Resistive Patents (Class 365/46)
  • Patent number: 7742330
    Abstract: For example, one memory cell is configured using two memory cell transistors and one phase change element by disposing a plurality of diffusion layers in parallel to a bit-line, disposing gates between the diffusion layers so as to cross the bit-line, disposing bit-line contacts and source contacts alternately to the plurality of diffusion layers arranged in a bit-line direction for each diffusion layer, and providing a phase change element on the source contact. Also, the phase change element can be provided on the bit-line contact instead of the source contact. By this means, for example, increase in drivability of the memory cell transistors and reduction in area can be realized.
    Type: Grant
    Filed: May 19, 2005
    Date of Patent: June 22, 2010
    Assignee: Renesas Technology Corp.
    Inventors: Riichiro Takemura, Kenzo Kurotsuchi, Takayuki Kawahara
  • Patent number: 7729162
    Abstract: In accordance with some embodiments, a phase change memory may be formed in which the thermal conductivity in the region outside the programmed volume of phase change material is reduced. This may reduce the power consumption of the resulting phase change memory. The reduction in power consumption may be achieved by forming distinct layers of phase change material that have little or no mixing between them outside the programmed volume. For example, in one embodiment, a diffusion barrier layer may be maintained between the two distinct phase change layers. In another embodiment, a face centered cubic chalcogenide structure may be utilized.
    Type: Grant
    Filed: October 9, 2007
    Date of Patent: June 1, 2010
    Assignee: Ovonyx, Inc.
    Inventors: Charles H. Dennison, Stephen J. Hudgens
  • Patent number: 7729160
    Abstract: A phase-change random access memory includes a memory block including a plurality of memory columns corresponding to the same column address and using different input/output paths; a redundancy memory block including a plurality of redundancy memory columns using different input/output paths; and an input/output controller repairing at least one of the plurality of memory columns using at least one of the plurality of redundancy memory columns, and controlling the number of memory columns simultaneously repaired using redundancy memory columns in response to an input/output repair mode control signal.
    Type: Grant
    Filed: December 28, 2006
    Date of Patent: June 1, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Byung-Gil Choi, Du-Eung Kim, Woo-Yeong Cho, Hye-Jin Kim
  • Patent number: 7729158
    Abstract: 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: Grant
    Filed: June 11, 2007
    Date of Patent: June 1, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Haruki Toda, Koichi Kubo
  • Patent number: 7719875
    Abstract: 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: Grant
    Filed: June 12, 2007
    Date of Patent: May 18, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Haruki Toda, Koichi Kubo
  • Patent number: 7719886
    Abstract: An integrated circuit includes a first electrode and a second electrode. The integrated circuit includes a first resistivity changing material between the first electrode and the second electrode and a second resistivity changing material between the first electrode and the second electrode. The first resistivity changing material and the second resistivity changing material have different crystallization speeds.
    Type: Grant
    Filed: May 3, 2007
    Date of Patent: May 18, 2010
    Assignee: Qimonda North America Corp.
    Inventors: Jan Boris Philipp, Thomas Happ
  • Patent number: 7706167
    Abstract: 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: Grant
    Filed: June 12, 2007
    Date of Patent: April 27, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Haruki Toda, Koichi Kubo
  • Patent number: 7701749
    Abstract: In a method of controlling resistance drift in a memory cell of a resistance-changeable material memory device, the resistance changeable material in the memory cell is treated so that a drift parameter for the memory cell is less than about 0.18, wherein a change in resistance of a memory cell over the time period is determined according to the relationship: Rdrift=Rinitial×t?; where Rdrift represents a final resistance of the memory cell following the time period, Rinitial represents the initial resistance of the memory cell following the programming operation, t represents the time period; and ? represents the drift parameter.
    Type: Grant
    Filed: March 28, 2008
    Date of Patent: April 20, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chang-Wook Jeong, Dae-Hwan Kang, Hyeong-Jun Kim, Seung-Pil Ko, Dong-Won Lim
  • Patent number: 7697316
    Abstract: 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: Grant
    Filed: December 7, 2006
    Date of Patent: April 13, 2010
    Assignee: Macronix International Co., Ltd.
