Two Magnetic Cells Per Bit Patents (Class 365/131)
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Patent number: 10622069Abstract: A semiconductor memory cell includes a floating body region configured to be charged to a level indicative of a state of the memory cell; a first region in electrical contact with said floating body region; a second region in electrical contact with said floating body region and spaced apart from said first region; and a gate positioned between said first and second regions. The cell may be a multi-level cell. Arrays of memory cells are disclosed for making a memory device. Methods of operating memory cells are also provided.Type: GrantFiled: October 15, 2019Date of Patent: April 14, 2020Assignee: Zeno Semiconductor Inc.Inventor: Yuniarto Widjaja
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Patent number: 10490249Abstract: A data writing method is configured such that a spin device includes a conducting portion extending in a first direction and a device portion stacked on one surface of the conducting portion and including a non-magnetic layer and a ferromagnetic layer, wherein an energy equal to or smaller than an energy represented by a predetermined relational expression (1) is applied in the first direction of the conducting portion when the pulse width of an applied pulse is t.Type: GrantFiled: February 1, 2018Date of Patent: November 26, 2019Assignee: TDK CORPORATIONInventors: Tomoyuki Sasaki, Yohei Shiokawa
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Patent number: 10003012Abstract: This technology provides an electronic device and a method for fabricating the same. An electronic device in accordance with an implementation of this document may include a semiconductor memory, wherein the semiconductor memory may include: a variable resistance element disposed over a substrate and structured to exhibit different resistance states for storing data; and an upper contact plug disposed over the variable resistance element and coupled to the variable resistance element, wherein the upper contact plug includes a first portion that is disposed between an upper end of the upper contact plug and a lower end of the upper contact plug and the first portion has a width smaller than a width of each of the upper end and the lower end.Type: GrantFiled: April 6, 2017Date of Patent: June 19, 2018Assignee: SK hynix Inc.Inventor: Ki-Won Nam
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Patent number: 8917531Abstract: A thermally assisted magnetoresistive random access memory cell, a corresponding array, and a method for fabricating the array. An example cell includes a first metal layer, a second metal layer, an interlayer, a first magnetic stack, and a first non-magnetic via. The first metal layer includes a pad and a first metal line, with the pad not in direct contact with the first metal line. The second metal layer includes a second metal line and a metal strap. The second metal line is perpendicular to the first metal line and not in contact with the metal strap. The interlayer is located between the first and second metal layers. The first metal line is not in direct contact with the interlayer. The first magnetic stack is in direct contact with the interlayer and the metal strap. The first non-magnetic via is in direct contact with the pad and the metal strap.Type: GrantFiled: March 14, 2013Date of Patent: December 23, 2014Assignee: International Business Machines CorporationInventors: Anthony J. Annunziata, John K. DeBrosse
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Patent number: 8908415Abstract: A resistive memory cell includes a switch and a resistive switching device. The switch includes a first terminal connected to a select line and a gate terminal connected to a word line. The resistive switching device is connected between a second terminal of the switch and a bit line. The resistive switching device is resettable by having a positive bias applied to the word line and a negative bias applied to the bit line.Type: GrantFiled: March 1, 2013Date of Patent: December 9, 2014Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventors: Chin-Chieh Yang, Wen-Ting Chu, Kuo-Chi Tu, Yu-Wen Liao, Chih-Yang Chang, Hsia-Wei Chen
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Patent number: 8902632Abstract: Hybrid resistive memory devices and methods of operating and manufacturing the same, include at least two resistive memory units. At least one of the at least two resistive memory units is a resistive memory unit configured to operate in a long-term plasticity state.Type: GrantFiled: December 18, 2012Date of Patent: December 2, 2014Assignees: Samsung Electronics Co., Ltd., Gwangju Institute of Science and TechnologyInventors: Young-bae Kim, Hyun-sang Hwang, Chang-jung Kim
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Patent number: 8869436Abstract: The present disclosure provides one embodiment of a method for operating a resistive random access memory (RRAM) cell. The method includes performing a forming operation to the RRAM cell with a forming voltage; performing a number of set/reset operation cycles to the RRAM cell; and performing a recreating process to the RRAM cell to recover RRAM resistance by applying a recreating voltage. Each of the number of set/reset operation cycles includes a set operation with a set voltage. The recreating voltage is greater than the set voltage.Type: GrantFiled: February 27, 2013Date of Patent: October 28, 2014Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.Inventors: Chun-Yang Tsai, Yu-Wei Ting, Kuo-Ching Huang
