Resistive Patents (Class 365/100)
  • Patent number: 8116116
    Abstract: A resistance RAM includes a first electrode, an oxide layer that is formed on the first electrode, a solid electrolyte layer that is disposed on the oxide layer, and a second electrode that is disposed on the solid electrolyte layer. A method of forming the resistance RAM includes forming a conductive tip in the oxide layer by applying reference voltage to any one of the electrodes of the resistance RAM, and applying foaming voltage to the remaining one, such that the oxide layer is electrically broken. A conductive filament is formed in the solid electrolyte layer by applying a positive voltage to the second electrode, and the conductive filament that is formed in the solid electrolyte layer is removed by applying a negative voltage to the second electrode.
    Type: Grant
    Filed: June 29, 2009
    Date of Patent: February 14, 2012
    Assignee: Gwangju Institute of Science and Technology
    Inventors: Hyun Sang Hwang, Jaesik Yoon
  • Patent number: 8116129
    Abstract: A variable resistance memory device includes a substrate, a plurality of active lines formed on the substrate, are uniformly separated, and extend in a first direction, a plurality of switching devices formed on the active lines and are separated from one another, a plurality of variable resistance devices respectively formed on and connected to the switching devices, a plurality of local bit lines formed on the variable resistance devices, are uniformly separated, extend in a second direction, and are connected to the variable resistance devices, a plurality of local word lines formed on the local bit lines, are uniformly separated, and extend in the first direction, a plurality of global bit lines formed on the local word lines, are uniformly separated, and extend in the second direction, and a plurality of global word lines formed on the global bit lines, are uniformly separated, and extend in the first direction.
    Type: Grant
    Filed: August 31, 2010
    Date of Patent: February 14, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Yu-hwan Ro, Byung-gil Choi, Woo-yeong Cho, Hyung-rok Oh
  • Patent number: 8111541
    Abstract: 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: Grant
    Filed: March 2, 2010
    Date of Patent: February 7, 2012
    Assignee: Macronix International Co., Ltd.
    Inventors: Erh-Kun Lai, ChiaHua Ho, Kuang Yeu Hsieh
  • Patent number: 8111539
    Abstract: A memory system includes a substrate, control circuitry on the substrate, a three dimensional memory array (above the substrate) that includes a plurality of memory cells with reversible resistance-switching elements, and a circuit for detecting the setting and resetting of the reversible resistance-switching elements.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: February 7, 2012
    Assignee: SanDisk 3D LLC
    Inventors: Luca G. Fasoli, Tianhong Yan, Jeffrey Koon Yee Lee
  • Patent number: 8111545
    Abstract: A phase-change memory device and its firing method are provided. The firing method of the phase-change memory device includes applying a writing current to phase-change memory cells, identifying a state of the phase-change memory cells after applying the writing current, and applying a firing current, in which an additional current is added to the writing current, to the phase-change memory cells in accordance with the state.
    Type: Grant
    Filed: September 25, 2007
    Date of Patent: February 7, 2012
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Ki-won Lim, Won-ryul Chung, Young-ran Kim
  • Patent number: 8111544
    Abstract: A method of writing a magneto-resistive random access memory (MRAM) cell includes providing a writing pulse to write a value to the MRAM cell; and verifying a status of the MRAM cell immediately after the step of providing the first writing pulse. In the event of a write failure, the value is rewritten into the MRAM cell.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: February 7, 2012
    Assignee: Taiwan Semiconductor Manufacturing Company, Ltd.
    Inventors: Shine Chung, Hung-Sen Wang, Tao-Wen Chung, Chun-Jung Lin, Yu-Jen Wang
  • Patent number: 8101938
    Abstract: A method of fabricating a chalcogenide memory cell is described. The cross-sectional area of a chalcogenide memory element within the cell is controlled by the thickness of a bottom electrode and the width of a word line. The method allows the formation of ultra small chalcogenide memory cells.
    Type: Grant
    Filed: September 20, 2007
    Date of Patent: January 24, 2012
    Assignee: Macronix International Co., Ltd.
    Inventor: Hsiang-Lan Lung
  • Patent number: 8102699
    Abstract: A memory device includes a substrate and a plurality of cell arrays stacked above the substrate. The cell arrays have bit lines coupled to first ends of memory cells and word lines coupled to the other ends. Each of the memory cells includes a variable resistance element to be set at a resistance value. While a selected bit line is set at a certain potential, word lines coupled to different memory cells, which are coupled in common to the selected bit line, are sequentially driven, so that different memory cells are accessed in a time-divisional mode.
