Patents by Inventor Riichiro Takemura

Riichiro Takemura 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: 20090129136
    Abstract: If memory cell blocks are laid out in a conventional manner to create a memory chip with a capacity of an odd power of 2 by using memory cells whose aspect ratio is 1:2, the chip will take a 1:1 shape and become difficult to enclose in a package of a 1:2 shape. In addition, such conventional layout of memory cell blocks to form the 1:2 shape causes the area of a peripheral circuit region to be limited by the memory blocks, pads to be arranged collectively in the central section of the chip, and wiring to become dense during the enclosure of the chip in the package. In this invention, therefore, four memory blocks, BANK0, BANK1, BANK2, BANK3, BANK3, are constructed into an L shape and then these memory blocks are properly combined and arranged to construct a chip of nearly a 1:2 shape in terms of aspect ratio.
    Type: Application
    Filed: January 15, 2009
    Publication date: May 21, 2009
    Inventors: Riichiro TAKEMURA, Tomonori SEKIGUCHI
  • Publication number: 20090122602
    Abstract: There is achieved a high-integrated and high-speed nonvolatile memory which can stabilize an operation of a phase-change memory for a short operation cycle time. A latch is provided in a write driver. A change to a high-resistance state of a phase-change element is performed per column cycle by a write-enable signal, and a change to a low-resistance state thereof is performed after a pre-charge command is inputted and concurrently with deactivation of a pre-charge signal. Thereby, a write time to a memory cell in which phase-change resistance is changed to a low-resistance state, and a period from a write operation for changing the phase-change resistance to a high-resistance state to a read operation to the above memory cell can be lengthened without extending the column cycle time, so that the stable write operation is achieved.
    Type: Application
    Filed: January 13, 2009
    Publication date: May 14, 2009
    Inventors: RIICHIRO TAKEMURA, Takeshi Sakata, Norikatsu Takaura, Kazuhiko Kajigaya
  • Publication number: 20090116309
    Abstract: A column circuit that amplifies signals read from a sense amplifier array SAA to local input/output lines LIO in sub-amplifiers SAMP to transfer the amplified signals to main input/output lines MIO is provided. A current control circuit IC that can set one of two kinds of currents according to read enable signals RD1, RD2 is provided in each sub-amplifier SAMP. The read enable signals RD1, RD2 are generated at timings corresponding to the number of cycles in burst read operation under control of the timing controller. Current in the current control circuit IC is set to be large by the RD1 in burst read operation cycle just after activation of a memory bank, while current in the current control circuit IC is set to be small by the RD2 in the next and subsequent burst read cycles. Accordingly, expansion of an operation margin or reduction of power consumption can be realized in a semiconductor device including a semiconductor memory such as a DRAM.
    Type: Application
    Filed: January 4, 2009
    Publication date: May 7, 2009
    Inventors: SATORU HANZAWA, Tomonori Sekiguchi, Riichiro Takemura, Satoru Akiyama, Kazuhiko Kajigaya
  • Publication number: 20090102524
    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: Application
    Filed: September 11, 2008
    Publication date: April 23, 2009
    Applicant: ELPIDA MEMORY, INC
    Inventors: Akira Ide, Yasuhiro Takai, Tomonori Sekiguchi, Riichiro Takemura, Satoru Akiyama, Hiroaki Nakaya
  • Publication number: 20090086551
    Abstract: Disclosed is a semiconductor device in which In case a data group output from a first output pin in a first word configuration is output from the first output pin and a second output pin in a second word configuration, and a data group output from a third output pin in a first word configuration is output from the third output pin and a fourth output pin in a second word configuration, the second output pin is arranged adjacent to the first output pin, and the fourth output pin is arranged adjacent to the third output pin.
    Type: Application
    Filed: September 30, 2008
    Publication date: April 2, 2009
    Inventors: Akira Ide, Yasuhiro Takai, Riichiro Takemura, Tomonori Sekiguchi
  • Patent number: 7505299
    Abstract: A semiconductor memory device that can achieve high-speed operation or that is highly integrated and simultaneously can achieve high-speed operation is provided. Transistors are disposed on both sides of diffusion layer regions to which capacitor for storing information is connected and other diffusion layer region of each transistor is connected to the same bit line. When access to a memory cell is made, two transistors are activated and the information is read. When writing operation to the memory cell is carried out, two transistors are used and electric charges are written to the capacitor.