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Patent number: 8811062Abstract: A variable resistance memory device has memory cells that are operated by Joule's heat and which are highly thermally efficient. Conductive patterns are formed on a substrate; sacrificial patterns exposing a portion of the top surface of each of the conductive patterns are formed on the conductive patterns, lower electrodes are formed by etching upper portions of the conductive patterns using the sacrificial patterns as an etching mask, then mold patterns are formed on the lower electrodes and cover exposed sidewall surfaces of the sacrificial patterns, and then the sacrificial patterns are replaced with variable resistance patterns.Type: GrantFiled: June 17, 2013Date of Patent: August 19, 2014Assignee: Samsung Electronics Co., Ltd.Inventor: Byeung Chul Kim
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Patent number: 8767456Abstract: An apparatus and associated method for a multi-bit memory capable of being selected with a magnetic layer. Various embodiments of the present invention are generally directed to a first selection layer with a low coercivity that is disposed between first and second storage layers that each have a high coercivity. In response to magnetic saturation of the first selection layer, programming of a logical state to the second storage layer is allowed.Type: GrantFiled: May 16, 2012Date of Patent: July 1, 2014Assignee: Seagate Technology LLCInventors: Nurul Amin, Johannes Van Ek
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Patent number: 8760913Abstract: A magnetic detecting element includes a laminated structure where a fixed magnetic layer and a free magnetic layer are laminated through a non-magnetic material layer, wherein the fixed magnetic layer is a self-pinned type where a first magnetic layer and a second magnetic layer are laminated through a non-magnetic intermediate layer and the first magnetic layer and the second magnetic layer are antiparallelly magnetization-fixed, and the second magnetic layer is in contact with the non-magnetic material layer. The first magnetic layer is formed using FeCo serving as a material having a higher coercive force than the second magnetic layer. The film thickness of the first magnetic layer falls within a range greater than or equal to 10 ? and less than or equal to 17 ?, and is thinner than the film thickness of the second magnetic layer. The non-magnetic intermediate layer is formed using Rh.Type: GrantFiled: December 7, 2012Date of Patent: June 24, 2014Assignee: Alps Electric Co., Ltd.Inventors: Fumihito Koike, Kota Asatsuma
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Patent number: 8755222Abstract: Orthogonal spin-transfer magnetic random access memory (OST-MRAM) uses a spin-polarizing layer magnetized perpendicularly to the free layer to achieve large spin-transfer torques and ultra-fast energy efficient switching. OST-MRAM devices that incorporate a perpendicularly magnetized spin-polarizing layer and a magnetic tunnel junction, which consists of an in-plane magnetized free layer and synthetic antiferromagnetic reference layer, exhibit improved performance over prior art devices. The switching is bipolar, occurring for positive and negative polarity pulses, consistent with a precessional reversal mechanism, and requires an energy less than 450 fJ and may be reliably observed at room temperature with 0.7 V amplitude pulses of 500 ps duration.Type: GrantFiled: November 16, 2011Date of Patent: June 17, 2014Assignee: New York UniversityInventors: Andrew Kent, Daniel Bedau, Huanlong Liu
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Patent number: 8737151Abstract: A low read current architecture for memory. Bit lines of a cross point memory array are allowed to be charged by a selected word line until a minimum voltage differential between a memory state and a reference level is assured.Type: GrantFiled: October 4, 2011Date of Patent: May 27, 2014Assignee: Unity Semiconductor CorporationInventors: Bruce Bateman, Darrell Rinerson, Christophe Chevallier, Chang Hua Siau
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Patent number: 8659938Abstract: A magnetic random access memory (MRAM) cell including a magnetic tunnel junction including a tunnel barrier layer between a first magnetic layer having a first magnetization direction, and a second magnetic layer having a second adjustable magnetization to vary a junction resistance of the magnetic tunnel junction from a first to a second junction resistance level; said magnetic tunnel junction further including a switching resistant element electrically connected to the magnetic tunnel junction and having a switching resistance switchable from a first to a second switching resistance level when a switching current is passed through the switching resistant element, such that a resistance of the MRAM cell can have at least four different cell resistance levels depending of the resistance level of the junction resistance and the switching resistance. The disclosed MRAM cell achieves improved read margin and allows for writing at least four different cell resistance levels.Type: GrantFiled: December 15, 2011Date of Patent: February 25, 2014Assignee: Crocus Technology SAInventor: Ioan Lucian Prejbeanu
