Diodes Patents (Class 365/175)
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Publication number: 20090116272Abstract: Provided are a non-volatile memory device and a cross-point memory array including the same which have a diode characteristic enabling the non-volatile memory device and the cross-point memory array including the same to operate in a simple structure, without requiring a switching device separately formed so as to embody a high density non-volatile memory device. The non-volatile memory device includes a first electrode; a diode-storage node formed on the first electrode; and a second electrode formed on the diode-storage node.Type: ApplicationFiled: July 7, 2008Publication date: May 7, 2009Inventors: Ki-hwan Kim, Young-soo Park, Bo-soo Kang, Myoung-jae Lee, Chang-bum Lee
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Publication number: 20090109726Abstract: A high-speed, low-power memory device comprises an array of non-linear conductors wherein the storage, address decoding, and output detection are all accomplished with diodes or other non-linear conductors. In various embodiments, the row and column resistors are switchable between a high resistance when connected to a row or column that is non-selected, and a low resistance when connected to the selected row and column.Type: ApplicationFiled: October 29, 2007Publication date: April 30, 2009Inventor: Daniel R. Shepard
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Patent number: 7525832Abstract: First electrode layer includes a plurality of first electrode lines (W1, W2) extending parallel to each other. State-variable layer lying on the first electrode layer includes a plurality of state-variable portions (60-11, 60-12, 60-21, 60-22) which exhibits a diode characteristic and a variable-resistance characteristic. Second electrode layer lying on the state-variable layer includes a plurality of second electrode lines (B1, B2) extending parallel to each other. The plurality of first electrode lines and the plurality of second electrode lines are crossing each other when seen in a layer-stacking direction with the state-variable layer interposed therebetween. State-variable portion (60-11) is provided at an intersection of the first electrode line (W1) and the second electrode line (B1) between the first electrode line and the second electrode line.Type: GrantFiled: April 21, 2006Date of Patent: April 28, 2009Assignee: Panasonic CorporationInventors: Shunsaku Muraoka, Koichi Osano, Satoru Mitani, Hiroshi Seki
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Patent number: 7522448Abstract: A passive element memory device is provided that includes memory cells comprised of a state change element in series with a steering element. Controlled pulse operations are used to perform resistance changes associated with set and reset operations in an array of memory cells. Selected memory cells in an array are switched to a target resistance state in one embodiment by applying a positive voltage pulse to selected first array lines while applying a negative voltage pulse to selected second array lines. An amplitude of voltage pulses can be increased while being applied to efficiently and safely switch the resistance of cells having different operating characteristics. The cells are subjected to reverse biases in embodiments to lower leakage currents and increase bandwidth. The amplitude and duration of voltage pulses are controlled, along with the current applied to selected memory cells in some embodiments.Type: GrantFiled: July 31, 2006Date of Patent: April 21, 2009Assignee: SanDisk 3D LLCInventors: Roy E. Scheuerlein, Tanmay Kumar
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Publication number: 20090097295Abstract: A nonvolatile semiconductor memory device can prevent memory characteristics from deteriorating due to IR drop on word or bit lines in a cross-point type memory cell array. The device comprises a word line selection circuit selecting a selected word line from word lines and applying selected and unselected word line voltages to the selected and unselected word lines, respectively, a bit line selection circuit selecting a selected bit line from bit lines and applying selected and unselected bit line voltages to the selected and unselected bit lines, respectively, and voltage control circuits preventing voltage fluctuation of at least either one of the word and bit lines, wherein at least either one of the word and bit lines are connected to the voltage control circuits at a voltage control point positioned at a farthest point from a drive point connected to the word line selection circuit or bit line selection circuit.Type: ApplicationFiled: November 1, 2006Publication date: April 16, 2009Inventor: Hidenori Morimoto
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Publication number: 20090080254Abstract: A memory integrated circuit has memory arrays that are vertically layered. These memory arrays include word lines and bit lines. Intersections between the word lines and the bit lines include a diode and a memory state storage element. The diode and the memory storage element are connected in between a word line and a bit line. The diode at the intersections includes a first diode node and a second diode node. Various aspects of the memory integrated circuit are electrically interconnected in various ways, such as corresponding word lines, corresponding first diode nodes, or corresponding second diode nodes of different memory arrays being electrically interconnected. Various aspects of the memory integrated circuit are isolated in various ways, such as word lines, first diode nodes, or second diode nodes of different memory arrays being isolated.Type: ApplicationFiled: December 2, 2008Publication date: March 26, 2009Applicant: Macronix International Co., Ltd.Inventors: Yi Ying Liao, Wen Jer Tsai, Chih Chieh Yeh