    Type: Grant
    Filed: December 13, 2010
    Date of Patent: January 24, 2012
    Assignee: Kabushiki Kaisha Toshiba
    Inventor: Haruki Toda
  • Patent number: 8098513
    Abstract: The present disclosure relates to memory arrays with read reference voltage cells. In particular the present disclosure relates to variable resistive memory cell apparatus and arrays that include a high resistance state reference memory cell and a low resistance state reference memory cell that provides a reliable average reference voltage on chip to compare to a read voltage of a selected memory cell and determine if the selected memory cell is in the high resistance state or low resistance state. These memory arrays are particularly suitable for use with spin-transfer torque memory cells and resolves many systematic issues related to generation of a reliable reference voltage.
    Type: Grant
    Filed: April 18, 2011
    Date of Patent: January 17, 2012
    Assignee: Seagate Technology LLC
    Inventors: Hongyue Liu, Yong Lu, Andrew Carter, Yiran Chen, Hai Li
  • Patent number: 8094481
    Abstract: A resistance variable memory apparatus (10) of the present invention comprises a resistance variable element (1) which is switched to a high-resistance state when a voltage exceeds a first voltage and is switched to a low-resistance state when the voltage exceeds a second voltage, a controller (4), a voltage restricting active element (2) which is connected in series with the resistance variable element (1); and a current restricting active element which is connected in series with the resistance variable element (1) via the voltage restricting active element (2), and the controller (4) is configured to control the current restricting active element (3) so that a product of a current and a first resistance value becomes a first voltage or larger and to control the voltage restricting active element (2) so that the voltage between electrodes becomes smaller than a second voltage when the element is switched to the high-resistance state, while the controller (4) is configured to control the current restricting
    Type: Grant
    Filed: March 12, 2008
    Date of Patent: January 10, 2012
    Assignee: Panasonic Corporation
    Inventors: Yoshikazu Katoh, Kazuhiko Shimakawa
  • Patent number: 8089799
    Abstract: The present invention provides a semiconductor device including a memory that has a memory cell array including a plurality of memory cells, a control circuit that controls the memory, and an antenna, where the memory cell array has a plurality of bit lines extending in a first direction and a plurality of word lines extending in a second direction different from the first direction, and each of the plurality of memory cells has an organic compound layer provided between the bit line and the word line. Data is written by applying optical or electric action to the organic compound layer.
    Type: Grant
    Filed: January 7, 2009
    Date of Patent: January 3, 2012
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Ryoji Nomura, Hiroko Abe, Yuji Iwaki, Shunpei Yamazaki
  • Patent number: 8077497
    Abstract: 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: Grant
    Filed: June 14, 2010
    Date of Patent: December 13, 2011
    Assignee: Sony Corporation
    Inventor: Kentaro Ogata
  • Patent number: 8068371
    Abstract: Methods and systems to dynamically control state-retention strengths of a plurality of memory cells during a write operation to a subset of the memory cells. Dynamic control may include weakening state-retention strengths of the plurality of memory cells during a write operation to a subset of the memory cells, while preserving state-retention abilities of remaining ones of the plurality of memory cells. Weakening may include adjusting one or more resistances between one or more power supplies and the plurality of memory cells. Dynamic control may be selectively performed on portions of each of the memory cells in response to an input data logic state. Dynamic control may reduce a write contention within the subset of memory cells without disabling state-retention abilities of remaining ones of the plurality of memory cells, and may improve write response times of the memory cells.
    Type: Grant
    Filed: December 31, 2008
    Date of Patent: November 29, 2011
    Assignee: Intel Corporation
    Inventors: Feroze A. Merchant, John Reginald Riley, Vinod Sannareddy
  • Patent number: 8064243
    Abstract: A method and apparatus for an integrated circuit with programmable memory cells which are arranged between a first and a second conductor for supplying first and second voltage is provided. A control circuit is arranged between the memory cells and the second conductor. The control circuit controls a change time during which at least one of the memory cells is supplied with a changing current from the second supply changing a state of the memory cell. The control circuit senses the state of the memory cell and stops the erasing current when the memory cell is in a changed state. Furthermore an embodiment refers to a data system with a programmable memory and a method of operating an integrated circuit. Another embodiment refers to a method of operating an integrated circuit.