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Patent number: 8654576Abstract: Provided is a spin valve element capable of performing multi-value recording, which includes a pair of ferromagnetic layers having different coercivities from each other, and sandwiching an insulating layer or a non-magnetic layer. The ferromagnetic layer having the smaller coercivity has a substantially circular in-plane profile, and a plurality of island-shaped non-magnetic portions IN, IE, IW, and IS are included. In addition, a storage device is manufactured by using such a spin valve element.Type: GrantFiled: September 5, 2008Date of Patent: February 18, 2014Assignee: Fuji Electric Co., Ltd.Inventors: Haruo Kawakami, Yasushi Ogimoto
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Patent number: 8638597Abstract: A memory array includes a plurality of magneto-resistive changing memory cells. Each resistive changing memory cell is electrically between a source line and a bit line and a transistor electrically between the resistive changing memory cell and the bit line. The transistor has a gate electrically between a source region and a drain region and the source region being electrically between the r magneto-resistive changing memory cell and the gate. A word line is electrically coupled to the gate. A bit line charge accumulation sensing for magneto-resistive changing memory is also disclosed.Type: GrantFiled: May 21, 2012Date of Patent: January 28, 2014Assignee: Seagate Technology LLCInventors: Chulmin Jung, Yong Lu, Kang Yong Kim, Young Pil Kim
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Patent number: 8619450Abstract: A method of adjusting a resistive change element using a reference is disclosed. The method comprises inspecting a resistive change element to determine a first state; comparing the first state to a reference wherein said reference provides stimulus parameters corresponding to a transition from the first state to a second state; and applying the stimulus parameters to the resistive change element. A resistive change memory cell array is also disclosed.Type: GrantFiled: September 1, 2010Date of Patent: December 31, 2013Assignee: Nantero Inc.Inventor: Darlene Hamilton
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Patent number: 8599598Abstract: In one aspect, a memory circuit is provided. The memory circuit includes a first three-terminal (3T) resistive memory device and a second 3T resistive memory device coupled to the first 3T resistive memory device. In another aspect a memory array with memory circuits having 3T devices is provided. In yet another aspect, a method of programming a memory array is provided.Type: GrantFiled: November 2, 2011Date of Patent: December 3, 2013Assignee: Altera CorporationInventors: Rakesh H. Patel, Shankar Prasad Sinha
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Patent number: 8576605Abstract: A nonvolatile semiconductor memory device according to an embodiment includes a memory cell array configured by plural memory cells each including a variable resistor and each provided between first and second lines. A control circuit applies to a memory cell through the first and second lines a writing voltage for writing data or a reading voltage for reading data. A sense amplifier circuit senses data retained in a memory cell based on a current flowing through the first line. In a data writing operation, the control circuit applies a writing voltage to each of n number of memory cells configuring one unit such that the memory cells may be supplied with different resistance values. In a data reading operation, the sense amplifier circuit compares level relationship of the resistance values of n number of memory cells configuring one unit and reads out n! patterns of data from the one unit.Type: GrantFiled: March 18, 2011Date of Patent: November 5, 2013Assignee: Kabushiki Kaisha ToshibaInventor: Takahiko Sasaki
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Patent number: 8553451Abstract: Techniques are provided for programming a spin torque transfer magnetic random access memory (STT-MRAM) cell using a unidirectional and/or symmetrical programming current. A unidirectional programming current flows through the free region of the STT-MRAM cell in one direction to switch the magnetization of the free region in at least two different directions. A symmetrical programming current switches the magnetization of the free region to either of the two different directions using a substantially similar current magnitude. In some embodiments, the STT-MRAM cell includes two fixed regions, each having fixed magnetizations in opposite directions and a free region configured to be switched in magnetization to be either parallel with or antiparallel to the magnetization of one of the fixed regions. Switching the free region to different magnetization directions may involve directing the programming current through one of the two oppositely magnetized fixed regions.Type: GrantFiled: June 24, 2011Date of Patent: October 8, 2013Assignee: Micron Technology, Inc.Inventor: Jun Liu
