrantFiled: November 28, 2011Date of Patent: July 2, 2013Assignee: Avalanche Technology, Inc.Inventors: Rajiv Yadav Ranjan, Petro Estakhri, Mahmud Assar, Parviz Keshtbod
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Patent number: 8477529Abstract: A magnetic random access memory (MRAM) cell includes an embedded MRAM and an access transistor. The embedded MRAM is formed on a number of metal-interposed-in-interlayer dielectric (ILD) layers, which each include metal dispersed therethrough and are formed on top of the access transistor. An magneto tunnel junction (MTJ) is formed on top of a metal formed in the ILD layers that is in close proximity to a bit line. An MTJ mask is used to pattern the MTJ and is etched to expose the MTJ. Ultimately, metal is formed on top of the bit line and extended to contact the MTJ.Type: GrantFiled: September 19, 2012Date of Patent: July 2, 2013Assignee: Avalanche Technology, Inc.Inventors: Parviz Keshtbod, Ebrahim Abedifard
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Patent number: 8456901Abstract: A system includes a processor and a memory array connected to the processor comprising a first memory cell comprising a first magnetic tunnel junction device having a first terminal connected to a first bit line and a second terminal, and a first field effect transistor having a source terminal connected to a second bit line, a gate terminal connected to a word line, and a drain terminal connected to the second terminal of the first magnetic tunnel junction device, and a second memory cell comprising a second magnetic tunnel junction device having a first terminal connected to a third bit line and a second terminal, and a second field effect transistor having a source terminal connected to the second bit line, a gate terminal connected to the word line, and a drain terminal connected to the second terminal of the second magnetic tunnel junction device.Type: GrantFiled: July 27, 2012Date of Patent: June 4, 2013Assignee: International Business Machines CorporationInventors: John K. DeBrosse, Yutaka Nakamura
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Patent number: 8456899Abstract: A method for operating a memory array device, includes initiating a write “0” state in the device, wherein the initiating the write “0” state includes inducing a first voltage in a word line of the device; and inducing a second voltage in a first bit line (BLTE) of the device.Type: GrantFiled: July 26, 2012Date of Patent: June 4, 2013Assignee: International Business Machines CorporationInventors: John K. DeBrosse, Yutaka Nakamura
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Patent number: 8456893Abstract: A MTJ that minimizes spin-transfer magnetization switching current (Jc) in a Spin-RAM to <1×106 A/cm2 is disclosed. The MTJ has a Co60Fe20B20/MgO/Co60Fe20B20 configuration where the CoFeB AP1 pinned and free layers are amorphous and the crystalline MgO tunnel barrier is formed by a ROX or NOX process. The capping layer preferably is a Hf/Ru composite where the lower Hf layer serves as an excellent oxygen getter material to reduce the magnetic “dead layer” at the free layer/capping layer interface and thereby increase dR/R, and lower He and Jc. The annealing temperature is lowered to about 280° C. to give a smoother CoFeB/MgO interface and a smaller offset field than with a 350° C. annealing. In a second embodiment, the AP1 layer has a CoFeB/CoFe configuration wherein the lower CoFeB layer is amorphous and the upper CoFe layer is crystalline to further improve dR/R and lower RA to ?10 ohm/?m2.Type: GrantFiled: September 15, 2009Date of Patent: June 4, 2013Assignee: MagIC Technologies, Inc.Inventors: Cheng T. Horng, Ru-Ying Tong
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Patent number: 8446757Abstract: A memory array device comprising a first memory cell comprising a first magnetic tunnel junction device having a first terminal connected to a first bit line (BLTE) and a second terminal, and a first field effect transistor (FET) having a source terminal connected to a second bit line (BLC), a gate terminal connected to a word line (WL), and a drain terminal connected to the second terminal of the first magnetic tunnel junction device, and a second memory cell comprising, a second magnetic tunnel junction device having a first terminal connected to a third bit line (BLT0) and a second terminal, and a second field effect transistor (FET) having a source terminal connected to the second bit line (BLC), a gate terminal connected to the word line (WL), and a drain terminal connected to the second terminal of the second magnetic tunnel junction device.Type: GrantFiled: August 18, 2010Date of Patent: May 21, 2013Assignee: International Business Machines CorporationInventors: John K. DeBrosse, Yutaka Nakamura
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Patent number: 8441844Abstract: A method of writing in a memory device comprising a plurality of MRAM cells, each cell including a magnetic tunnel junction having a resistance that can be varied during a write operation when heated at a high threshold temperature; a plurality of word lines connecting cells along a row; and a plurality of bit lines connecting cells along a column; the method comprising supplying a bit line voltage to one of the bit lines and a word line voltage to one of the word lines for passing a heating current through the magnetic tunnel junction of a selected cell; said word line voltage is a word line overdrive voltage being higher than the core operating voltage of the cells such that the heating current has a magnitude that is high enough for heating the magnetic tunnel junction at the predetermined high threshold temperature. The memory device can be written with low power consumption.Type: GrantFiled: June 8, 2011Date of Patent: May 14, 2013Assignee: Crocus Technology SAInventors: Mourad El Baraji, Neal Berger
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Patent number: 8437180Abstract: A memory includes: a memory device that has a memory layer storing data as a magnetization state of a magnetic body and a magnetization fixed layer whose direction of magnetization is fixed through a nonmagnetic layer interposed between the memory layer and the magnetization fixed layer and stores the data in the memory layer by changing a magnetization direction of the memory layer when a write current flowing in a stacked direction of the memory layer and the magnetization fixed layer is applied; and a voltage control unit that supplies the write current configured by independent pulse trains of two or more to the memory device by using a write voltage that is configured by independent pulse trains of two or more.Type: GrantFiled: June 8, 2010Date of Patent: May 7, 2013Assignee: Sony CorporationInventors: Yutaka Higo, Masanori Hosomi, Minoru Ikarashi, Hiroshi Kano, Shinichiro Kusunoki, Hiroyuki Ohmori, Yuki Oishi, Kazutaka Yamane, Tetsuya Yamamoto, Kazuhiro Bessho
