Patents by Inventor Tomonori Sekiguchi

Tomonori Sekiguchi has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20110110150
    Abstract: A highly reliable large capacity phase change memory module is realized. A semiconductor device according to the present invention includes a memory array having a structure in which a storage layer using a chalcogenide material and a memory cell constituted of a diode are stacked, and an initialization condition and a rewriting condition are changed in accordance with the layer where a selected memory cell is located. A current mirror circuit is selected in accordance with an operation, and at the same time, the initialization condition and the rewriting condition (here, reset condition) are changed in accordance with the operation by a control mechanism of the reset current in a voltage selection circuit and a current mirror circuit.
    Type: Application
    Filed: January 18, 2011
    Publication date: May 12, 2011
    Inventors: SATORU HANZAWA, Hitoshi Kume, Motoyasu Terao, Tomonori Sekiguchi, Makoto Sean
  • Publication number: 20110103136
    Abstract: A sense amplifier is constructed to reduce the occurrence of malfunctions in a memory read operation, and thus degraded chip yield, due to increased offset of the sense amplifier with further sealing down. The sense amplifier circuit is constructed with a plurality of pull-down circuits and a pull-up circuit, and a transistor in one of the plurality of pull-down circuits has a constant such as a channel length or a channel width larger than that of a transistor in another pull-down circuit. The pull-down circuit with a larger constant of a transistor is first activated, and then, the other pull-down circuit and the pull-up circuit are activated to perform the read operation.
    Type: Application
    Filed: November 3, 2010
    Publication date: May 5, 2011
    Inventors: Satoru Akiyama, Riichiro Takemura, Takayuki Kawahara, Tomonori Sekiguchi
  • Patent number: 7933141
    Abstract: In a semiconductor memory device, a memory cell is connected with a local sense amplifier and a global sense amplifier via a local bit line and a global bit line. The local sense amplifier is a single-ended sense amplifier including a single MOS transistor, which detects a potential of the local bit line which varies when reading and writing data with the memory cell. The threshold voltage of the MOS transistor is monitored so as to produce a high-level write voltage and a low-level write voltage, which are corrected and shifted based on the monitoring result so as to properly perform a reload operation on the memory cell by the global local sense amplifier. Thus, it is possible to cancel out temperature-dependent variations of the threshold voltage and shifting of the threshold voltage due to dispersions of manufacturing processes.
    Type: Grant
    Filed: April 1, 2009
    Date of Patent: April 26, 2011
    Assignee: Elpida Memory, Inc.
    Inventors: Kazuhiko Kajigaya, Soichiro Yoshida, Tomonori Sekiguchi, Riichiro Takemura, Yasutoshi Yamada
  • Publication number: 20110079858
    Abstract: A semiconductor memory device having high integration, low power consumption and high operation speed. The memory device includes a sense amplifier circuit having plural pull-down circuits and a pull-up circuit. A transistor constituting one of the plural pull-down circuits has a larger constant than that of a transistor constituting the other pull-down circuits, for example, a channel length and a channel width. The pull-down circuit having the larger constant transistor is activated earlier than the other pull-down circuits and the pull-up circuit, which are activated to conduct reading. The data line and the earlier driven pull-down circuit are connected by an NMOS transistor and the NMOS transistor is activated or inactivated to control the activation or inactivation of the pull-down circuit.
    Type: Application
    Filed: December 14, 2010
    Publication date: April 7, 2011
    Inventors: Satoru Akiyama, Tomonori Sekiguchi, Riichiro Takemura, Hiroaki Nakaya, Shinichi Miyatake, Yuko Watanabe
  • Patent number: 7903492
    Abstract: Disclosed is a semiconductor device including a first clock generator that generates a first clock signal having a first period from an input clock signal, a second clock generator that generates a second clock signal having a second period from the input clock signal, and a timing generator that receives the first clock signal, the second clock signal, an activation signal from a command decoder and a selection signal for selecting the delay time from a timing register to produce a timing signal delayed as from activation of the activation signal by a delay equal to a sum of a time equal to a preset number m prescribed by the selection signal times the first period and a time equal to another preset number n prescribed by the selection signal times the second period. The timing register holds the values of m and n. These values are set in the timing register in an initialization sequence at the time of a mode register set command.
    Type: Grant
    Filed: December 17, 2008
    Date of Patent: March 8, 2011
    Assignee: Elpida Memory, Inc.