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Patent number: 8456888Abstract: A semiconductor memory device with a variable resistance element includes a plurality of active areas isolated from one another by an isolation layer formed in a substrate, a plurality of word lines crossing over the plurality of active areas, an auxiliary source line disposed between two selected word lines and commonly connected to at least two active areas among the plurality of active areas between the two selected word lines, and a plurality of contact plugs each connected to a corresponding active area.Type: GrantFiled: October 7, 2010Date of Patent: June 4, 2013Assignee: Hynix Semiconductor Inc.Inventor: Seung Hyun Lee
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Patent number: 8395935Abstract: A programmable memory array is disclosed in which the phase change memory cells are self-aligned at the access devices and at the cross-points of the bit lines and the word lines. A method for making the array employs one line mask to define the bit lines and another line mask to define the word lines. The front end of line (FEOL) memory cell elements are in the same layer as the polysilicon gates. The bit lines and the word lines intersect over the devices, and the memory cell elements are formed at the intersections of the bit lines and the word line.Type: GrantFiled: October 6, 2010Date of Patent: March 12, 2013Assignee: Macronix International Co., Ltd.Inventors: Hsiang-Lan Lung, Erh-Kun Lai
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Patent number: 8374048Abstract: 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: GrantFiled: August 11, 2010Date of Patent: February 12, 2013Assignee: Grandis, Inc.Inventor: Dmytro Apalkov
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Patent number: 8363448Abstract: According to one embodiment, a semiconductor memory device includes a memory cell, a power supply circuit, an interconnection and a discharging circuit. The memory cell includes a variable resistance element whose resistance varies by application of a voltage. The power supply circuit outputs the voltage to be applied to the memory cell. The interconnection is formed between the power supply circuit and the memory cell and supplies the voltage output from the power supply circuit to the memory cell. The discharging circuit is connected to the interconnection. The discharging circuit discharges electric charge accumulated in the interconnection after a first operation of applying the voltage to the memory cell is ended and before a second operation of applying the voltage to the memory cell next is started.Type: GrantFiled: September 1, 2010Date of Patent: January 29, 2013Assignee: Kabushiki Kaisha ToshibaInventor: Takafumi Shimotori
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Patent number: 8363465Abstract: A high speed and low power method to control and switch the magnetization direction and/or helicity of a magnetic region in a magnetic device for memory cells using spin polarized electrical current. The mapetic device comprises a reference magnetic layer with a fixed magnetic helicity and/or magnetization direction and a free magnetic layer with a changeable magnetic helicity and/or magnetization direction. The fixed magnetic layer and the free magnetic layer are preferably separated by a non-magnetic layer. The fixed and free magnetic layers may have magnetization directions at a substantially nonzero angle relative to the layer normal. A current can be applied to the device to induce a torque that alters the magnetic state of the device so that it can act as a magnetic memory for writing information. The resistance, which depends on the magnetic state of the device, is measured to read out the information stored in the device.Type: GrantFiled: March 4, 2011Date of Patent: January 29, 2013Assignee: New York UniversityInventors: Andrew Kent, Daniel Stein, Jean-Marc Beaujour
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Patent number: 8355274Abstract: A current steering element which can prevent occurrence of write disturb even when electric pulses having different polarities are applied and can cause large current to flow through a variable resistance element, and with which data can be written without problem. In a storage element (3) including: a variable resistance element (1) whose electric resistance value changes in response to application of electric pulses having a positive polarity and a negative polarity and which maintains the changed electric resistance value; and the current steering element (2) that steers current flowing through the variable resistance element (1) when the electric pulses are applied, the current steering element (2) includes: a first electrode (32); a second electrode (31); and a current steering layer (33) interposed between the first electrode (32) and the second electrode (31). When the current steering layer (33) includes SiNx (0<x?0.Type: GrantFiled: September 17, 2009Date of Patent: January 15, 2013Assignee: Panasonic CorporationInventors: Koji Arita, Takumi Mikawa, Mitsuteru IIjima, Kenji Tominaga
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Patent number: 8310864Abstract: A memory device is described that comprises a plurality of bit lines and an array of vertical transistors arranged on the plurality of bit lines. A plurality of word lines is formed along rows of vertical transistors in the array which comprise thin film sidewalls of word line material and arranged so that the thin film sidewalls merge in the row direction, and do not merge in the column direction, to form word lines. The word lines provide “surrounding gate” structures for embodiments in which the vertical transistors are field effect transistors. Memory elements are formed in electrical communication with the vertical transistors. A fully self-aligned process is provided in which the word lines and memory elements are aligned with the vertical transistors without additional patterning steps.Type: GrantFiled: June 15, 2010Date of Patent: November 13, 2012Assignees: Macronix International Co., Ltd., International Business Machines CorporationInventors: Hsiang-Lan Lung, Chung H Lam, Erh-Kun Lai, Matthew J. Breitwisch