    Inventors: Erh-Kun Lai, ChiaHua Ho, Kuang Yeu Hsieh
  • Patent number: 7672156
    Abstract: In a phase-change random access memory (PRAM) device, a write operation is performed by applying a set pulse to failed PRAM cells. The set pulse comprises a plurality of stages sequentially decreasing from a first current magnitude to a second current magnitude. The first current magnitude or the second current magnitude varies from one write loop to another.
    Type: Grant
    Filed: September 5, 2007
    Date of Patent: March 2, 2010
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Mu-hui Park, Beak-hyung Cho, Hyung-rok Oh
  • Patent number: 7652914
    Abstract: A memory includes a bit line and a phase change element. A first side of the phase change element is coupled to the bit line. The memory includes a first access device coupled to a second side of the phase change element and a second access device coupled to the second side of the phase change element. The memory includes a circuit for precharging the bit line and one of selecting only the first access device to program the phase change element to a first state and selecting both the first access device and the second access device to program the phase change element to a second state.
    Type: Grant
    Filed: January 9, 2007
    Date of Patent: January 26, 2010
    Assignees: Qimonda North America Corp., International Business Machines Corporation, Macronix International Co., Ltd.
    Inventors: Thomas Nirschl, Roger Cheek, Mark Lamorey, Ming-Hsiu Lee
  • Patent number: 7649242
    Abstract: A programmable resistive memory cell comprising a lower electrode, a programmable resistance layer, and an upper electrode, wherein a lower mask is arranged between the lower electrode and the programmable resistance layer and an upper mask is arranged between the programmable resistance layer and the upper electrode, and wherein the lower mask and the upper mask comprise current-inhibiting regions.
    Type: Grant
    Filed: June 14, 2006
    Date of Patent: January 19, 2010
    Assignee: Infineon Technologies AG
    Inventor: Klaus-Dieter Ufert
  • Patent number: 7639526
    Abstract: A method and apparatus for programming a phase change memory cell is disclosed. A phase change memory cell includes a memory element of a phase change material having a first state, in which the phase change material is crystalline and has a minimum resistance level, a second state in which the phase change material is amorphous and has a maximum resistance level, and a plurality of intermediate states with resistance levels there between. The method includes using programming pulses to program the phase change memory cell in either the set, reset, or one of the intermediate states. To program in the intermediate states, a programming pulse creates a crystalline percolation path having an average diameter through amorphous phase change material and a second programming pulse modifies the diameter of the crystalline percolation path to program the phase change memory cell to the proper current level.
    Type: Grant
    Filed: December 3, 2007
    Date of Patent: December 29, 2009
    Inventors: Fabio Pellizzer, Agostino Pirovano
  • Patent number: 7636251
    Abstract: A nonvolatile memory device may be operated in a multi-bit mode at a lower operating current and with higher integrated of the memory device. A first buried electrode may be used as a first bit line, a second buried electrode may be used as a second bit line, and/or a gate electrode may be used as a word line. First and second resistance layers may be programmed with 2-bit data and the 2-bit data may be read from the first and second resistance layers. More than 2-bit data may be programmed and read using more than 2 buried electrodes.
    Type: Grant
    Filed: July 12, 2007
    Date of Patent: December 22, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Yoon-dong Park, Kyoung-lee Cho, Jae-woong Hyun, Sung-jae Byun
  • Patent number: 7633795
    Abstract: A write control method for a magnetoresistive random access memory, which includes a memory cell having a recording layer with an axis of easy magnetization and an axis of hard magnetization. The write control method includes writing a datum into the memory cell. The writing of the datum includes applying a pulsative first magnetic field substantially parallel to the axis of easy magnetization of the recording layer and a pulsative second magnetic field substantially parallel to the axis of hard magnetization to the recording layer so as to cause a period of the pulsative first magnetic field and a period of the pulsative second magnetic field to overlap each other, and applying a pulsative third magnetic field having substantially the same direction as the pulsative first magnetic field to the recording layer at least once after applying the pulsative first magnetic field to the recording layer.