    Type: Grant
    Filed: October 25, 2007
    Date of Patent: March 17, 2009
    Assignees: Hitachi Ltd., Elpida Memory, Inc.
    Inventors: Riichiro Takemura, Satoru Akiyama, Satoru Hanzawa, Tomonori Sekiguchi, Kazuhiko Kajigaya
  • Publication number: 20090066390
    Abstract: Disclosed is a timing control circuit which receives a first clock having a period T1 and a group of second clocks of L different phases (where L is a positive integer) spaced apart from each other at substantially equal intervals and which generates a fine timing signal delayed from the rising edge of the first clock by a delay td of approximately td=m·T1+n·(T2/L), where m and n are non-negative integers. The timing control circuit has a coarse delay circuit and a fine delay circuit. The coarse delay circuit counts the rising edges of the first clock after an activate signal is activated and generates a coarse timing signal delayed from the first clock by approximately m·T1. The fine delay circuit has a circuit which, after the activate signal is activated, detects a second clock, which has a rising edge that immediately follows the rising edge of the first clock, from among the group of L-phase second clocks.
    Type: Application
    Filed: September 5, 2008
    Publication date: March 12, 2009
    Applicant: ELPIDA MEMORY, INC.
    Inventors: Akira IDE, Yasuhiro TAKAI, Tomonori SEKIGUCHI, Riichiro TAKEMURA, Satoru AKIYAMA, Hiroaki NAKAYA
  • Publication number: 20090059702
    Abstract: A direct sense amplifier of the present invention incorporates and isolates: an MOS transistor serving as a differential pair and having a gate connected to a bit line; and an MOS transistor controlled by a column select line wired between RLIO lines in a bit-line direction, and further connects a source of the MOS transistor serving as the differential pair to a common source line wired in the word-line direction. Since the direct sense amplifier only in a select map is activated by the column select line and the common source line during an read operation, power consumption is significantly reduced during the read operation. Also, since a parasitic capacitance of the MOS transistor serving as the differential pair is separated from the local IO line, a load capacity of the local IO line is reduced and the read operation is speeded up. In addition, during the read operation, a data pattern dependency of the load capacity of the local IO line is reduced and a post-manufacture test is easily made.
    Type: Application
    Filed: October 8, 2008
    Publication date: March 5, 2009
    Inventors: Tomonori Sekiguchi, Shinichi Miyatake, Takeshi Sakata, Riichiro Takemura, Hiromasa Noda, Kazuhiko Kajigaya
  • Patent number: 7495943
    Abstract: If memory cell blocks are laid out in a conventional manner to create a memory chip with a capacity of an odd power of 2 by using memory cells whose aspect ratio is 1:2, the chip will take a 1:1 shape and become difficult to enclose in a package of a 1:2 shape. In addition, such conventional layout of memory cell blocks to form the 1:2 shape causes the area of a peripheral circuit region to be limited by the memory blocks, pads to be arranged collectively in the central section of the chip, and wiring to become dense during the enclosure of the chip in the package. In this invention, therefore, four memory blocks, BANK0, BANK1, BANK2, BANK3, BANK3, are constructed into an L shape and then these memory blocks are properly combined and arranged to construct a chip of nearly a 1:2 shape in terms of aspect ratio.
    Type: Grant
    Filed: January 22, 2007
    Date of Patent: February 24, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Riichiro Takemura, Tomonori Sekiguchi
  • Patent number: 7492644
    Abstract: There is achieved a high-integrated and high-speed nonvolatile memory which can stabilize an operation of a phase-change memory for a short operation cycle time. A latch is provided in a write driver. A change to a high-resistance state of a phase-change element is performed per column cycle by a write-enable signal, and a change to a low-resistance state thereof is performed after a pre-charge command is inputted and concurrently with deactivation of a pre-charge signal. Thereby, a write time to a memory cell in which phase-change resistance is changed to a low-resistance state, and a period from a write operation for changing the phase-change resistance to a high-resistance state to a read operation to the above memory cell can be lengthened without extending the column cycle time, so that the stable write operation is achieved.