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Patent number: 7508050Abstract: A negative differential resistance (NDR) diode and a memory cell incorporating that NDR diode are provided. The NDR diode comprises a p-type germanium region in contact with an n-type germanium region and forming a germanium pn junction diode. A first gate electrode overlies the p-type germanium region, is electrically coupled to the n-type germanium region, and is configured for coupling to a first electrical potential. A second gate electrode overlies the n-type germanium region and is configured for coupling to a second electrical potential. A third electrode is electrically coupled to the p-type germanium region and may be coupled to the second gate electrode. A small SRAM cell uses two such NDR diodes with a single pass transistor.Type: GrantFiled: March 16, 2006Date of Patent: March 24, 2009Assignee: Advanced Micro Devices, Inc.Inventors: Gen Pei, Zoran Krivokapic
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Patent number: 7505324Abstract: A semiconductor memory device comprises a first to a fourth semiconductor layer of a first conductivity type which are formed in a fifth semiconductor layer of a second conductivity type in such a manner that they are isolated from one another, memory cells each of which includes a first MOS transistor formed on the first semiconductor layer, a second and a third MOS transistor which are formed on the second and third semiconductor layers, respectively, a first metal wiring layer which connects the gate of the first MOS transistor to the source or drain of at least one of the second and third MOS transistors, and a first contact plug which connects the fourth semiconductor layer to the first metal wiring layer. The first wiring layer is in the lowest layer of the metal wiring lines connected to the gate of the first MOS transistor.Type: GrantFiled: September 19, 2006Date of Patent: March 17, 2009Assignee: Kabushiki Kaisha ToshibaInventors: Akira Umezawa, Kazuhiko Kakizoe
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Publication number: 20090046501Abstract: A flash-RAM memory includes non-volatile random access memory (RAM) formed on a monolithic die and non-volatile page-mode memory formed on top of the non-volatile RAM, the non-volatile page-mode memory and the non-volatile RAM reside on the monolithic die.Type: ApplicationFiled: July 30, 2008Publication date: February 19, 2009Applicant: YADAV TECHNOLOGY, INC.Inventors: Rajiv Yadav RANJAN, Parviz KESHTBOD, Mahmud ASSAR
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Publication number: 20090046503Abstract: A memory cell for use in an integrated circuit comprises a read transistor and a gated diode. The read transistor has a source terminal. The gated diode has a gate terminal in signal communication with the read transistor. A variable source voltage acts on the source terminal of the read transistor when the memory cell is in operation. The variable source voltage is temporarily altered when the memory cell is read. For example, the source voltage may be reduced when the read transistor is implemented using an N-type transistor and increased when the read transistor is implemented using P-type transistor. This acts to impart the memory cell with faster read speed, higher read margin, and lower standby current.Type: ApplicationFiled: August 17, 2007Publication date: February 19, 2009Inventors: Wing Kin Luk, Robert Heath Dennard
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Patent number: 7483296Abstract: A memory device is proposed. The memory device includes a plurality of memory cells, wherein each memory cell includes a storage element and a selector for selecting the corresponding storage element during a reading operation or a programming operation. The selector includes a unipolar element and a bipolar element. The memory device further includes control means for prevalently enabling the unipolar element during the reading operation or the bipolar element during the programming operation.Type: GrantFiled: September 22, 2005Date of Patent: January 27, 2009Inventors: Ferdinando Bedeschi, Fabio Pellizzer, Augusto Benvenuti, Loris Vendrame, Paola Zuliani
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Patent number: 7474558Abstract: A gated diode nonvolatile memory cell with a charge storage structure includes a diode structure with an additional gate terminal. Example embodiments include the individual memory cell, an array of such memory cells, methods of operating the memory cell or array of memory cells, and methods of manufacturing the same.Type: GrantFiled: October 1, 2007Date of Patent: January 6, 2009Assignee: Macronix International Co., Ltd.Inventors: Yi Ying Liao, Wen Jer Tsai, Chih Chieh Yeh