    Type: Grant
    Filed: November 13, 2007
    Date of Patent: November 22, 2011
    Assignee: Qimonda AG
    Inventors: Milena Ivanov, Heinz Hoenigschmid, Stefan Dietrich
  • Patent number: 8059446
    Abstract: An integrated circuit with memory having a current limiting switch includes a memory cell having a programmable resistivity layer and a writing line. A switch is arranged between the resistivity layer and the writing line. The switch includes a control input connected to a select line. The switch is configured to limit a current through the resistivity layer for a write operation.
    Type: Grant
    Filed: September 8, 2008
    Date of Patent: November 15, 2011
    Assignee: Qimonda AG
    Inventor: Ralf Symanczyk
  • Patent number: 8059449
    Abstract: Memory devices are described herein along with method for operating the memory device. A memory cell as described herein includes a first electrode and a second electrode. The memory cell also comprises phase change material having first and second active regions arranged in series along an inter-electrode current path between the first and second electrode.
    Type: Grant
    Filed: March 4, 2010
    Date of Patent: November 15, 2011
    Assignee: Macronix International Co., Ltd.
    Inventors: Yen-Hao Shih, Chieh-Fang Chen, Hsiang-Lan Lung
  • Patent number: 8054706
    Abstract: A method and apparatus for protecting an electrical device using a non-volatile memory cell, such as an STRAM or RRAM memory cell. In some embodiments, a memory element is connected in parallel with a sensor element, where the memory element is configured to be repetitively reprogrammable between a high resistance state and a low resistance state. The memory element is programmed to the low resistance state when the sensor element is in a non-operational state and reprogrammed to the high resistance state when the sensor element is in an operational state.
    Type: Grant
    Filed: March 19, 2009
    Date of Patent: November 8, 2011
    Assignee: Seagate Technology LLC
    Inventors: Phillip Mark Goldman, Muralikrishnan Balakrishnan
  • Patent number: 8045359
    Abstract: Disclosed is a switching element including: an insulative substrate; a first electrode and a second electrode provided to the insulative substrate; an interelectrode gap between the first electrode and the second electrode, comprising a gap of a nanometer order which causes switching phenomenon of resistance by applying a predetermined voltage between the first electrode and the second electrode; and a sealing member to seal the interelectrode gap such that the gap is retained.
    Type: Grant
    Filed: August 20, 2008
    Date of Patent: October 25, 2011
    Assignees: Funai Electric Advanced Applied Technology Research Institute Inc., Funai Electric Co., Ltd.
    Inventors: Shigeo Furuta, Tsuyoshi Takahashi, Masatoshi Ono
  • Patent number: 8045370
    Abstract: A magnetic tunnel junction memory apparatus and self-reference read and write assist schemes are described. One method of self-reference reading a magnetic tunnel junction memory unit includes applying a first read current through a magnetic tunnel junction data cell to form a first bit line read voltage, then applying a first magnetic field through the magnetic tunnel junction data cell forming a magnetic field modified magnetic tunnel junction data cell, and then applying a second read current thorough the magnetic field modified magnetic tunnel junction data cell to form a second bit line read voltage. The first read current being less than the second read current. Then comparing the first bit line read voltage with the second bit line read voltage to determine whether the magnetic tunnel junction data cell was in a high resistance state or a low resistance state. Methods of applying a magnetic field to the MTJ and then writing the desired resistance state are also disclosed.
    Type: Grant
    Filed: August 27, 2010
    Date of Patent: October 25, 2011
    Assignee: Seagate Technology LLC
    Inventors: Wenzhong Zhu, Yiran Chen, Dimitar V. Dimitrov, Xiaobin Wang
  • Patent number: 8040714
    Abstract: A multilevel nonvolatile memory device using a resistance material is provided. The multilevel nonvolatile memory device includes at least one multilevel memory cell and a read circuit. The at least one multilevel memory cell has a level of resistance that varies according to data stored therein. The read circuit first reads first bit data from the multilevel memory cell by providing a first read bias to the multilevel memory cell and secondarily reads second bit data from the multilevel memory cell by providing a second read bias to the multilevel memory cell. The second read bias varies according to a result of the first reading.