    Type: Grant
    Filed: September 20, 2006
    Date of Patent: December 15, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Naoharu Shimomura, Tatsuya Kishi, Ryousuke Takizawa
  • Patent number: 7619936
    Abstract: One embodiment of the present invention provides a system including a tester and a back end manufacturing system. The tester tests a resistive memory and obtains configuration data for the resistive memory. The back end manufacturing system prevents temperatures in back end processing from reducing data retention time of the configuration data in the resistive memory.
    Type: Grant
    Filed: November 16, 2006
    Date of Patent: November 17, 2009
    Assignee: Qimonda North America Corp.
    Inventors: Jan Boris Philipp, Thomas Happ
  • Patent number: 7613028
    Abstract: A switching element for reversible switching between an electrically insulating OFF state and an electrically conductive ON state, having two electrodes, namely a reactive electrode and an inert electrode, and also a solid electrolyte arranged between the two electrodes, which is characterized by the fact that the electrical conductivity of the solid electrolyte increases as the temperature thereof rises, but essentially no longer increases below a critical decomposition temperature of the solid electrolyte.
    Type: Grant
    Filed: May 18, 2005
    Date of Patent: November 3, 2009
    Assignee: Infineon Technologies AG
    Inventors: Cay-Uwe Pinnow, Klaus-Dieter Ufert
  • Patent number: 7613029
    Abstract: A phase change memory has a first electrode formed over a substrate, a patterned phase change material layer formed over the first electrode to contact the first electrode and including a conductive material, and a second electrode formed over the patterned phase change material layer to contact the patterned phase change material layer. Instead of heat generation, the conductive channel is used to adjust resistance while maintaining characteristics of non-volatile memories. Hence, the power consumption can be reduced. Due to no use of the phase change, the shortened lifetime of equipment for fabricating semiconductor memories, usually caused by a volume change during the phase change, can be reduced.
    Type: Grant
    Filed: December 19, 2006
    Date of Patent: November 3, 2009
    Assignee: Dongbu Electronics Co., Ltd.
    Inventor: Kwang Jean Kim
  • Patent number: 7606064
    Abstract: According to one embodiment, at least a portion of the phase change material including a first crystalline phase is converted to one of a second crystalline phase and an amorphous phase. The second crystalline phase transitions to the amorphous phase more easily than the first crystalline phase. For example the first crystalline phase may be a hexagonal closed packed structure and the first crystalline phase may be a face centered cubic structure.
    Type: Grant
    Filed: May 30, 2006
    Date of Patent: October 20, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Chang-Wook Jeong, Jun-Hyok Kong, Ji-Hye Yi, Beak-Hyung Cho
  • Patent number: 7579611
    Abstract: A memory cell for use in integrated circuits comprises a chalcogenide feature and a transition metal oxide feature. Both the chalcogenide feature and transition metal oxide feature each have at least two stable electrical resistance states. At least two bits of data can be concurrently stored in the memory cell by placing the chalcogenide feature into one of its stable electrical resistance states and by placing the transition metal oxide feature into one of its stable electrical resistance states.
    Type: Grant
    Filed: February 14, 2006
    Date of Patent: August 25, 2009
    Assignee: International Business Machines Corporation
    Inventors: Chung Hon Lam, Gerhard Ingmar Meijer, Alejandro Gabriel Schrott
  • Patent number: 7569909
    Abstract: Phase change memory devices and methods for manufacturing the same are provided. An exemplary embodiment of a phase change memory device comprises a substrate. A dielectric layer is formed over the substrate and a phase change material layer is embedded in the dielectric layer. A first conductive electrode is also embedded in the dielectric layer to penetrate the phase change material layer and extends perpendicular to a top surface of the dielectric layer.
    Type: Grant
    Filed: May 8, 2007
    Date of Patent: August 4, 2009
    Assignees: Industrial Technology Research Institute, Powerchip Semiconductor Corp., Nanya Technology Corporation, ProMOS Technologies Inc., Winbond Electronics Corp.