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Patent number: 7470352Abstract: Sensor arrangement having row and column lines arranged in first and second directions, respectively, sensor arrays arranged in crossover regions of the row and column lines, a detector, and a decoding device. The sensor arrays have a coupling device for electrically coupling respective row and column lines, and a sensor element to influence electric current flow through the coupling device. The detector is electrically coupled to a respective end section of at least a portion of the row and column lines, and detects a respective accumulative current flow from the individual electrical current flows provided by the sensor arrays of the respective lines. The decoding device is coupled to the row and column lines, and evaluates at least a portion of the accumulative electric current flows fed to the decoding device via the row and column lines to determine at which of the sensor elements a sensor signal is present.Type: GrantFiled: April 16, 2004Date of Patent: December 30, 2008Assignee: Infineon Technologies AGInventors: Bjorn-Oliver Eversmann, Christian Paulus, Guido Stromberg, Roland Thewes
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Publication number: 20080316796Abstract: A method of making a nonvolatile memory device includes forming a first electrode, forming at least one nonvolatile memory cell including a diode and a metal oxide antifuse dielectric layer over the first electrode, and forming a second electrode over the at least one nonvolatile memory cell. In use, the diode acts as a read/write element of the nonvolatile memory cell by switching from a first resistivity state to a second resistivity state different from the first resistivity state in response to an applied bias.Type: ApplicationFiled: June 25, 2007Publication date: December 25, 2008Inventor: S. Brad Herner
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Publication number: 20080316809Abstract: A nonvolatile memory device includes at least one memory cell which comprises a diode and a metal oxide antifuse dielectric layer, and a first electrode and a second electrode electrically contacting the at least one memory cell. In use, the diode acts as a read/write element of the memory cell by switching from a first resistivity state to a second resistivity state different from the first resistivity state in response to an applied bias.Type: ApplicationFiled: June 25, 2007Publication date: December 25, 2008Inventor: S. Brad Herner
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Publication number: 20080316808Abstract: A nonvolatile memory device includes at least one nonvolatile memory cell which comprises a silicon, germanium or silicon-germanium diode which is doped with at least one of carbon or nitrogen in a concentration greater than an unavoidable impurity level concentration.Type: ApplicationFiled: June 25, 2007Publication date: December 25, 2008Inventors: S. Brad Herner, Mark H. Clark, Tanmay Kumar
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Patent number: 7466586Abstract: Diode-based capacitor memory uses relatively small capacitor, and uses a diode as an access device instead of MOS transistor, wherein the diode has four terminals, the first terminal is connected to a word line, the second terminal is connected to the first plate of capacitor which serves as a storage node, the third terminal is floating, the fourth terminal is connected to a bit line, wherein the capacitor is formed between the first plate and the second plate, and a plate line is connected to the second plate, during write the storage node is coupled or not, depending on the state of the diode by changing the plate line, during read the diode serves as a sense amplifier as well to detect the storage node voltage whether it is forward bias or not, in this manner the capacitor does not drive heavily loaded bit line directly, instead, it drives lightly loaded second terminal, and then the diode sends binary results to a data latch including a current mirror which repeats the amount of current that the memory cType: GrantFiled: January 10, 2006Date of Patent: December 16, 2008Inventor: Juhan Kim
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Publication number: 20080304308Abstract: One embodiment of the present invention includes a low-cost unipolar rewritable variable-resistance memory device, made of cross-point arrays of memory cells, vertically stacked on top of one another and compatible with a polycrystalline silicon diode.Type: ApplicationFiled: July 25, 2008Publication date: December 11, 2008Applicant: Hitachi Global Storage Technologies Netherlands B.V.Inventor: Barry Cushing STIPE
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Publication number: 20080298115Abstract: In the present resistive memory array, included are a substrate, a plurality of source regions in the substrate, and a conductor connecting the plurality of source regions, the conductor being positioned adjacent to the substrate to form, with the plurality of source regions, a common source. In one embodiment, the conductor is an elongated metal body of T-shaped cross-section. In another embodiment, the conductor is a plate-like metal body.Type: ApplicationFiled: November 13, 2007Publication date: December 4, 2008Inventor: Masao Taguchi
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Patent number: 7460395Abstract: A new memory cell can contain only a single thyristor. There is no need to include an access transistor in the cell. In one embodiment, the thyristor is a thin capacitively coupled thyristor. The new memory cell can be connected to word, bit, and control lines in several ways to form different memory arrays. Timing and voltage levels of word, bit and control lines are disclosed.Type: GrantFiled: June 22, 2005Date of Patent: December 2, 2008Assignee: T-RAM Semiconductor, Inc.Inventors: Hyun-Jin Cho, Farid Nemati