    Type: Grant
    Filed: April 15, 2009
    Date of Patent: October 18, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Byung-Gil Choi, Du-Eung Kim
  • Patent number: 8040713
    Abstract: Various embodiments of the present invention are generally directed to a method and apparatus for providing different bit set modes for a resistive sense memory (RSM) array, such as a spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM) array. In accordance with some embodiments, a group of RSM cells in a non-volatile semiconductor memory array is identified for application of a bit set operation. A bit set value is selected from a plurality of bit set values each separately writable to the RSM cells to place said cells in a selected resistive state. The selected bit set value is thereafter written to at least a portion of the RSM cells in the identified group.
    Type: Grant
    Filed: January 13, 2009
    Date of Patent: October 18, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yiran Chen, Daniel S. Reed, Yong Lu, Harry Hongyue Liu, Hai Li, Rod V. Bowman
  • Patent number: 8036019
    Abstract: The present disclosure includes resistive memory devices and systems having resistive memory cells, as well as methods for operating the resistive memory cells. One memory device embodiment includes at least one resistive memory element, a programming circuit, and a sensing circuit. For example, the programming circuit can include a switch configured to select one of N programming currents for programming the at least one resistive memory element, where each of the N programming currents has a unique combination of current direction and magnitude, with N corresponding to the number of resistance states of the at least one memory element. In one or more embodiments, the sensing circuit can be arranged for sensing of the N resistance states.
    Type: Grant
    Filed: November 15, 2010
    Date of Patent: October 11, 2011
    Assignee: Micron Technology, Inc
    Inventors: Yantao Ma, Jun Liu
  • Publication number: 20110222330
    Abstract: A nonvolatile memory device comprises a one-time-programmable (OTP) lock bit register. The nonvolatile memory device comprises a variable-resistance memory cell array comprising an OTP block that store data and a register that stores OTP lock state information indicating whether the data is changeable. The register comprises a variable memory cell. An initial value of the OTP lock state information is set to a program protection state.
    Type: Application
    Filed: February 23, 2011
    Publication date: September 15, 2011
    Applicant: SAMSUNG ELECTRONICS CO., LTD.
    Inventors: Yong-Jun LEE, Kwang Jin LEE, Joon Min PARK, Huik Won SEO
  • Patent number: 8018760
    Abstract: A resistance variable element of the present invention and a resistance variable memory apparatus using the resistance variable element are a resistance variable element (10) including a first electrode, a second electrode, and a resistance variable layer (3) provided between the first electrode (2) and the second electrode (4) to be electrically connected to the first electrode (2) and the second electrode (4), wherein the resistance variable layer (3) contains a material having a spinel structure represented by a chemical formula of (ZnxFe1-x)Fe2O4, and the resistance variable element (10) has a feature that an electrical resistance between the first electrode (2) and the second electrode (4) increases by applying a first voltage pulse to between the first electrode (2) and the second electrode (4), and the electrical resistance between the first electrode (2) and the second electrode (4) decreases by applying a second voltage pulse whose polarity is the same as the first voltage pulse to between the first
    Type: Grant
    Filed: December 20, 2007
    Date of Patent: September 13, 2011
    Assignee: Panasonic Corporation
    Inventors: Shunsaku Muraoka, Koichi Osano, Satoru Fujii
  • Patent number: 8018761
    Abstract: A resistance variable element (10), a resistance variable memory apparatus, and a resistance variable apparatus, comprise a first electrode (2), a second electrode (4), and a resistance variable layer (3) which is disposed between the first electrode (2) and the second electrode (4) and is electrically connected to the first electrode (2) and to the second electrode (4), wherein the resistance variable layer (3) contains a material having a spinel structure which is expressed as a chemical formula of (NixFe1-x) Fe2O4, X being not smaller than 0.35 and not larger than 0.
    Type: Grant
    Filed: December 20, 2007
    Date of Patent: September 13, 2011
    Assignee: Panasonic Corporation
    Inventors: Shunsaku Muraoka, Koichi Osano, Satoru Fujii
  • Patent number: 8014185
    Abstract: A nonvolatile memory cell including at least two two-terminal non-linear steering elements arranged in series, and a resistivity switching storage element arranged in series with the at least two two-terminal non-linear steering elements. A memory array, comprising a plurality of the nonvolatile memory cells is also described. A method of forming a nonvolatile memory cell is also described.