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Patent number: 8310865Abstract: A semiconductor memory device comprises a memory cell, first and second voltage generating circuits generating first and second voltages, and a control circuit. A memory element and a diode included in the memory cell are connected in series between first and second lines. The first voltage has no temperature dependence, and the second voltage has a temperature dependence opposite to that of a forward voltage of the diode. The control circuit detects a resistance state of the memory element in accordance with a change in current flowing in the memory cell in a state where the first/second voltage is applied to the first/second in a read operation of the memory cell.Type: GrantFiled: October 6, 2010Date of Patent: November 13, 2012Assignee: Elpida Memory Inc.Inventor: Shuichi Tsukada
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Patent number: 8203869Abstract: A memory array includes a plurality of magneto-resistive changing memory cells. Each resistive changing memory cell is electrically between a source line and a bit line and a transistor electrically between the resistive changing memory cell and the bit line. The transistor has a gate electrically between a source region and a drain region and the source region being electrically between the magneto-resistive changing memory cell and the gate. A word line is electrically coupled to the gate. A bit line charge accumulation sensing for magneto-resistive changing memory is also disclosed.Type: GrantFiled: December 2, 2008Date of Patent: June 19, 2012Assignee: Seagate Technology LLCInventors: Chulmin Jung, Yong Lu, Kang Yong Kim, Young Pil Kim
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Patent number: 8199570Abstract: An apparatus and associated method for a multi-bit memory capable of being selected with a magnetic layer. Various embodiments of the present invention are generally directed to a first selection layer with a low coercivity that is disposed between first and second storage layers that each have a high coercivity. In response to magnetic saturation of the first selection layer, programming of a logical state to the second storage layer is allowed.Type: GrantFiled: October 7, 2010Date of Patent: June 12, 2012Assignee: Seagate Technology LLCInventors: Nurul Amin, Johannes Van Ek
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Patent number: 8154905Abstract: A semiconductor memory according to an aspect of the invention including first and second bit lines, a word line, a resistive memory element which has one end and the other end, the one end being connected with the first bit line, a selective switch element which has a current path and a control terminal, one end of the current path being connected with the other end of the resistive memory element, the other end of the current path being connected with the second bit line, the control terminal being connected with the word line, a first column switch connected with the first bit line, a second column switch connected with the second bit line, wherein the first and second bit lines is activated and then the word line is activated when starting writing or reading data with respect to the resistive memory element.Type: GrantFiled: June 25, 2009Date of Patent: April 10, 2012Assignee: Kabushiki Kaisha ToshibaInventor: Tsuneo Inaba
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Patent number: 8151034Abstract: A portion of a nonvolatile memory array that is likely to contain, partially programmed data may be identified from a high sensitivity read, by applying stricter than usual ECC requirements, or using pointers to programmed sectors. The last programmed data may be treated as likely to be partially programmed data. Data in the identified portion may be copied to another location, or left where it is with an indicator to prohibit further programming to the same cells. To avoid compromising previously stored data during subsequent programming, previously stored data may be backed up. Backing up may be done selectively, for example, only for nonsequential data, or only when the previously stored data contains an earlier version of data being programmed. If a backup copy already exists, another backup copy is not created. Sequential commands are treated as a single command if received within a predetermined time period.Type: GrantFiled: February 5, 2008Date of Patent: April 3, 2012Assignee: Sandisk Technologies Inc.Inventors: Sergey A. Gorobets, Alan D. Bennett, Neil D. Hutchison, Shai Traister, Jason T. Lin