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Patent number: 8432727Abstract: In a Spin Transfer Torque Magnetoresistive Random Access Memory (STT-MRAM) a bit cell array can have a source line substantially parallel to a word line. The source line can be substantially perpendicular to bit lines. A source line control unit includes a common source line driver and a source line selector configured to select individual ones of the source lines. The source line driver and source line selector can be coupled in multiplexed relation. A bit line control unit includes a common bit line driver and a bit line selector in multiplexed relation. The bit line control unit includes a positive channel metal oxide semiconductor (PMOS) element coupled between the common source line driver and bit line select lines and bit lines.Type: GrantFiled: April 29, 2010Date of Patent: April 30, 2013Assignees: QUALCOMM Incorporated, Industry-Academic Cooperation Foundation, YonseiInventors: Kyungho Ryu, Jisu Kim, Seong-Ook Jung, Seung H. Kang
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Patent number: 8427866Abstract: There are provided magnetic storage elements capable of performing a high-reliability write operation by inhibiting erroneous reversal of data of the magnetic storage element put in a semi-selected state, and a magnetic storage device using this. A recording layer having an easy axis and a hard axis overlaps at least one of a first or second conductive layer at the entire region thereof in plan view. First endpoints of a first line segment along the easy axis and maximum in dimension overlapping the recording layer in plan view don't overlap the second conductive layer in plan view. At least one of second endpoints of a pair of endpoints of a second line segment passing through the middle point of the first line segment, orthogonal to the first line segment in plan view, and overlapping the recording layer in plan view doesn't overlap the first conductive layer in plan view.Type: GrantFiled: February 15, 2012Date of Patent: April 23, 2013Assignee: Renesas Electronics CorporationInventors: Takashi Takenaga, Takeharu Kuroiwa, Taisuke Furukawa
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Patent number: 8427864Abstract: To write information on a memory cell of SPRAM formed of an MOS transistor and a tunnel magnetoresistive element, the memory cell is supplied with a current in a direction opposite to a direction of a current required for writing the information on the memory cell, and then, the memory cell is supplied with a current required for writing. In this manner, even when the same information is sequentially written on the memory cell, since the currents in the two directions are caused to flow in pairs in the tunnel magnetoresistive element of the memory cell each time information is rewritten, deterioration of a film that forms the tunnel magnetoresistive element can be suppressed. Therefore, reliability of the SPRAM can be improved.Type: GrantFiled: June 2, 2010Date of Patent: April 23, 2013Assignee: Hitachi, Ltd.Inventors: Takayuki Kawahara, Kiyoo Itoh, Riichiro Takemura, Kenchi Ito
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Patent number: 8422276Abstract: Methods are presented for fabricating an MTJ element having a uniform vertical distance between its free layer and a bit line and, in addition, having a protective spacer layer formed abutting the lateral sides of the MTJ element to eliminate leakage currents between MTJ layers and the bit line. Each method forms a dielectric spacer layer on the lateral sides of the MTJ element and, depending on the method, includes an additional layer that protects the spacer layer during etching processes used to form a Cu damascene bit line. At various stages in the process, a dielectric layer is also formed to act as a CMP stop layer so that the capping layer on the MTJ element is not thinned by the CMP process that planarizes the surrounding insulation. Subsequent to planarization, the stop layer is removed by an anisotropic etch of such precision that the MTJ element capping layer is not reduced in thickness and serves to maintain uniform vertical distance between the bit line and the MTJ free layer.Type: GrantFiled: January 20, 2011Date of Patent: April 16, 2013Assignee: MagIC Technologies, Inc.Inventors: Jun Yuan, Liubo Hong, Mao-Min Chen
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Patent number: 8422284Abstract: One embodiment of the present invention includes a three dimensional memory array having a plurality of memory elements coupled to form the array through a single top lead and a single bottom lead, each memory element including a magnetic free layer in which non-volatile data can be stored, wherein each memory element possesses unique resonant frequencies associated with each digital memory state, thereby enabling frequency addressing during parallel write and read operations, each memory element further including a fixed layer and a spacer formed between the free layer and the fixed layer.Type: GrantFiled: December 8, 2009Date of Patent: April 16, 2013Assignee: HGST Netherlands B.V.Inventors: Liesl Folks, Bruce David Terris
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Patent number: 8422285Abstract: A method and system for providing a magnetic junction usable in a magnetic memory are described. The magnetic junction includes first and second pinned layers, first and second nonmagnetic spacer layers, and a free layer. The pinned layers are nonmagnetic layer-free and self-pinned. In some aspects, the magnetic junction is configured to allow the free and second pinned layers to be switched between stable magnetic states when write currents are passed therethrough. The magnetic junction has greater than two stable states. In other aspects, the magnetic junction includes at least third and fourth spacer layers, a second free layer therebetween, and a third pinned layer having a pinned layer magnetic moment, being nonmagnetic layer-free, and being coupled to the second pinned layer. The magnetic junction is configured to allow the free layers to be switched between stable magnetic states when write currents are passed therethrough.Type: GrantFiled: February 23, 2011Date of Patent: April 16, 2013Assignee: Grandis, Inc.Inventors: Dmytro Apalkov, Xueti Tang, Vladimir Nikitin, Alexander A. G. Driskill-Smith, Steven M. Watts, David Druist