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Patent number: 7453755Abstract: An integrated circuit and associated method of programming are provided. Such integrated circuit includes a memory cell with a diode and an antifuse in communication with the diode. The antifuse is constructed to include a high-K dielectric material with a K greater than 3.9. Further, the memory cell is programmed utilizing a programming pulse that reverse biases the diode thereof.Type: GrantFiled: July 1, 2005Date of Patent: November 18, 2008Assignee: Sandisk 3D LLCInventor: James M. Cleeves
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Patent number: 7450416Abstract: The present invention is a method of undertaking a procedure on a memory-diode, wherein a memory-diode is provided which is programmable so as to have each of a plurality of different threshold voltages. A reading of the state of the memory-diode indicates the so determined threshold voltage of the memory-diode.Type: GrantFiled: December 23, 2004Date of Patent: November 11, 2008Assignee: Spansion LLCInventors: Swaroop Kaza, Juri Krieger, David Gaun, Stuart Spitzer, Richard Kingsborough, Zhida Lan, Colin S. Bill, Wei Daisy Cai, Igor Sokolik
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Patent number: 7447055Abstract: Various embodiments of the present invention are directed to electronic means for reading the content of a nanowire-crossbar memory. In one embodiment of the present invention, a microscale or sub-microscale signal line is interconnected with one set of parallel nanowires emanating from a nanowire-crossbar memory by configurable, nanowire-junction switches. The microscale or sub-microscale signal line serves as a single-wire multiplexer, allowing the contents of any particular single-bit storage element within the nanowire-crossbar memory to be read in a three-cycle READ operation.Type: GrantFiled: April 22, 2005Date of Patent: November 4, 2008Assignee: Hewlett-Packard Development Company, L.P.Inventors: Philip J. Kuekes, R. Stanley Williams
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Patent number: 7447063Abstract: The nonvolatile semiconductor memory device according the this invention has a plurality of memory cells arranged in a matrix form and each having a floating gate; at least one first diode connected between drains of said plurality of memory cells and a ground terminal; and at least one second diode connected between sources of said plurality of memory cells and said ground terminal, wherein said first diode and said second diode have a same temperature characteristic. Said first diode and said second diode may be of parasitic diodes, Zener diodes or devices with avalanche breakdown voltages.Type: GrantFiled: September 8, 2006Date of Patent: November 4, 2008Assignee: Kabushiki Kaisha ToshibaInventor: Akira Umezawa
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Publication number: 20080239802Abstract: Method and device for providing voltage generation with load-based control are disclosed. The voltage generation can be provided within an electronic device, such as a memory system that provides data storage. In one embodiment, an electrical load imposed on a generated voltage can be monitored and used to dynamically control strength of the generated voltage. For example, for greater electrical loads, the generated voltage can be provided with a greater strength, and for lesser electrical loads, the generated voltage can be provided with a lesser strength. By compensating the generated voltage for the nature of the imposed electrical load, the generated voltage can be provided in a stable manner across a significant range of loads. In the case of a memory system, stability in the generated voltage provides for reduced voltage ripple and thus improved sensing margins. The voltage generation is well suited for use in portable memory products (e.g., memory cards) to generate one or more internal voltages.Type: ApplicationFiled: March 30, 2007Publication date: October 2, 2008Inventors: Tyler Thorp, Ken So
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Publication number: 20080239801Abstract: Methods and apparatus for managing electrical loads of electronic devices are disclosed. According to one embodiment, a current load imposed by an electronic device, such as a memory device (or memory system), can be measured. Then, using the measured current load, the memory device can determine whether (and to what extent) operational performance should be limited. By limiting operational performance, the memory device is able to limit its current load so as to satisfy a specification criterion or other requirement. The electrical load management is well suited for use in portable memory products (e.g., memory cards) to manage current loads being drawn.Type: ApplicationFiled: March 30, 2007Publication date: October 2, 2008Inventors: Tyler Thorp, Ken So