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Patent number: 8111541Abstract: A method and structure of a bistable resistance random access memory comprise a plurality of programmable resistance random access memory cells where each programmable resistance random access memory cell includes multiple memory members for performing multiple bits for each memory cell. The bistable RRAM includes a first resistance random access member connected to a second resistance random access member through interconnect metal liners and metal oxide strips. The first resistance random access member has a first resistance value Ra, which is determined from the thickness of the first resistance random access member based on the deposition of the first resistance random access member. The second resistance random access member has a second resistance value Rb, which is determined from the thickness of the second resistance random access member based on the deposition of the second resistance random access member.Type: GrantFiled: March 2, 2010Date of Patent: February 7, 2012Assignee: Macronix International Co., Ltd.Inventors: Erh-Kun Lai, ChiaHua Ho, Kuang Yeu Hsieh
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Patent number: 8077497Abstract: A resistive memory device includes: a storage element; a first line and a second line; a first drive controller; and a second drive controller.Type: GrantFiled: June 14, 2010Date of Patent: December 13, 2011Assignee: Sony CorporationInventor: Kentaro Ogata
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Patent number: 8042082Abstract: The invention relates to multi-planar memory components in a three-dimensional integrated circuit system configuration. A multi-planar memory system consisting of a plurality of memory circuit planes in a three-dimensional system on a chip (3D SoC) comprised of a plurality of memory layers, at least one logic circuit layer and an interface configured to provide access to memory and logic circuit layers.Type: GrantFiled: September 12, 2008Date of Patent: October 18, 2011Inventor: Neal Solomon
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Patent number: 7965544Abstract: An inadvertent write can be prevented when a read is performed. The duration of the write current pulse for writing information in the magnetic memory layer is longer than the duration of the read current pulse for reading the information from the magnetic memory layer.Type: GrantFiled: July 27, 2010Date of Patent: June 21, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Eiji Kitagawa, Masatoshi Yoshikawa, Tatsuya Kishi, Hiroaki Yoda
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Patent number: 7936591Abstract: A word line voltage is applied to a plurality of word lines. A read/write voltage is applied to a plurality of bit lines. The read/write voltage is applied to a plurality of source lines. A word line selector selects the word line and applies the word line voltage. A driver applies a predetermined voltage to the bit line and the source line, thereby supplying a current to the memory cell. A read circuit reads a first current having flowed through the memory cell, and determines data stored in the memory cell. When performing the read, the driver supplies a second current to second bit lines among other bit lines, which are adjacent to the first bit line through which the first current has flowed. The second current generates a magnetic field in a direction to suppress a write error in the memory cell from which data is to be read.Type: GrantFiled: January 21, 2009Date of Patent: May 3, 2011Assignee: Kabushiki Kaisha ToshibaInventors: Kiyotaro Itagaki, Yoshihiro Ueda
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Patent number: 7894249Abstract: A magnetoresistive element includes a free layer a pinned layer; a nonmagnetic layer interposed between the free layer and the pinned layer; and two magnetic layers arranged adjacent to the free layer on an opposite side to the pinned layer. The free layer includes: a first magnetic layer, a second magnetic layer, and a first nonmagnetic layer interposed between the first magnetic layer and the second magnetic layer. Magnetization of the first magnetic layer and magnetization of the second magnetic layer are antiferromagnetically coupled. One of the two magnetic layers is in contact with one end of the free layer in a long-axis direction, and the other of the two magnetic layers is in contact with the other end of the free layer in the long-axis direction.Type: GrantFiled: February 23, 2007Date of Patent: February 22, 2011Assignee: NEC CorporationInventors: Ryusuke Nebashi, Tetsuhiro Suzuki
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Patent number: 7864564Abstract: Between the value of an electric current and the supply duration for which the electric current is supplied that cause magnetization reversal, there is the relation of monotonous decrease. This means that, as the supply duration is shortened, the threshold current value for causing the magnetization reversal is larger. Therefore, in terms of suppressing occurrence of read disturb, the read current supply duration may be shortened to increase the threshold value of the current causing the magnetization reversal and thereby ensure a sufficient read disturb margin. Therefore, the read current supply duration may be shortened relative to the write current supply duration ensure the read disturb margin and suppress occurrence of read disturb.Type: GrantFiled: December 14, 2009Date of Patent: January 4, 2011Assignee: Renesas Electronics CorporationInventor: Hideto Hidaka