    Type: Grant
    Filed: July 9, 2008
    Date of Patent: September 6, 2011
    Assignee: SanDisk 3D LLC
    Inventor: Roy E. Scheuerlein
  • Patent number: 8009458
    Abstract: Apparatus and associated method for asymmetric write current compensation for resistive sense memory (RSM) cells, such as but not limited to spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM) cells. In accordance with some embodiments, an RSM cell includes an RSM element coupled to a switching device. The switching device has a plurality of terminals. A control circuit compensates for asymmetric write characteristics of the RSM cell by limiting a range of voltage differentials across the terminals so as to be equal to or less than a magnitude of a source voltage applied to the switching device, thereby providing bi-directional write currents of substantially equal magnitude through the RSM element.
    Type: Grant
    Filed: January 27, 2011
    Date of Patent: August 30, 2011
    Assignee: Seagate Technology LLC
    Inventors: Yong Lu, Harry Hongyue Liu
  • Patent number: 8009457
    Abstract: Apparatus and method for write current compensation in a non-volatile memory cell, such as but not limited to spin-torque transfer random access memory (STRAM) or resistive random access memory (RRAM). In accordance with some embodiments, a non-volatile memory cell has a resistive sense element (RSE) coupled to a switching device, the RSE having a hard programming direction and an easy programming direction opposite the hard programming direction. A voltage boosting circuit includes a capacitor which adds charge to a nominal non-zero voltage supplied by a voltage source to a node to generate a temporarily boosted voltage. The boosted voltage is applied to the switching device when the RSE is programmed in the hard programming direction.
    Type: Grant
    Filed: December 14, 2010
    Date of Patent: August 30, 2011
    Assignee: Seagate Technology LLC
    Inventors: Hai Li, Yiran Chen, Harry Hongyue Liu, Henry Huang, Ran Wang
  • Patent number: 8004875
    Abstract: A data storage device and associated method for providing current magnitude compensation for memory cells in a data storage array. In accordance with some embodiments, unit cells are connected between spaced apart first and second control lines of common length. An equalization circuit is configured to respectively apply a common current magnitude through each of the unit cells by adjusting a voltage applied to the cells in relation to a location of each of the cells along the first and second control lines.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: August 23, 2011
    Assignee: Seagate Technology LLC
    Inventors: Markus Jan Peter Siegert, Michael Xuefei Tang, Andrew John Carter, Alan Xuguang Wang
  • Patent number: 8000127
    Abstract: A method of resetting a resistive change memory element is disclosed. The method comprises performing a series of programming operations—for example, a programming pulse of a predetermined voltage level and pulse width—on a resistive change memory element in order to incrementally increase the resistance of the memory element above some predefined threshold. Prior to each programming operation, the resistive state of the memory element is measured and used to determine the parameters used in that programming operation. If this measured resistance value is above a first threshold value, the memory element is determined to already be in a reset state and no further programming operation is performed. If this measured resistance value is below a second threshold value, this second threshold value being less than the first threshold value, a first set of programming parameters are used within the programming operation.
    Type: Grant
    Filed: November 13, 2009
    Date of Patent: August 16, 2011
    Assignee: Nantero, Inc.
    Inventors: Darlene Hamilton, Rinn Cleavelin
  • Patent number: 8000155
    Abstract: The present invention provides a method for writing data to a non-volatile memory device having first wirings and second wirings intersecting one another and memory cells arranged at each intersection therebetween, each of the memory cells having a variable resistive element and a rectifying element connected in series. According to the method, the second wirings are charged to a certain voltage not less than a rectifying-element threshold value, prior to a rise in a selected first wiring. Then, a selected first wiring is charged to a voltage required for writing or erasing, after which a selected second wiring is discharged.
    Type: Grant
    Filed: January 13, 2011
    Date of Patent: August 16, 2011
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Toshiaki Edahiro, Kazushige Kanda, Naoya Tokiwa, Takuya Futatsuyama, Koji Hosono, Shigeo Ohshima
  • Patent number: 7995368
    Abstract: Embodiments of the present invention disclose a memory architecture for optimizing memory performance and size. Memory optimization is realized by configuring the memory to a particular logic state; that is, restricting memory data storage to either logic “0” or “1.” The opposite logic state, “1” or “0,” can be available through initialization and, therefore, may be presumed. Accordingly, the presumed, initialized logic state is available unless the configured logic state in memory changes the initialized data during memory access. Memory size reduction is realized by restricting physical memory to contain only cells that store data. Memory size can be further reduced by eliminating redundant data rows and columns. By reducing memory size, processing speed can be enhanced and power consumption reduced relative to conventional memory structures.