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Publication number: 20080212359Abstract: First electrode layer includes a plurality of first electrode lines (W1, W2) extending parallel to each other. State-variable layer lying on the first electrode layer includes a plurality of state-variable portions (60-11, 60-12, 60-21, 60-22) which exhibits a diode characteristic and a variable-resistance characteristic. Second electrode layer lying on the state-variable layer includes a plurality of second electrode lines (B1, B2) extending parallel to each other. The plurality of first electrode lines and the plurality of second electrode lines are crossing each other when seen in a layer-stacking direction with the state-variable layer interposed therebetween. State-variable portion (60-11) is provided at an intersection of the first electrode line (W1) and the second electrode line (B1) between the first electrode line and the second electrode line.Type: ApplicationFiled: April 21, 2006Publication date: September 4, 2008Inventors: Shunsaku Muraoka, Koichi Osano, Satoru Mitani, Hiroshi Seki
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Patent number: 7417887Abstract: A method and device for driving the word lines of a phase change memory device is provided. The method may include applying a first voltage level to non-selected word lines and a second voltage level to selected word lines during a normal operational mode, and placing the word lines in a floating state during a standby operational mode. The phase change memory device may include a plurality of word line drive circuits for driving corresponding word lines, where each of the plurality of word line drive circuits includes a drive unit which sets a corresponding word line to a first voltage level or a second voltage level in response to a first control signal, and a mode selector which selectively applies the first voltage level to the driving unit according to an operational mode of the phase change memory device.Type: GrantFiled: December 19, 2005Date of Patent: August 26, 2008Assignee: Samsung Electronics Co., Ltd.Inventors: Beak-hyung Cho, Jong-soo Seo, Du-eung Kim, Woo-yeong Cho
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Patent number: 7411810Abstract: In the present invention, one-time programmable memory includes a diode as an access device and a capacitor as a storage device, the diode includes four terminals, wherein the first terminal is connected to a word line, the second terminal is connected to one plate of the capacitor, the third terminal is floating, and the fourth terminal is connected to a bit line, and the capacitor includes two electrodes, wherein one of the capacitor plate serves as a storage node which is connected to the second terminal of the diode, and another plate of the capacitor is connected to a plate line, and the plate line is asserted to programming voltage which is higher than the regular supply voltage of the decoders and data latches, in order to breakdown the insulator of the capacitor when programming, but the plate line is connected to the regular supply voltage when read.Type: GrantFiled: January 30, 2007Date of Patent: August 12, 2008Inventor: Juhan Kim
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Publication number: 20080180981Abstract: A resistance semiconductor memory device of a three-dimensional stack structure, and a word line decoding method thereof, are provided.Type: ApplicationFiled: January 25, 2008Publication date: July 31, 2008Inventors: Joon Min PARK, Sang-Beom KANG, Hyung-Rok OH, Woo-Yeong CHO
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Patent number: 7405960Abstract: A semiconductor memory device and a dummy line biasing method in which in the semiconductor memory device of a diode structure including a plurality of memory cells each having one variable resistance device and one diode device, the memory device includes a plurality of normal word lines, a plurality of normal bit lines, at least one or more dummy word lines and at least one or more dummy bit lines. The plurality of normal word lines are each arrayed in a first direction as a length direction. The plurality of normal bit lines are each arrayed in a second direction as a width direction, intersected with the first direction, so that the plurality of normal bit lines are intersected with the normal word lines. At least one or more dummy word lines are arrayed in the same structure as the normal word lines in the first direction, the at least one or more dummy word lines having a constant level of applied voltage.Type: GrantFiled: April 2, 2007Date of Patent: July 29, 2008Assignee: Samsung Electronics Co., Ltd.Inventors: Beak-Hyung Cho, Hyung-Rok Oh, Chang-Soo Lee
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Patent number: 7379317Abstract: A memory array includes first and second sets of conductors and a plurality of memory-diodes, each connecting in a forward direction a conductor of the first set with a conductor of the second set. An electrical potential is applied across a selected memory-diode, from higher to lower potential in the forward direction, intended to program the selected memory-diode. During this intended programming, each other memory-diode in the array has provided thereacross in the forward direction thereof an electrical potential lower than its threshold voltage. The threshold voltage of each memory-diode can be established by applying an electrical potential across that memory-diode from higher to lower potential in the reverse direction. By so establishing a sufficient threshold voltage, and by selecting appropriate electrical potentials applied to conductors of the array, problems related to current leakage and disturb are avoided.Type: GrantFiled: December 23, 2004Date of Patent: May 27, 2008Assignee: Spansion LLCInventors: Colin S. Bill, Swaroop Kaza, Tzu-Ning Fang, Stuart Spitzer