    Inventor: Chen-Ming Huang
  • Patent number: 7564731
    Abstract: A software refreshed memory device comprises a plurality of memory cells that must be periodically refreshed to avoid losing data. Preferably, the memory cells can avoid losing data even though the time interval between successive memory refresh operations is relatively long, as compared to the time interval between successive memory refresh operations in a conventional volatile memory device, such as a DRAM. A processor can perform periodic memory refresh operations by executing a set of memory refresh instructions implemented in software, rather than in hardware. Accordingly, the memory device can advantageously be simplified, because the need for memory refresh circuitry and for a unique refresh control signal are advantageously eliminated. Moreover, the processor executing the memory refresh instructions can typically perform more sophisticated algorithms, as compared to memory refresh circuitry implemented in hardware, for determining when to perform a memory refresh operation.
    Type: Grant
    Filed: May 30, 2007
    Date of Patent: July 21, 2009
    Assignee: Micron Technology, Inc.
    Inventor: Terry L. Gilton
  • Patent number: 7548449
    Abstract: A magnetic memory device and methods thereof are provided. The example magnetic memory device may include a transistor disposed within a given unit cell region and a magnetic tunneling junction (MTJ) element connected to the transistor, the MTJ element including an MTJ cell and first and second pad layers forming a magnetic field at first and second ends of the MTJ cell, the transistor including a drain connected to the first pad layer in the given unit cell region and a bit line, a source connected to the second pad layer in an adjacent unit cell region, and a gate connected to a word line corresponding to the given unit cell region.
    Type: Grant
    Filed: January 19, 2007
    Date of Patent: June 16, 2009
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Tae-Wan Kim, In-Jun Hwang, Young-Jin Cho, Kee-Won Kim
  • Patent number: 7515455
    Abstract: A memory device includes a first bit line in a first conducting layer and a second bit line parallel to the first bit line. The second bit line is in a second conducting layer. The memory device includes a MOS select transistor and a word line coupled to a gate of the MOS select transistor. The word line is at an angle with respect to the first bit line and the second bit line. The memory device includes a first resistive memory element coupled between a source of the MOS select transistor and the first bit line. The memory device includes a second resistive memory element coupled between a drain of the MOS select transistor and the second bit line.
    Type: Grant
    Filed: January 5, 2007
    Date of Patent: April 7, 2009
    Assignee: Qimonda North America Corp.
    Inventors: Thomas Nirshl, Thomas Happ
  • Patent number: 7508695
    Abstract: A data writing method for writing data sequentially in a cross-point memory cell array having a variable resistive element whose electric resistance is changed by application of an electric stress is provided. When data is sequentially written in memory cells in the same row or column, the writing order of the memory cells to be written is determined according to the length from an electric connection point to a selected memory cell to be written and the increase/decrease direction of the electric resistance of each selected memory cell changed by data writing, the electric connection point being between a write voltage applying circuit, which applies a data writing voltage to a same wiring of the selected word line or bit line connected to the selected memory cell, and the same wiring, and the data writing is executed based on the determined writing order.
    Type: Grant
    Filed: February 22, 2007
    Date of Patent: March 24, 2009
    Assignee: Sharp Kabushiki Kaisha
    Inventor: Yasuhiro Sugita
  • Patent number: 7474552
    Abstract: An integrated semiconductor memory device comprises: a receiver circuit for receiving a data signal, a receiver circuit for receiving a command signal, and a receiver circuit for receiving an address signal. A programmable storage unit comprises programmable elements. A current of the receiver circuits is controlled in dependence on a state of the programmable elements of the programmable storage unit. Depending on the application in which the integrated semiconductor memory device is used, the current of the receiver circuits is increased or decreased. By decreasing the current of the receiver circuits a dissipation loss of the integrated semiconductor memory device is reduced.
    Type: Grant
    Filed: March 8, 2006
    Date of Patent: January 6, 2009
    Assignee: Infineon Technologies AG
    Inventor: Simon Muff
  • Patent number: 7474555
    Abstract: A phase change memory cell includes a MOS select transistor having a gate coupled to a word line, and a source and drain region coupled between first and second bit lines, respectively. A first phase change element is coupled between the first bit line and the source region of the MOS select transistor. A method of reading a selected cell in the array is provided by evaluating a body effect impact of a state of the phase change element associated with the selected cell on a MOS select transistor.