    Type: Grant
    Filed: August 2, 2007
    Date of Patent: February 17, 2009
    Assignees: Hitachi, Ltd., Elpida Memory, Inc.
    Inventors: Riichiro Takemura, Takeshi Sakata, Norikatsu Takaura, Kazuhiko Kajigaya
  • Patent number: 7492655
    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: April 19, 2007
    Date of Patent: February 17, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Satoru Akiyama, Riichiro Takemura, Takayuki Kawahara, Tomonori Sekiguchi
  • Publication number: 20090039335
    Abstract: On an insulating film (31) in which a plug (35) is embedded, a second component releasing region (45) made of a first component and a second component, a solid electrolyte region (46) made of chalcogenide and an upper electrode region (47) are sequentially formed. The second component releasing region (45) made of a first component and a second component is composed of dome-shaped electrode portions (43) and an insulating film (44) burying the peripheries of the electrode portions (43), and at least one electrode portion (43) exists on the plug (34). The electrode portion (43) is composed of a first portion made of the first component such as tantalum oxide that is stable even when electric field is applied thereto and a second portion made of the second component such as copper or silver that is easily diffused in the solid electrolyte region (42) and moves therein by the application of an electric field.
    Type: Application
    Filed: February 9, 2006
    Publication date: February 12, 2009
    Inventors: Motoyasu Terao, Kenzo Kurotsuchi, Riichiro Takemura, Norikatsu Takaura, Satoru Hanzawa
  • Publication number: 20090039336
    Abstract: The performance of a semiconductor device capable of storing information is improved. A memory layer of a memory element is formed by a first layer at a bottom electrode side and a second layer at a top electrode side. The first layer contains 20-70 atom % of at least one element of a first element group of Cu, Ag, Au, Al, Zn, and Cd, contains 3-40 atom % of at least one element of a second element group of V, Nb, Ta, Cr, Mo, W, Ti, Zr, Hf, Fe, Co, Ni, Pt, Pd, Rh, Ir, Ru, Os, and lanthanoid elements, and contains 20-60 atom % of at least one element of a third element group of S, Se, and Te. The second layer contains 5-50 atom % of at least one element of the first element group, 10-50 atom % of at least one element of the second element group, and 30-70 atom % of oxygen.
    Type: Application
    Filed: July 21, 2008
    Publication date: February 12, 2009
    Inventors: Motoyasu Terao, Yoshitaka Sasago, Kenzo Kurotsuchi, Kazuo Ono, Yoshihisa Fujisaki, Norikatsu Takaura, Riichiro Takemura
  • Patent number: 7489588
    Abstract: A column circuit that amplifies signals read from a sense amplifier array SAA to local input/output lines LIO in sub-amplifiers SAMP to transfer the amplified signals to main input/output lines MIO is provided. A current control circuit IC that can set one of two kinds of currents according to read enable signals RD1, RD2 is provided in each sub-amplifier SAMP. The read enable signals RD1, RD2 are generated at timings corresponding to the number of cycles in burst read operation under control of the timing controller. Current in the current control circuit IC is set to be large by the RD1 in burst read operation cycle just after activation of a memory bank, while current in the current control circuit IC is set to be small by the RD2 in the next and subsequent burst read cycles. Accordingly, expansion of an operation margin or reduction of power consumption can be realized in a semiconductor device including a semiconductor memory such as a DRAM.
    Type: Grant
    Filed: October 25, 2007
    Date of Patent: February 10, 2009
    Assignees: Hitachi, Ltd., Elpida Memory, Inc.
    Inventors: Satoru Hanzawa, Tomonori Sekiguchi, Riichiro Takemura, Satoru Akiyama, Kazuhiko Kajigaya
  • Patent number: 7489552
    Abstract: In a non-volatile phase change memory, information is recorded by utilizing a change in resistance of a phase change portion. When the phase change portion is allowed to generate Joule's heat and is held at a specific temperature, it goes into a state of a low resistance. When the gate voltage of a memory cell selection transistor QM is controlled to afford a low resistance state, the maximum amount of current applied to the phase change portion is limited by the application of a medium-state voltage to the control gate, thereby avoiding overheating of the phase change portion.