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Publication number: 20080117672Abstract: A gated diode nonvolatile memory cell with a charge storage structure includes a diode structure with an additional gate terminal and a diffusion barrier structure between the diode nodes. Example embodiments include the individual memory cell, an array of such memory cells, methods of operating the memory cell or array of memory cells, and methods of manufacturing the same.Type: ApplicationFiled: January 2, 2007Publication date: May 22, 2008Applicant: Macronix International Co., Ltd.Inventors: Hsuan Ling Kao, Wen Jer Tsai, Tien Fan Ou
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Publication number: 20080117673Abstract: A gated diode nonvolatile memory cell with a charge storage structure includes a diode structure with an additional gate terminal and a diffusion barrier structure between the diode nodes. Example embodiments include the individual memory cell, an array of such memory cells, methods of operating the memory cell or array of memory cells, and methods of manufacturing the same.Type: ApplicationFiled: January 2, 2007Publication date: May 22, 2008Applicant: Macronix International Co., Ltd.Inventors: Hsuan Ling Kao, Wen Jer Tsai, Tien Fan Ou, Yi Ying Liao
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Patent number: 7376008Abstract: One of the simplest forms of data storage devices is the diode array storage device. However, a problem with diode array storage devices is that as the size of the array increases, the number of non-addressed diodes connected between a given selected row or column of the array and the non-addressed columns or rows of the array, respectively, also becomes very large. While the leakage current through any one non-addressed diode on the selected row or column will have little impact on the operation of the device, the cumulative leakage through multiple thousands of non-addressed diodes can become significant. This aggregate leakage current can become great enough that the output voltage can be shifted such that the threshold for distinguishing between a one state and a zero state of the addressed diode location can become obscured and can result in a misreading of the addressed diode location. The present invention is a means to manage the leakage currents in a diode array storage device.Type: GrantFiled: August 6, 2004Date of Patent: May 20, 2008Assignee: Contour Seminconductor, Inc.Inventor: Daniel Robert Shepard
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Patent number: 7372306Abstract: A method and state stabilizer for enhancing computing functionality by using fast excitations are described. The state stabilizer includes a voltage source for producing fast excitations having an associated excitation amplitude. An electronic device having an associated negative differential resistance region is also included. The excitation amplitude is greater than a width of the negative differential resistance region.Type: GrantFiled: February 14, 2006Date of Patent: May 13, 2008Assignee: The Regents of the University of CaliforniaInventors: Alexander Khitun, Kang L. Wang
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Patent number: 7362609Abstract: A one-transistor (1T) NVRAM cell that utilizes silicon carbide (SiC) to provide both isolation of non equilibrium charge, and fast and non destructive charging/discharging. To enable sensing of controlled resistance (and many memory levels) rather than capacitance, the cell incorporates a memory transistor that can be implemented in either silicon or Sic. The 1T cell has diode isolation to enable implementation of the architectures used in the present flash memories, and in particular the NOR and the NAND arrays. The 1T cell with diode isolation is not limited to SiC diodes. The fabrication method includes the step of forming a nitrided silicon oxide gate on the Sic substrate and subsequently carrying out the ion implantation and then finishing the formation of a self aligned MOSFET.Type: GrantFiled: September 12, 2003Date of Patent: April 22, 2008Assignee: Griffith UniversityInventors: Barry H. Harrison, Sima Dimitrijev
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Patent number: 7352610Abstract: Memory elements are provided that are immune to soft error upset events when subjected to high-energy atomic particle strikes. The memory elements have nonlinear high-impedance two-terminal elements that restrict the flow of discharge currents during a particle strike. By lengthening the switching speed of the memory elements, the presence of the nonlinear high-impedance two-terminal elements prevents the states of the memory elements from flipping during discharge transients. The nonlinear high-impedance two-terminal elements may be formed from polysilicon p-n junction diodes, Schottky diodes, and other semiconductor structures. Data loading circuitry is provided to ensure that memory element arrays using the nonlinear high-impedance two-terminal elements can be loaded rapidly.Type: GrantFiled: December 6, 2005Date of Patent: April 1, 2008Assignee: Altera CorporationInventors: Bruce B. Pedersen, Irfan Rahim, Jeffrey T Watt