    Type: Grant
    Filed: March 17, 2006
    Date of Patent: January 6, 2009
    Inventors: Thomas Nirschl, Thomas Happ
  • Patent number: 7468906
    Abstract: A word line driver and decoder for use in a magnetic memory includes a main word line driver and a sub word line driver that cooperate to drive current on a selected one from a number of the magnetic memory's word lines. The main word line driver and sub word line driver employ pull up and pull down transistors that configured to drive current on the selected word line in either a read or write ‘0’ direction or a read or write ‘1’ direction in response to control signals that allow reliable magnetic memory operation. An address decoder selects and activates a multiplexer in the sub word line driver to coordinate the current drive. The main word line driver employs current mirrors, transistor switches, and logic control to prevent direct Vdd to Vss shorting in transitioning from ‘0’ and ‘1’, and read and write data storage operations.
    Type: Grant
    Filed: September 11, 2006
    Date of Patent: December 23, 2008
    Assignee: Northern Lights Semiconductor Corp.
    Inventors: Chien-Teh Kuo, James Chyi Lai
  • Patent number: 7463506
    Abstract: A first variable resistor (5) is connected between a first terminal (7) and a third terminal (9) and increases/reduces its resistance value in accordance with the polarity of a pulse voltage applied between the first terminal (7) and the third terminal (9). A second variable resistor (6) is connected between the third terminal (9) and a second terminal (8) and increases/reduces its resistance value in accordance with the polarity of a pulse voltage applied between the third terminal (9) and the second terminal (8). Given pulse voltages are applied between the first terminal (7) and the third terminal (9) and between the third terminal (9) and the second terminal (8) to reversibly change the resistance values of the first and second variable resistors (5, 6), thereby recording one bit or multiple bits of information.
    Type: Grant
    Filed: October 22, 2004
    Date of Patent: December 9, 2008
    Assignee: Panasonic Corporation
    Inventors: Shunsaku Muraoka, Koichi Osano, Ken Takahashi, Masafumi Shimotashiro
  • Patent number: 7447056
    Abstract: A method for using a multi-use memory cell and memory array are disclosed. In one preferred embodiment, a memory cell is operable as a one-time programmable memory cell or a rewritable memory cell. The memory cell comprises a memory element comprising a semiconductor material configurable to one of at least three resistivity states, wherein a first resistivity state is used to represent a data state of the memory cell when the memory cell operates as a one-time programmable memory cell but not when the memory cell operates as a rewritable memory cell. A memory array with such memory cells is also disclosed. In another preferred embodiment, a memory cell is provided comprising a switchable resistance material, wherein the memory cell is operable in a first mode in which the memory cell is programmed with a forward bias and a second mode in which the memory cell is programmed with a reverse bias.
    Type: Grant
    Filed: July 31, 2006
    Date of Patent: November 4, 2008
    Assignee: SanDisk 3D LLC
    Inventors: Roy E. Scheuerlein, Tanmay Kumar
  • Patent number: 7440339
    Abstract: This invention relates to an MRAM array architecture which incorporates certain advantages from both cross-point and 1T-1MTJ architectures during reading operations. The fast read-time and higher signal to noise ratio of the 1T-1MTJ architecture and the higher packing density of the cross-point architecture are both exploited by using a single access transistor to control the reading of multiple stacked columns of MRAM cells each column being provided in a respective stacked memory layer.
    Type: Grant
    Filed: June 2, 2005
    Date of Patent: October 21, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Hasan Nejad, Mirmajid Seyyedy
  • Patent number: 7440303
    Abstract: A semiconductor memory device includes resistance memory elements that are coupled to selection transistors addressed by word lines and bit lines. The memory elements are read by read/write lines arranged parallel to the word lines. Two successive memory elements along a read/write line are coupled to selection transistors that are coupled to different word lines.
    Type: Grant
    Filed: March 14, 2007
    Date of Patent: October 21, 2008
    Assignee: Qimonda AG
    Inventor: Corvin Liaw
  • Publication number: 20080224178
    Abstract: A memory device includes a multi gate field effect transistor (MuGFET) having a fin with a contact area. A programmable memory element abuts the fin contact area.