    Inventors: Akira Ide, Yasuhiro Takai, Tomonori Sekiguchi, Riichiro Takemura, Satoru Akiyama, Hiroaki Nakaya
  • Patent number: 7903449
    Abstract: A semiconductor memory device (e.g. DRAM) is constituted of a memory cell array including a plurality of memory cells, a plurality of word line drivers, a plurality of sense amplifiers, and a plurality of dummy capacitors. The memory cells, each of which includes a transistor and a capacitor, are positioned at intersections between the word lines and the bit lines. The first electrodes of the capacitors are connected to the transistors in the memory cells. The first electrodes of the dummy capacitors are connected together and are supplied with a second potential (e.g. VDD or VSS). The second electrodes of the dummy capacitors are connected together with the second electrodes of the capacitors of the memory cells and are supplied with a first potential (e.g. VPL). The dummy capacitors serve as smoothing capacitances for the plate voltage VPL so as to reduce plate noise.
    Type: Grant
    Filed: June 16, 2009
    Date of Patent: March 8, 2011
    Assignee: Elpida Memory, Inc.
    Inventors: Kazuhiko Kajigaya, Soichiro Yoshida, Tomonori Sekiguchi, Riichiro Takemura, Yasutoshi Yamada
  • Publication number: 20110044092
    Abstract: A resistance variable memory reduces the nonuniformity of resistance values after programming, so that a rewrite operation can be performed on a memory cell at high speed. A reference resistor is connected in series with the resistance variable memory cell, and a sensor amplifier detects whether the potential at an intermediate node between the memory cell and the reference resistor exceeds a given threshold voltage, so as to stop the write operation based on a detection result.
    Type: Application
    Filed: October 30, 2010
    Publication date: February 24, 2011
    Inventors: KAZUO ONO, Riichiro Takemura, Tomonori Sekiguchi
  • Patent number: 7894232
    Abstract: A highly reliable large capacity phase change memory module is realized. A semiconductor device according to the present invention includes a memory array having a structure in which a storage layer using a chalcogenide material and a memory cell constituted of a diode are stacked, and an initialization condition and a rewriting condition are changed in accordance with the layer where a selected memory cell is located. A current mirror circuit is selected in accordance with an operation, and at the same time, the initialization condition and the rewriting condition (here, reset condition) are changed in accordance with the operation by a control mechanism of the reset current in a voltage selection circuit and a current mirror circuit.
    Type: Grant
    Filed: April 21, 2009
    Date of Patent: February 22, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Satoru Hanzawa, Hitoshi Kume, Motoyasu Terao, Tomonori Sekiguchi, Makoto Saen
  • Patent number: 7876627
    Abstract: A semiconductor memory device having high integration, low power consumption and high operation speed. The memory device includes a sense amplifier circuit having plural pull-down circuits and a pull-up circuit. A transistor constituting one of the plural pull-down circuits has a larger constant than that of a transistor constituting the other pull-down circuits, for example, a channel length and a channel width. The pull-down circuit having the larger constant transistor is activated earlier than the other pull-down circuits and the pull-up circuit, which are activated to conduct reading. The data line and the earlier driven pull-down circuit are connected by an NMOS transistor and the NMOS transistor is activated or inactivated to control the activation or inactivation of the pull-down circuit.
    Type: Grant
    Filed: January 3, 2008
    Date of Patent: January 25, 2011
    Assignees: Hitachi, Ltd., Elpida Memory, Inc.
    Inventors: Satoru Akiyama, Tomonori Sekiguchi, Riichiro Takemura, Hiroaki Nakaya, Shinichi Miyatake, Yuko Watanabe
  • Patent number: 7848177
    Abstract: The semiconductor integrated circuit device includes: a first latch which can hold an output signal of the X decoder and transfer the signal to the word driver in a post stage subsequent to the X decoder; a second latch which can hold an output signal of the Y decoder and transfer the signal to the column multiplexer in the post stage subsequent to the Y decoder; and a third latch which can hold an output signal of the sense amplifier and transfer the signal to the output buffer in the post stage subsequent to the sense amplifier. The structure makes it possible to pipeline-control a series of processes for reading data stored in the non-volatile semiconductor memory, and enables low-latency access even with access requests from CPUs conflicting.