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Patent number: 7352617Abstract: A nano tube cell and a memory device using the same features a cross point cell using a capacitor and a PNPN nano tube switch to reduce the whole memory size. In the memory device, the unit nano tube cell comprising a capacitor and a PNPN nano tube switch which does not an additional gate control signal is located where a word line and a bit line are crossed, so that a cross point cell array is embodied. As a result, the whole chip size is reduced, and read and write operations are effectively improved.Type: GrantFiled: February 16, 2005Date of Patent: April 1, 2008Assignee: Hynix Semiconductor Inc.Inventor: Hee Bok Kang
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Patent number: 7349273Abstract: An access circuit selectively couples an externally accessible terminal to each of a plurality of isolated DRAM wells in which respective DRAM arrays are fabricated. The access circuit for each well includes first and second transistors fabricated in respective wells coupled between the externally accessible terminal and a respective one of the DRAM wells. The well of the first transistor is coupled to the externally accessible terminal, and the well of the other transistor is coupled to a respective DRAM well. A control circuit applies select signals to gate electrodes of the first and second transistors. The control circuit includes respective shunt transistors that shunt the gate electrodes to the source regions of the first and second transistors when the transistors are turned off to isolate the respective DRAM wells from the external terminal regardless of the magnitude and polarity of a test voltage applied to the externally accessible terminal.Type: GrantFiled: October 27, 2006Date of Patent: March 25, 2008Assignee: Micron Technology, Inc.Inventor: David A. Zimlich
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Patent number: 7349248Abstract: A non-volatile memory cell includes an upper electrode; a lower electrode and a state-variable region, in which a conductive state changes only once. The state variable region is formed in a region between the upper electrode and the lower electrode. The state-variable region comprises a first semiconductor layer of a first conductive type; and second semiconductor layers of a second conductive type, opposing to the first conductive type, which are formed on upper and lower surfaces of the first semiconductor layer via PN junctions.Type: GrantFiled: January 24, 2007Date of Patent: March 25, 2008Assignee: Oki Electric Industry Co., Ltd.Inventors: Yoshiyuki Kawazu, Hiroyuki Tanaka
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Publication number: 20080023790Abstract: A mixed-use memory array is disclosed. In one preferred embodiment, a memory array is provided comprising a first set of memory cells operating as one-time programmable memory cells and a second set of memory cells operating as rewritable memory cells. In another preferred embodiment, a memory array is provided comprising a first set of memory cells operating as memory cells that are programmed with a forward bias and a second set of memory cells operating as memory cells that are programmed with a reverse bias.Type: ApplicationFiled: July 31, 2006Publication date: January 31, 2008Inventor: Roy E. Scheuerlein
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Publication number: 20080025062Abstract: A method for using a mixed-use memory array with different data states is disclosed. In one preferred embodiment, a memory array is provided comprising a plurality of memory cells, each memory cell comprising a memory element comprising a switchable resistance material configurable to one of at least three resistivity states. A first set of memory cells uses X resistivity states to represent X respective data states, and a second set of memory cells uses Y resistivity states to represent Y respective data states, wherein X?Y.Type: ApplicationFiled: July 31, 2006Publication date: January 31, 2008Inventors: Roy E. Scheuerlein, Christopher J. Petti
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Patent number: 7310266Abstract: A DAC having a memory mat including a plurality of first memory cells, and a plurality of output lines connected to the plurality of first memory cells. Each of the plurality of memory cells has a first memory portion including bipolar transistors and storing information in non-volatility based on whether a junction of the bipolar transistors is destroyed or not, and a second memory portion connected to the first memory portion and for outputting information to corresponding one of the plurality of output lines. The DAC has a first mode in which information is transferred from the first memory portions to the second memory portions when the information is written into the second memory portions, and a second mode in which the second memory portions are specified externally and information is written into the second memory portions.Type: GrantFiled: April 25, 2006Date of Patent: December 18, 2007Assignee: Hitachi, Ltd.Inventors: Ryusuke Sahara, Mitsugu Kusunoki, Kazutaka Mori, Hiroshige Kogayu