    Type: Application
    Filed: March 16, 2007
    Publication date: September 18, 2008
    Applicants: INFINEON TECHNOLOGIES, QIMONDA AGGUSTAV
    Inventors: Christian Pacha, Tim Schonauer, Michael Kund
  • Patent number: 7423902
    Abstract: A storage device includes memory cells disposed in a matrix. The memory cells each include a storage element whose resistance changes from a higher state to a lower state when an electric signal of a first threshold level or higher is applied and whose resistance changes from the lower state to the higher state when an electric signal of a second threshold level or higher whose polarity is different from the polarity of the electric signal of the first threshold level or higher is applied, and a circuit element connected in series with the storage element. In a state in which an erasing voltage is applied to at least one memory cell on which erasing is currently being performed, after the lapse of a predetermined time from the application, an erasing voltage is applied to at least one memory cell on which erasing is to be next performed.
    Type: Grant
    Filed: May 25, 2006
    Date of Patent: September 9, 2008
    Assignee: Sony Corporation
    Inventors: Hironobu Mori, Hidenari Hachino, Nobumichi Okazaki
  • Patent number: 7423897
    Abstract: A method of operating a programmable resistance memory array. The method comprises writing to all of the programmable resistance elements within the same row of the memory array at substantially the same time. The programmable resistance elements preferably include phase-change materials such as chalcogenides.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: September 9, 2008
    Assignee: Ovonyx, Inc.
    Inventor: Guy C. Wicker
  • Patent number: 7397681
    Abstract: Phase-changeable random access memory (PRAM) devices include a plurality of rows and columns of PRAM memory cells therein and at least one local bit line electrically coupled to a column of the PRAM memory cells. First and second bit line selection circuits are provided to increase the rate at which the at least one local bit line can be accessed and driven with a bit line signal. These first and second bit line selection circuits are configured to electrically connect first and second ends of the at least one local bit line to a global bit line during an operation to read data from a selected one of the PRAM memory cells in the column.
    Type: Grant
    Filed: February 6, 2006
    Date of Patent: July 8, 2008
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Beak-hyung Cho, Du-eung Kim, Choong-keun Kwak, Hyung-rok Oh, Woo-yeong Cho
  • Patent number: 7391642
    Abstract: A method for programming a phase change memory cell is discussed. A phase change memory cell includes a memory element of a phase change material having a first state, in which the phase change material is crystalline and has a minimum resistance level, a second state in which the phase change material is amorphous and has a maximum resistance level, and a plurality of intermediate states, in which the phase change material includes both crystalline regions and amorphous regions and has intermediate resistance levels. According to the method, a plurality of programming pulses are provided to the phase change memory cell; programming energies respectively associated to the programming pulses are lower than a threshold energy which is required to bring the phase change material to the second state.
    Type: Grant
    Filed: January 25, 2005
    Date of Patent: June 24, 2008
    Assignee: Intel Corporation
    Inventors: George Gordon, Stephen Hudgens, Fabio Pellizzer, Agostino Pirovano
  • Patent number: 7354793
    Abstract: A method of forming a memory device, such as a PCRAM, including selecting a chalcogenide glass backbone material for a resistance variable memory function and devices formed using such a method.
    Type: Grant
    Filed: August 12, 2004
    Date of Patent: April 8, 2008
    Assignee: Micron Technology, Inc.
    Inventor: Kristy A. Campbell
  • Patent number: 7348209
    Abstract: Methods and apparatus for providing a resistance variable memory device with agglomeration prevention and thermal stability. According to one embodiment, a resistance variable memory device is provided having at least one tin-chalcogenide layer proximate at least one chalcogenide glass layer. The invention also relates to methods of forming such a memory device.
    Type: Grant
    Filed: August 29, 2006
    Date of Patent: March 25, 2008
    Assignee: Micron Technology, Inc.