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Patent number: 7826260Abstract: A spin-transfer torque memory apparatus and self-reference read and write assist schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage and storing the first bit line read voltage. A magnetic field is applied through the free magnetic layer the forming a magnetic field modified magnetic tunnel junction data cell, the magnetic field rotates the magnetization orientation of the free magnetic layer without switching a resistance state of the magnetic tunnel junction data cell.Type: GrantFiled: February 17, 2009Date of Patent: November 2, 2010Assignee: Seagate Technology LLCInventors: Wenzhong Zhu, Yiran Chen, Xiaobin Wang, Zheng Gao, Haiwen Xi, Dimitar V. Dimitrov
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Patent number: 7813168Abstract: A spin-transfer torque memory apparatus and self-reference read and write assist schemes are described. One method of self-reference reading a spin-transfer torque memory unit includes applying a first read current through a magnetic tunnel junction data cell and forming a first bit line read voltage and storing the first bit line read voltage. A magnetic field is applied through the magnetic tunnel junction data cell forming a magnetic field modified magnetic tunnel junction data cell. Then a second read current is applied thorough the magnetic field modified magnetic tunnel junction data cell forming a second bit line read voltage and the bit line read voltage is stored and compared with the first bit line read voltage to determine whether the first resistance state of the magnetic tunnel junction data cell was a high resistance state or low resistance state. Methods of applying a magnetic field to the MTJ and then writing the desired resistance state are also disclosed.Type: GrantFiled: February 17, 2009Date of Patent: October 12, 2010Assignee: Seagate Technology LLCInventors: Wenzhong Zhu, Yiran Chen, Dimitar V. Dimitrov, Xiaobin Wang
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Patent number: 7791920Abstract: The present invention provides a method for providing magnetic shielding for a circuit comprising magnetically sensitive materials, comprising actively shielding the circuit from a disturbing magnetic field. A corresponding semiconductor device is also provided. The method and device allows shielding for strong disturbing magnetic fields.Type: GrantFiled: November 25, 2008Date of Patent: September 7, 2010Assignee: NXP B.V.Inventor: Kars-Michiel Hubert Lenssen
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Patent number: 7787288Abstract: An inadvertent write can be prevented when a read is performed. The duration of the write current pulse for writing information in the magnetic memory layer is longer than the duration of the read current pulse for reading the information from the magnetic memory layer.Type: GrantFiled: July 27, 2007Date of Patent: August 31, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Eiji Kitagawa, Masatoshi Yoshikawa, Tatsuya Kishi, Hiroaki Yoda
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Patent number: 7778062Abstract: A resistance change memory device including: a semiconductor substrate; at least one cell array formed above the semiconductor substrate, each memory cell having a stack structure of a variable resistance element and an access element, the access element having such an off-state resistance value in a certain voltage range that is ten times or more as high as that in a select state; and a read/write circuit formed on the semiconductor substrate as underlying the cell array for data reading and writing, wherein the variable resistance element comprises a recording layer composed of a composite compound containing at least two types of cation elements, at least one type of the cation element being a transition element having “d” orbit, in which electrons are incompletely filled, the shortest distance between adjacent cation elements being 0.32 nm or less.Type: GrantFiled: June 12, 2007Date of Patent: August 17, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Haruki Toda, Koichi Kubo
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Patent number: 7755934Abstract: A resistance change memory device including: a substrate; cell arrays stacked thereabove, each including a matrix layout of memory cells; a write circuit configured to write a pair cell constituted by two neighboring memory cells; and a read circuit configured to read complementary resistance value states of the pair cell as one bit of data, wherein the memory cell includes a variable resistance element for storing as information a resistance value, which has a recording layer composed of a composite compound containing at least two types of cation elements, at least one type of the cation element being a transition element having “d”-orbit, in which electrons are incompletely filled, the shortest distance between adjacent cation elements being 0.32 nm or less.Type: GrantFiled: June 12, 2007Date of Patent: July 13, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Haruki Toda, Koichi Kubo
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Patent number: 7729158Abstract: A resistance change memory device including: a semiconductor substrate; cell arrays stacked above the substrate, each having memory cells, bit lines and word lines; a read/write circuit formed on the semiconductor substrate; first and second vertical wirings disposed to connect the bit lines to the read/write circuit; and third vertical wirings disposed the word lines to the read/write circuit. The memory cell includes a variable resistance element for storing as information a resistance value, which has a recording layer composed of a composite compound containing at least two types of cation elements, at least one type of the cation element being a transition element having “d” orbit, in which electrons are incompletely filled, the shortest distance between adjacent cation elements being 0.32 nm or less.Type: GrantFiled: June 11, 2007Date of Patent: June 1, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Haruki Toda, Koichi Kubo