    Type: Grant
    Filed: November 12, 2008
    Date of Patent: December 7, 2010
    Assignee: Renesas Electronics Corporation
    Inventors: Shinya Kajiyama, Yutaka Shinagawa, Makoto Mizuno, Hideo Kasai, Takao Watanabe, Riichiro Takemura, Tomonori Sekiguchi
  • Patent number: 7843250
    Abstract: A substrate voltage control technique that prevents the operating speed from being decreased and suppresses a leakage current due to a lower threshold voltage with respect to a low voltage use. Since a center value of the threshold voltages is detected by plural replica MOS transistors, and a substrate voltage is controlled to control a center value of the threshold voltages, thereby making it possible to satisfy a lower limit of the operating speed and an upper limit of a leakage current of the entire chip. On the other hand, the substrate voltage is dynamically controlled during the operation of the chip, thereby making it possible to decrease the center value of the threshold voltages when the chip operates to improve the speed, and to increase the center value of the threshold voltages after the operation of the chip to reduce the leakage current of the entire chip.
    Type: Grant
    Filed: January 13, 2010
    Date of Patent: November 30, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Hiroaki Nakaya, Satoru Akiyama, Tomonori Sekiguchi, Riichiro Takemura
  • Patent number: 7843751
    Abstract: A sense amplifier is constructed to reduce the occurrence of malfunctions in a memory read operation, and thus degraded chip yield, due to increased offset of the sense amplifier with further sealing down. The sense amplifier circuit is constructed with a plurality of pull-down circuits and a pull-up circuit, and a transistor in one of the plurality of pull-down circuits has a constant such as a channel length or a channel width larger than that of a transistor in another pull-down circuit. The pull-down circuit with a larger constant of a transistor is first activated, and then, the other pull-down circuit and the pull-up circuit are activated to perform the read operation.
    Type: Grant
    Filed: January 12, 2009
    Date of Patent: November 30, 2010
    Assignee: Hitachi, Ltd
    Inventors: Satoru Akiyama, Riichiro Takemura, Takayuki Kawahara, Tomonori Sekiguchi
  • Patent number: 7835171
    Abstract: A resistance variable memory reduces the nonuniformity of resistance values after programming, so that a rewrite operation can be performed on a memory cell at high speed. A reference resistor is connected in series with the resistance variable memory cell, and a sensor amplifier detects whether the potential at an intermediate node between the memory cell and the reference resistor exceeds a given threshold voltage, so as to stop the write operation based on a detection result.
    Type: Grant
    Filed: July 11, 2008
    Date of Patent: November 16, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Ono, Riichiro Takemura, Tomonori Sekiguchi
  • Publication number: 20100277996
    Abstract: A sense amplifier capable of performing high-speed data sense operation with lower power consumption using a minuscule signal from a memory cell even in a case where a memory array voltage is reduced. A plurality of drive switches for over-driving are distributively arranged in a sense amplifier area, and a plurality of drive switches for restore operation are concentratively disposed at one end of a row of the sense amplifiers. A potential for over-driving is supplied using a meshed power line circuit. Through the use of the drive switches for over-driving, initial sense operation can be performed on data line pairs with a voltage having an amplitude larger than a data-line amplitude, allowing implementation of high-speed sense operation. The distributed arrangement of the drive switched for over-driving makes it possible to dispersively supply current in sense operation, thereby reducing a difference in sense voltage with respect to far and near positions of the sense amplifiers.
    Type: Application
    Filed: February 8, 2008
    Publication date: November 4, 2010
    Inventors: Riichiro TAKEMURA, Kiyoo ITOH, Tomonori SEKIGUCHI, Takeshi SAKATA, Katsutaka KIMURA
  • Patent number: 7821804
    Abstract: In a large scale integrated DRAM in pursuit of micro fabrication, data line-word line coupling capacitances are unbalanced between paired data lines. An imbalance in data line-word line means generation of large noise when the data lines are subjected to amplification, which is highly likely invite deterioration of very small signals on the data lines and erroneous amplification of data. One or a few each of a plurality of word lines connected to a plurality of memory cells connected to one data line are alternately connected to subword driver arrays arranged on the opposing sides of a memory array. Positive and negative word line noise components cancel each other in the subword drivers when the data lines are subjected to amplification, so that the word line noise can be reduced. Therefore, signals read out by sense amplifiers can be prevented from deterioration thereby to increase the reliability of memory operation.
    Type: Grant
    Filed: September 6, 2007
    Date of Patent: October 26, 2010
    Assignee: Elpida Memory, Inc.