    Inventor: Kristy A. Campbell
  • Patent number: 7339811
    Abstract: This invention relates to an MRAM array architecture which incorporates certain advantages from both cross-point and 1T-1MTJ architectures during reading operations. The fast read-time and higher signal to noise ratio of the 1T-1MTJ architecture and the higher packing density of the cross-point architecture are both exploited by using a single access transistor to control the reading of multiple stacked columns of MRAM cells each column being provided in a respective stacked memory layer.
    Type: Grant
    Filed: June 2, 2005
    Date of Patent: March 4, 2008
    Assignee: Micron Technology, Inc.
    Inventors: Hasan Nejad, Mirmajid Seyyedy
  • Patent number: 7335907
    Abstract: A phase change memory device is provided which is constituted by memory cells using memory elements and select transistors and having high heat resistance to be capable of an operation at 140 degrees or higher. As a device configuration, a recording layer of which, of Zn—Ge—Te, content of Zn, Cd or the like is 20 atom percent or more, content of at least one element selected from the group consisting of Ge and Sb is less than 40 atom percent, and content of Te is 40 atom percent or more is used. It is thereby possible to implement the memory device usable for an application which may be performed at a high temperature such as an in-vehicle use.
    Type: Grant
    Filed: March 3, 2004
    Date of Patent: February 26, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Motoyasu Terao, Norikatsu Takaura, Kenzo Kurotsuchi, Hideyuki Matsuoka, Tsuyoshi Yamauchi
  • Patent number: 7286378
    Abstract: A memory device having memory cells in which a single access transistor controls the grounding of at least four storage elements, such as resistive storage elements, for purposes of reading the respective logical states of the storage elements. Unique sensing techniques are provided to sense the states of the storage elements. The logical states of the storage elements are decoupled from one another and are read independently.
    Type: Grant
    Filed: June 23, 2004
    Date of Patent: October 23, 2007
    Assignee: Micron Technology, Inc.
    Inventor: Hagop A. Nazarian
  • Patent number: 7209378
    Abstract: A memory array architecture incorporates certain advantages from both cross-point and 1T-1Cell architectures during reading operations. The fast read-time and higher signal to noise ratio of the 1T-1Cell architecture and the higher packing density of the cross-point architecture are both exploited by using a single access transistor to control the reading of multiple stacked columns of memory cells, each column being provided in a respective stacked memory layer.
    Type: Grant
    Filed: August 25, 2004
    Date of Patent: April 24, 2007
    Assignee: Micron Technology, Inc.
    Inventors: Hasan Nejad, Mirmajid Seyyedy
  • Patent number: 7184297
    Abstract: A semiconductor memory includes: a first node and a second node; a first MIS transistor, having first conductive carrier flows, including a source electrode connected to a first power supply, a drain electrode connected to the second node, and a gate electrode connected to the first node; a second MIS transistor, having second conductive carrier flows, including a source electrode connected to a second power supply, a drain electrode connected to the second node, and a gate electrode connected to the first node; and a resistance change element connected between the first node and the second node and having a variable resistance due to the direction in which a voltage is applied, wherein information is written in the resistance change element by applying a voltage between the first and the second node, and stored information is read out by applying a low or high input voltage to the first node and reading out a voltage difference in the second node.
    Type: Grant
    Filed: June 24, 2005
    Date of Patent: February 27, 2007
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Shinichi Yasuda, Keiko Abe
  • Patent number: 7149100
    Abstract: A memory array architecture suitable for variable resistance memory that mitigates sneak path and associated problems by limiting the number of memory cells associated with an addressed cell to a known number having a sneak path resistance that can be calculated and taken into consideration when sensing the addressed memory cell. Blocks of memory cells are associated with access transistors, which separate the memory cells connected thereto into one half (½) sections of cell blocks. The access transistors can be associated with n memory cells, where n is an even number of at least 2; there may or may not be an equal number of cells on either side of the transistor. The memory array has memory cells, which are grouped into 1T-2nCell blocks.
    Type: Grant
    Filed: December 22, 2005
    Date of Patent: December 12, 2006
    Assignee: Micron Technology, Inc.