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Patent number: 7719875Abstract: A resistance change memory device including: a substrate; cell arrays stacked thereabove, each including a matrix layout of memory cells; a write circuit configured to write a pair cell constituted by two neighboring memory cells; and a read circuit configured to read complementary resistance value states of the pair cell as one bit of data, wherein the memory cell includes a variable resistance element for storing as information a resistance value, and wherein the variable resistance element has a recording layer formed of a first composite compound expressed by AxMyOz (where “A” and “M” are cation elements different from each other; “O” oxygen; and 0.5?x?1.5, 0.5?y?2.5 and 1.5?z?4.5) and a second composite compound containing at least one transition element and a cavity site for housing a cation ion.Type: GrantFiled: June 12, 2007Date of Patent: May 18, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Haruki Toda, Koichi Kubo
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Patent number: 7706167Abstract: A resistance change memory device including: a substrate; cell arrays stacked thereabove, each including a matrix layout of memory cells; a write circuit configured to write a pair cell constituted by two neighboring memory cells; and a read circuit configured to read complementary resistance value states of the pair cell as one bit of data, wherein the memory cell includes a variable resistance element for storing as information a resistance value. The variable resistance element has: a recording layer formed of a composite compound containing at least one transition element and a cavity site for housing a cation ion; and electrodes formed on the opposite sides of the recording layer, one of the electrodes serving as a cation source in a write or erase mode for supplying a cation to the recording layer to be housed in the cavity site therein.Type: GrantFiled: June 12, 2007Date of Patent: April 27, 2010Assignee: Kabushiki Kaisha ToshibaInventors: Haruki Toda, Koichi Kubo
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Patent number: 7697316Abstract: A bistable resistance random access memory comprises a plurality of programmable resistance random access memory cells where each programmable resistance random access memory cell includes multiple memory members for performing multiple bits for each memory cell. The bistable RRAM includes a first resistance random access member connected to a second resistance random access member through interconnect metal liners and metal oxide strips. The first resistance random access member has a first resistance value Ra, which is determined from the thickness of the first resistance random access member based on the deposition of the first resistance random access member. The second resistance random access member has a second resistance value Rb, which is determined from the thickness of the second resistance random access member based on the deposition of the second resistance random access member.Type: GrantFiled: December 7, 2006Date of Patent: April 13, 2010Assignee: Macronix International Co., Ltd.Inventors: Erh-Kun Lai, ChiaHua Ho, Kuang Yeu Hsieh
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Patent number: 7663915Abstract: A memory cell for storing 1-bit data is formed by using at least two memory elements in the OTP type nonvolatile memory using a memory element that have two states and can transit only in one direction. In the OTP type nonvolatile memory using a memory element that has two states of an H state (a first state) and an L (a second state) state (hereinafter simply referred to as H and L) and can electrically transit only in one direction from L to H, a memory cell for storing 1-bit data is formed by using two or more memory elements.Type: GrantFiled: February 4, 2005Date of Patent: February 16, 2010Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventor: Kiyoshi Kato
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Patent number: 7646627Abstract: Between the value of an electric current and the supply duration for which the electric current is supplied that cause magnetization reversal, there is the relation of monotonous decrease. This means that, as the supply duration is shortened, the threshold current value for causing the magnetization reversal is larger. Therefore, in terms of suppressing occurrence of read disturb, the read current supply duration may be shortened to increase the threshold value of the current causing the magnetization reversal and thereby ensure a sufficient read disturb margin. Therefore, the read current supply duration may be shortened relative to the write current supply duration ensure the read disturb margin and suppress occurrence of read disturb.Type: GrantFiled: May 18, 2007Date of Patent: January 12, 2010Assignee: Renesas Technology Corp.Inventor: Hideto Hidaka