    Type: Grant
    Filed: February 20, 2008
    Date of Patent: August 9, 2011
    Assignee: Toshiba America Research, Inc.
    Inventor: Bipul C. Paul
  • Patent number: 7978507
    Abstract: A non-volatile storage system includes a substrate, control circuitry on the substrate, a three dimensional memory array (above the substrate) that includes a plurality of memory cells with reversible resistance-switching elements, and circuits to SET and RESET the resistance-switching elements. The circuits that RESET the resistance-switching elements provide a pulse to the memory cells that is large enough in magnitude to SET and RESET the memory cells, and long enough to potentially RESET the memory cell but not long enough to SET the memory cells.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: July 12, 2011
    Assignee: SanDisk 3D, LLC
    Inventor: Roy E. Scheuerlein
  • Patent number: 7974115
    Abstract: A switching device disposed in a substrate is turned on and a program current is applied to a fuse electrically connected to a switching device, thereby cutting the fuse. The fuse includes a first electrode electrically connected to the switching device, a second electrode spaced apart from the first electrode, and a chalcogenide pattern disposed between the first and second electrodes.
    Type: Grant
    Filed: December 15, 2009
    Date of Patent: July 5, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chang-Wook Jeong, Jun-Hyok Kong, Hyung-Rok Oh
  • Patent number: 7974116
    Abstract: A variable resistance memory device includes a variable resistance memory cell array including a plurality of variable resistance memory cells; a plurality of global word lines configured to drive the variable resistance memory cell array; and a plurality of local word line decoders. Each of the plurality of local word line decoders includes a first transistor having a gate connected to the global word line. A voltage greater than an operation voltage of one or more of the plurality of local word line decoders is applied to a selected one of the plurality of global word lines.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: July 5, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Byung-gil Choi, Kwang-ho Kim
  • Publication number: 20110149631
    Abstract: The embodiments described herein are directed to a memory device with multi-level, write-once memory cells. In one embodiment, a memory device has a memory array comprising a plurality of multi-level write-once memory cells, wherein each memory cell is programmable to one of a plurality of resistivity levels. The memory device also contains circuitry configured to select a group of memory cells from the memory array, and read a set of flag bits associated with the group of memory cells. The set of flag bits indicate a number of times the group of memory cells has been written to. The circuitry is also configured to select a threshold read level appropriate for the number of times the group of memory cells has been written to, and for each memory cell in the group, read the memory cell as an unprogrammed single-bit memory cell or as a programmed single-bit memory cell based on the selected threshold read level.
    Type: Application
    Filed: December 21, 2009
    Publication date: June 23, 2011
    Inventors: Roy E. Scheuerlein, Luca Fasoli
  • Patent number: 7965539
    Abstract: A nonvolatile memory element (101) of the present invention includes a resistance variable layer (112) which intervenes between a first electrode (111) and a second electrode (113) and is configured to include at least an oxide of a metal element of VI group, V group or VI group, and when an electric pulse of a specific voltage is applied between the first voltage (111) and the second voltage (113), the resistance variable layer is turned to have a first high-resistance state or a second high-resistance state in which its resistance value is a high-resistance value RH, or a low-resistance state in which its resistance value is a low-resistance value RL.
    Type: Grant
    Filed: September 25, 2008
    Date of Patent: June 21, 2011
    Assignee: Panasonic Corporation
    Inventors: Koichi Osano, Shunsaku Muraoka, Satoru Fujii, Kazuhiko Shimakawa
  • Patent number: 7961509
    Abstract: 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. A magnetic field is applied through the free magnetic layer the 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 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 destabilizing magnetic field to the MTJ and then writing the desired resistance state are also disclosed.