    Inventor: Hagop A. Nazarian
  • Patent number: 7123498
    Abstract: MRAM has read word lines WLR and write word line WLW extending in the y direction, write/read bit line BLW/R and write bit line BLW extending in the x direction, and the memory cells MC disposed at the points of the intersection of these lines. The memory MC includes sub-cells SC1 and SC2. The sub-cell SC1 includes magneto resistive elements MTJ1 and MTJ2 and a selection transistor Tr1, and the sub-cell SC2 includes magneto resistive elements MTJ3 and MTJ4 and a selection transistor Tr2. The magneto resistive elements MTJ1 and MTJ2 are connected in parallel, and the magneto resistive elements MTJ3 and MTJ4 are also connected in parallel. Further, the sub-cells SC1 and SC2 are connected in series between the write/read bit line BLW/R and the ground.
    Type: Grant
    Filed: October 12, 2004
    Date of Patent: October 17, 2006
    Assignee: International Business Machines Corporation
    Inventors: Hisatada Miyatake, Kohki Noda, Toshio Sunaga, Hiroshi Umezaki, Hideo Asano, Koji Kitamura
  • Patent number: 7106618
    Abstract: A method of driving a non-volatile memory which comprises a plurality of memory cells arranged in a two dimensional array, each having a field-effect transistor (1) whose gate and substrate are connected and a variable resistor element (2) comprising a phase change material; in which a specific voltage is applied to a specific word line (WLi), bit line (BLj) and voltage supply section (VA) so that a voltage which is higher than a forward rise voltage of the pn junction between the source and substrate of the field-effect transistor (1) is applied between the specific word line (WLi) and bit line (BLj), and then the voltage applied to the word line (WLi) is rapidly or gradually returned to the initial voltage to change an applicable variable resistor element (2) into the high or low resistance state, whereby data is deleted or recorded, and data is read by turning on the field-effect transistor (1) and detecting the resistance value of the applicable variable resistor element (2).
    Type: Grant
    Filed: December 8, 2004
    Date of Patent: September 12, 2006
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Kiyoshi Morimoto
  • Patent number: 7064970
    Abstract: A memory array architecture suitable for variable resistance memory that mitigates sneak path and associated problems by limiting the number of memory cells associated with an addressed cell to a known number having a sneak path resistance that can be calculated and taken into consideration when sensing the addressed memory cell. Blocks of memory cells are associated with access transistors, which separate the memory cells connected thereto into one half (½) sections of cell blocks. The access transistors can be associated with n memory cells, where n is an even number of at least 2; there may or may not be an equal number of cells on either side of the transistor. The memory array has memory cells, which are grouped into 1T-2nCell blocks.
    Type: Grant
    Filed: November 4, 2003
    Date of Patent: June 20, 2006
    Assignee: Micron Technology, Inc.
    Inventor: Hagop A. Nazarian
  • Patent number: 7035141
    Abstract: The present memory structure includes thereof a first conductor, a second conductor, a resistive memory cell connected to the second conductor, a first diode connected to the resistive memory cell and the first conductor, and oriented in the forward direction from the resistive memory cell to the first conductor, and a second diode connected to the resistive memory cell and the first conductor, in parallel with the first diode, and oriented in the reverse direction from the resistive memory cell to the first conductor. The first and second diodes have different threshold voltages.
    Type: Grant
    Filed: November 17, 2004
    Date of Patent: April 25, 2006
    Inventors: Nicholas H. Tripsas, Colin S. Bill, Michael A. VanBuskirk, Matthew Buynoski, Tzu-Ning Fang, Wei Daisy Cai, Suzette Pangrle, Steven Avanzino
  • Patent number: 7023743
    Abstract: This invention relates to an array architecture which incorporates certain advantages from both cross-point and 1T-1MTJ architectures during reading operations. The fast read-time and higher signal to noise ratio of the 1T-1MTJ architecture and the higher packing density of the cross-point architecture are both exploited by using a single access transistor to control the reading of multiple stacked columns of cells each column being provided in a respective stacked memory layer.
    Type: Grant
    Filed: February 24, 2004
    Date of Patent: April 4, 2006
    Assignee: Micron Technology, Inc.
    Inventors: Hasan Nejad, Mirmajid Seyyedy