    Inventors: Tomonori Sekiguchi, Riichiro Takemura, Kazuhiko Kajigaya, Katsutaka Kimura, Tsugio Takahashi
  • Patent number: 7809920
    Abstract: In an information processor including memory devices such as DRAMs and others, by reducing the power consumption of memory devices and efficiently repairing defect bits, a highly reliable information processor is realized. In an information processor including an external memory such as a DRAM, a second memory whose power consumption at the access time is smaller than that of the external memory is disposed, and cache data of the external memory and repair data are stored in this second memory. To an input address given from a central processing unit via a primary cache controller, a memory controller determines a hit or a miss with reference to a tag memory for cache and a tag memory for repair, and when one or both of tag memory for cache and a tag memory for repair are hit, it accesses the second memory.
    Type: Grant
    Filed: February 8, 2007
    Date of Patent: October 5, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Takao Watanabe, Motokazu Ozawa, Tomonori Sekiguchi
  • Patent number: 7804700
    Abstract: A semiconductor device includes a plurality of word lines, a plurality of bit lines, a plurality of memory cells provided at the intersections of the plurality of word lines and the plurality of bit lines and each of that includes a MIS transistor and a memory element, a decoder circuit for selecting a plurality of word lines, and a sense-amplifier circuit for determining information that is read from any of the plurality of memory cells to any of the plurality of bit lines, wherein a twist connector for switching the wiring order of the plurality of word lines is provided and level-stabilizing circuits, for supplying the potential level of a non-selected state to the plurality of word lines in the non-selected state are arranged in the area below the twist connector.
    Type: Grant
    Filed: December 23, 2008
    Date of Patent: September 28, 2010
    Assignee: Elpida Memory, Inc.
    Inventors: Yasutoshi Yamada, Tomonori Sekiguchi, Riichiro Takemura, Kazuhiko Kajigaya
  • Patent number: 7772911
    Abstract: Disclosed is a timing control circuit that receives a first clock having a period T1, a group of second clocks of L different phases spaced apart from each other at substantially equal intervals and selection signals m, n supplied thereto and generates a fine timing signal delayed from the rising edge of the first clock signal by a delay td of approximately td=m·T1+n·(T2/L). The timing control circuit includes a coarse delay circuit and a fine delay circuit. The coarse delay circuit includes a counter for counting a rising edge of the first clock signal after an activate signal is activated and generates a coarse timing signal whose amount of delay from the first clock signal is approximately m·T1.
    Type: Grant
    Filed: September 11, 2008
    Date of Patent: August 10, 2010
    Assignee: Elpida Memory, Inc.
    Inventors: Akira Ide, Yasuhiro Takai, Tomonori Sekiguchi, Riichiro Takemura, Satoru Akiyama, Hiroaki Nakaya
  • Patent number: 7750712
    Abstract: A timing control circuit DLY1 receives clock signal CKa with period T1 and activation signal ACT and outputs fine timing signal FT with delay of m*T1+tda measured from the clock signal where m denotes a non-negative integer and tda denotes delay in the analog delay element. The timing control circuit DLY1 comprises a coarse delay circuit CD and a fine delay circuit FD. The coarse delay circuit CD comprises a counter for counting a rising edge of the clock signal CKa after receiving activation signal ACT and outputs coarse timing signal CT with delay of m*T1 measured from a rising edge of the clock signal CKa. The fine delay circuit FD comprises a plurality of analog delay elements and outputs fine delay timing signal FT with delay of tda measured from the coarse timing signal CT. Variation in delay of timing signal is reduced.
    Type: Grant
    Filed: December 5, 2008
    Date of Patent: July 6, 2010
    Assignee: Elpida Memory, Inc.
    Inventors: Akira Ide, Yasuhiro Takai, Akira Kotabe, Tomonori Sekiguchi, Riichiro Takemura, Satoru Akiyama
  • Publication number: 20100155921
    Abstract: The need for mediation operation is eliminated by adoption of a connection topology in which a circuit for executing one transmission (TR—00T), and a circuit for executing a plurality of receptions (TR—10R, TR—20R, TR—30R) are connected to one penetration-electrode group (for example, TSVGL—0). In order to implement the connection topology even in the case of piling up a plurality of LSIs one after another, in particular, a programmable memory element for designating respective penetration-electrode ports for use in transmit, or for us in receive, and address allocation of the respective penetration-electrode ports is mounted in stacked LSIs.
    Type: Application
    Filed: December 13, 2009
    Publication date: June 24, 2010
    Inventors: Makoto SAEN, Kenichi Osada, Masanao Yamaoka, Tomonori Sekiguchi