    Type: Grant
    Filed: October 13, 2010
    Date of Patent: June 14, 2011
    Assignee: Seagate Technology LLC
    Inventors: Wenzhong Zhu, Yiran Chen, Xiaobin Wang, Zheng Gao, Haiwen Xi, Dimitar V. Dimitrov
  • Patent number: 7961494
    Abstract: A very dense cross-point memory array of multi-level read/write two-terminal memory cells, and methods for its programming, are described. Multiple states are achieved using two or more films that each have bi-stable resistivity states, rather than “tuning” the resistance of a single resistive element. An exemplary memory cell includes a vertical pillar diode in series with two different bi-stable resistance films. Each bi-stable resistance film has both a high resistance and low resistance state that can be switched with appropriate application of a suitable bias voltage and current. Such a cross-point array is adaptable for two-dimensional rewritable memory arrays, and also particularly well-suited for three-dimensional rewritable (3D R/W) memory arrays.
    Type: Grant
    Filed: September 30, 2008
    Date of Patent: June 14, 2011
    Assignee: SanDisk 3D LLC
    Inventor: Roy E. Scheuerlein
  • Patent number: 7961540
    Abstract: A dynamically-operating restoration circuit is used to apply a voltage or current restore pulse signal to thyristor-based memory cells and therein restore data in the cell using the internal positive feedback loop of the thyristor. In one example implementation, the internal positive feedback loop in the thyristor is used to restore the conducting state of a device after the thyristor current drops below the holding current. A pulse and/or periodic waveform are defined and applied to ensure that the thyristor is not released from its conducting state. The time average of the periodic restore current in the thyristor may be lower than the holding current threshold. While not necessarily limited to memory cells that are thyristor-based, various embodiments of the invention have been found to be the particularly useful for high-speed, low-power memory cells in which a thin capacitively-coupled thyristor is used to provide a bi-stable storage element.
    Type: Grant
    Filed: July 29, 2008
    Date of Patent: June 14, 2011
    Assignee: T-RAM Semiconductor, Inc.
    Inventors: Farid Nemati, Hyun-Jin Cho, Robert Homan Igehy
  • Patent number: 7961507
    Abstract: Some embodiments include apparatus and methods having a memory element configured to store information and an access component configured to allow conduction of current through the memory element when a first voltage difference in a first direction across the memory element and the access component exceeds a first voltage value and to prevent conduction of current through the memory element when a second voltage difference in a second direction across the memory element and the access component exceeds a second voltage value, wherein the access component includes a material excluding silicon.
    Type: Grant
    Filed: March 11, 2008
    Date of Patent: June 14, 2011
    Assignee: Micron Technology, Inc.
    Inventors: Jun Liu, Michael P. Violette
  • Patent number: 7952914
    Abstract: An integrated circuit memory device may include an integrated circuit substrate, and a multi-bit memory cell on the integrated circuit substrate. The multi-bit memory cell may be configured to store a first bit of data by changing a first characteristic of the multi-bit memory cell and to store a second bit of data by changing a second characteristic of the multi-bit memory cell. Moreover, the first and second characteristics may be different. Related methods are also discussed.
    Type: Grant
    Filed: May 17, 2007
    Date of Patent: May 31, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: In-Gyu Baek, Jang-Eun Lee, Se-Chung Oh, Kyung-Tae Nam, Jun-Ho Jeong
  • Patent number: 7948789
    Abstract: A resistance variable element comprises a first electrode (2), a second electrode (4), and a resistance variable layer (3) which is disposed between the first electrode and the second electrode, and electrically connected to the first electrode and the second electrode, wherein the resistance variable layer comprises material including TaOX (1.6?X?2.2), an electric resistance between the first electrode and the second electrode is lowered by application of a first voltage pulse having a first voltage between the first electrode and the second electrode, and the electric resistance between the first electrode and the second electrode is increased by application of a second voltage pulse having a second voltage of the same polarity as the first voltage, between the first electrode and the second electrode.
    Type: Grant
    Filed: March 27, 2008
    Date of Patent: May 24, 2011
    Assignee: Panasonic Corporation
    Inventors: Shunsaku Muraoka, Koichi Osano, Satoru Fujii
  • Patent number: 7940547
    Abstract: Example embodiments provide a method for programming a resistive memory device that includes a resistance conversion layer. The method may include applying multiple pulses to the resistance conversion layer. The multiple pulses may include at least two pulses, where a magnitude of each pulse of the at least two pulses is the same. A first pulse of the at least two pulses may be applied on one side of the resistance conversion layer and a second pulse of the at least two pulses may be applied on the other side of the resistance conversion layer. The applying step may be performed during a set programming operation or a reset programming operation. A resistive memory device for programming a resistance conversion layer may include a first and second electrode, a lower structure, and the resistance conversion layer coupled between the first and second electrodes.