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Patent number: 7310259Abstract: An access circuit selectively couples an externally accessible terminal to each of a plurality of isolated DRAM wells in which respective DRAM arrays are fabricated. The access circuit for each well includes first and second transistors fabricated in respective wells coupled between the externally accessible terminal and a respective one of the DRAM wells. The well of the first transistor is coupled to the externally accessible terminal, and the well of the other transistor is coupled to a respective DRAM well. A control circuit applies select signals to gate electrodes of the first and second transistors. The control circuit includes respective shunt transistors that shunt the gate electrodes to the source regions of the first and second transistors when the transistors are turned off to isolate the respective DRAM wells from the external terminal regardless of the magnitude and polarity of a test voltage applied to the externally accessible terminal.Type: GrantFiled: May 23, 2006Date of Patent: December 18, 2007Assignee: Micron Technology, Inc.Inventor: David A. Zimlich
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Patent number: 7304888Abstract: A memory array having memory cells each comprising a diode and a phase change material or antifuse is reliably programmed by maintaining all word lines and bit lines connected to unselected memory cells at intermediate voltages and applying voltages to place the diode of a selected cell or cells in a reverse biased state and sufficient to program the phase change material or antifuse. Thus leakage through unselected cells is low so power wasted is small, and assurance is high that no unselected memory cells are disturbed.Type: GrantFiled: July 1, 2005Date of Patent: December 4, 2007Assignee: Sandisk 3D LLCInventor: N. Johan Knall
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Nano tube cell, and semiconductor device having nano tube cell and double bit line sensing structure
Patent number: 7298645Abstract: The present invention discloses a nano tube cell, and a semiconductor device having the nano tube cell and a double bit line sensing structure. The cell array circuit includes a plurality of top sub cell arrays, a plurality of bottom sub cell arrays, a main bit line sense amp and a word line driving unit. Especially, the top and bottom sub cell arrays have a double bit line sensing structure for inducing a sensing voltage of a main bit line by controlling a volume of a current supplied from a power voltage to the main bit line according to a sensing voltage of a sub bit line receiving a cell data. Each of the sub cell arrays includes a capacitor, and a PNPN nano tube cell having a PNPN diode switch selectively turned on/off according to a voltage difference between one side terminal of the capacitor and the sub bit line, to decrease a cell size and improve operational characteristics of the circuit.Type: GrantFiled: August 9, 2006Date of Patent: November 20, 2007Assignee: Hynix Semiconductor Inc.Inventor: Hee Bok Kang -
Publication number: 20070258285Abstract: A non-volatile memory cell includes an upper electrode; a lower electrode and a state-variable region, in which a conductive state changes only once. The state variable region is formed in a region between the upper electrode and the lower electrode. The state-variable region comprises a first semiconductor layer of a first conductive type; and second semiconductor layers of a second conductive type, opposing to the first conductive type, which are formed on upper and lower surfaces of the first semiconductor layer via PN junctions.Type: ApplicationFiled: January 24, 2007Publication date: November 8, 2007Applicant: OKI ELECTRIC INDUSTRY CO., LTD.Inventors: Yoshiyuki Kawazu, Hiroyuki Tanaka
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Patent number: 7283388Abstract: A memory device features a multiple layer nano tube cell. In the memory device, a cross point cell array including a capacitor and a PNPN nano tube switch is effectively arranged to reduce the whole memory size. Also, in the memory device, the nano tube cell array including a capacitor and a PNPN nano tube switch which does not require an additional gate control signal is positioned on a circuit device region including a word line driving unit, a sense amplifier, a data bus, a main amplifier, a data buffer and an input/output port, and an interlayer insulating film is interposed between a cell array region and the circuit device region.Type: GrantFiled: February 16, 2005Date of Patent: October 16, 2007Assignee: Hynix Semiconductor Inc.Inventor: Hee Bok Kang
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Patent number: 7283383Abstract: A nonvolatile memory device features a phase change resistor cell as a cross-point cell using a phase change resistor and a serial diode switch. The phase change resistor has logic data corresponding to a crystallization state changed by the amount of current supplied from a word line. The serial diode switch, connected between the phase change resistor and a bit line, comprises at least two or more diode switches serially connected, wherein each end portion of the diode switch is connected in common to the phase change resistor and the bit line and selectively switched depending on voltages applied to the word line and the bit line. The nonvolatile memory device is configured with the phase change resistor cell, and voltages applied to a word line and a bit line are controlled to read and write data. As a result, the whole size of the memory device is reduced.Type: GrantFiled: June 28, 2004Date of Patent: October 16, 2007Assignee: Hynix Semiconductor Inc.Inventor: Hee Bok Kang