    Type: Grant
    Filed: August 9, 2006
    Date of Patent: February 10, 2009
    Assignee: Renesas Technology Corp.
    Inventors: Kenzo Kurotsuchi, Norikatsu Takaura, Osamu Tonomura, Motoyasu Terao, Hideyuki Matsuoka, Riichiro Takemura
  • Publication number: 20090014770
    Abstract: A technique that can realize high integration even for multilayered three-dimensional structures at low costs by improving the performance of the semiconductor device having recording or switching functions by employing a device structure that enables high precision controlling of the movement of ions in the solid electrolyte. The semiconductor element of the device is formed as follows; two or more layers are deposited with different components respectively between a pair of electrodes disposed separately in the vertical (z-axis) direction, then a pulse voltage is applied between those electrodes to form a conductive path. The resistance value of the path changes according to an information signal. Furthermore, a region is formed at a middle part of the conductive path. The region is used to accumulate a component that improves the conductivity of the path, thereby enabling the resistance value (rate) to response currently to the information signal.
    Type: Application
    Filed: July 9, 2008
    Publication date: January 15, 2009
    Inventors: Motoyasu Terao, Hideyuki Matsuoka, Naohiko Irie, Yoshitaka Sasago, Riichiro Takemura, Norikatsu Takaura
  • Patent number: 7474550
    Abstract: A semiconductor memory includes a plurality of first regions arranged along a first direction, each of which corresponds to a memory array including a plurality of word lines, bit lines and memory cells. A plurality of second regions are provided each of which is arranged alternately with respect to each of the first regions, and each including sense amplifiers connected to said bit lines to form an open line type semiconductor memory. A third region is also provided that is a region not sandwiched by the second regions, wherein the third region includes a plurality of dummy bit lines.
    Type: Grant
    Filed: April 27, 2007
    Date of Patent: January 6, 2009
    Assignee: Elpida Memory, Inc.
    Inventors: Hiroki Fujisawa, Riichiro Takemura, Koji Arai
  • Publication number: 20090003105
    Abstract: A high-speed and low-voltage DRAM memory cell capable of operating at 1 V or less and an array peripheral circuit are provided. A DRAM cell is comprised of a memory cell transistor and planar capacitor which utilize a FD-SOI MOST structure. Since there is no junction leakage current, loss of stored charge is eliminated, and the low-voltage operation can be realized. Further, a gate and a well in a cross-coupled type sense amplifier using FD-SOI MOSTs are connected. By this means, a threshold value dynamically changes and high-speed sensing operation can be realized.
    Type: Application
    Filed: June 26, 2007
    Publication date: January 1, 2009
    Inventors: Kiyoo ITOH, Riichiro Takemura
  • Patent number: 7468901
    Abstract: In a two-transistor gain cell structure, a semiconductor memory device capable of stable reading without malfunction and having small-area memory cells is provided. In a two-transistor gain cell memory having a write transistor and a read transistor, a write word line, a read word line, a write bit line, and a read bit line are separately provided, and voltages to be applied are independently set. Furthermore, a memory cell is connected to the same read word line and write bit line as those of an adjacent memory cell.
    Type: Grant
    Filed: April 7, 2006
    Date of Patent: December 23, 2008
    Assignee: Renesas Technology Corp.
    Inventors: Norifumi Kameshiro, Riichiro Takemura, Tomoyuki Ishii
  • Publication number: 20080285325
    Abstract: In a two-transistor gain cell structure, a semiconductor memory device capable of stable reading without malfunction and having small-area memory cells is provided. In a two-transistor gain cell memory having a write transistor and a read transistor, a write word line, a read word line, a write bit line, and a read bit line are separately provided, and voltages to be applied are independently set. Furthermore, a memory cell is connected to the same read word line and write bit line as those of an adjacent memory cell.
    Type: Application
    Filed: August 5, 2008
    Publication date: November 20, 2008
    Inventors: NORIFUMI KAMESHIRO, Riichiro Takemura, Tomoyuki Ishii