    Type: Grant
    Filed: February 13, 2009
    Date of Patent: May 10, 2011
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Seung-hoon Lee, Yoon-dong Park, Young-soo Park, Myung-jae Lee
  • Patent number: 7940548
    Abstract: A resistive sense memory apparatus includes a first semiconductor transistor having a first contact electrically connected to a first source line and a second contact electrically connected to a first resistive sense memory element and a second semiconductor transistor having a first contact electrically connected to a second source line and a second contact electrically connected to a second resistive sense memory element. A bit line is electrically connected to the first resistive sense memory element and the second resistive sense memory element.
    Type: Grant
    Filed: July 13, 2009
    Date of Patent: May 10, 2011
    Assignee: Seagate Technology LLC
    Inventors: Xuguang Wang, Hai Li, Hongyue Liu
  • Patent number: 7936588
    Abstract: The present disclosure relates to memory arrays with read reference voltage cells. In particular the present disclosure relates to variable resistive memory cell apparatus and arrays that include a high resistance state reference memory cell and a low resistance state reference memory cell that provides a reliable average reference voltage on chip to compare to a read voltage of a selected memory cell and determine if the selected memory cell is in the high resistance state or low resistance state. These memory arrays are particularly suitable for use with spin-transfer torque memory cells and resolves many systematic issues related to generation of a reliable reference voltage.
    Type: Grant
    Filed: May 28, 2010
    Date of Patent: May 3, 2011
    Assignee: Seagate Technology LLC
    Inventors: Hongyue Liu, Yong Lu, Andrew Carter, Yiran Chen, Hai Li
  • Patent number: 7932101
    Abstract: A memory device with improved heat transfer characteristics. The device first includes a dielectric material layer; first and second electrodes, vertically separated and having mutually opposed contact surfaces. A phase change memory element is encased within the dielectric material layer, including a phase-change layer positioned between and in electrical contact with the electrodes, wherein the lateral extent of the phase change layer is less than the lateral extent of the electrodes. An isolation material is positioned between the phase change layer and the dielectric layer, wherein the thermal conductivity of the isolation material is lower than the thermal conductivity of the dielectric material.
    Type: Grant
    Filed: March 18, 2008
    Date of Patent: April 26, 2011
    Assignee: Macronix International Co., Ltd.
    Inventor: Hsiang-Lan Lung
  • Patent number: 7932506
    Abstract: Memory devices are described along with methods for manufacturing. A memory device as described herein includes a plurality of memory cells. Each memory cell in the plurality of memory cells comprises a diode comprising doped semiconductor material and a dielectric spacer on the diode and defining an opening, the dielectric spacer having sides self-aligned with sides of the diode. Each memory cell further comprises a memory element on the dielectric spacer and including a portion within the opening contacting a top surface of the diode.
    Type: Grant
    Filed: July 22, 2008
    Date of Patent: April 26, 2011
    Assignees: Macronix International Co., Ltd., International Business Machines Corporation
    Inventors: Hsiang-Lan Lung, Chung Hon Lam
  • Patent number: 7929331
    Abstract: A microelectronic programmable structure and methods of forming and programming the structure are disclosed. The programmable structure generally includes an ion conductor and a plurality of electrodes. Electrical properties of the structure may be altered by applying a bias across the electrodes, and thus information may be stored using the structure.
    Type: Grant
    Filed: February 5, 2010
    Date of Patent: April 19, 2011
    Assignee: Axon Technologies Corporation
    Inventor: Michael N. Kozicki
  • Patent number: 7929335
    Abstract: A symmetrically resistive memory material (such as a phase change material) is described for use as a rectifying element for driving symmetric or asymmetric resistive memory elements in a crosspoint memory architecture. The crosspoint architecture has a plurality of electrodes and a plurality of crossbar elements, with each crossbar element being disposed between a first and a second electrode. The crossbar element is made of a symmetric resistive memory element used as a rectifier in series with a symmetric or asymmetric resistive memory element.
    Type: Grant
    Filed: June 11, 2007
    Date of Patent: April 19, 2011
    Assignee: International Business Machines Corporation
    Inventor: Kailash Gopalakrishnan