Patents by Inventor Kiyoo Itoh

Kiyoo Itoh 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).

  • Patent number: 7242214
    Abstract: Power dissipation of a semiconductor integrated circuit chip is reduced when it is operated at an operating voltage of 2.5 V or below. A switching element is provided in each circuit block within the chip. Constants of the switching element are set so that leakage current in each switching element in their off-state is smaller than the subthreshold current of MOS transistors within the corresponding circuit block. Active current is supplied to active circuit blocks, while switching elements of non-active circuit blocks are turned off. Thus, dissipation currents of non-active circuit blocks are limited to leakage current value of corresponding switching elements. Thus, the sum of dissipation currents of non-active circuit blocks is made smaller than the active current in the active circuit blocks. As a result, power dissipation in the semiconductor integrated circuit chip can be reduced even in the active state.
    Type: Grant
    Filed: November 15, 2006
    Date of Patent: July 10, 2007
    Assignee: Elpida Memory, Inc.
    Inventors: Takeshi Sakata, Kiyoo Itoh, Masashi Horiguchi
  • Publication number: 20070152736
    Abstract: A CMOS circuit in low-voltage implementation, low power-consumption implementation, high-speed implementation, or small-size implementation. In a circuit which uses a FD-SOI MOST where a back gate is controlled by a well, voltage amplitude at the well is made larger than input-voltage amplitude at the gate. Alternatively, the circuit is modified into a circuit which uses a MOST that changes dynamically into an enhancement mode and a depletion mode.
    Type: Application
    Filed: March 7, 2007
    Publication date: July 5, 2007
    Inventors: Kiyoo Itoh, Ryuta Tsuchiya, Takayuki Kawahara
  • Patent number: 7230867
    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: Grant
    Filed: August 18, 2005
    Date of Patent: June 12, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Riichiro Takemura, Kiyoo Itoh, Tomonori Sekiguchi, Takeshi Sakata, Katsutaka Kimura
  • Publication number: 20070109034
    Abstract: The well voltage of a CMOS circuit having low-threshold-voltage MOSFETs is controlled when the power supply is turned on, during normal operation, and when the supply voltage is cut off. The CMOS circuit can thus operate stably with lower power consumption, because latching-up is reduced when the supply voltage is applied to the CMOS circuit or when the supply voltage is cut off, and subthreshold current is decreased during normal operation.
    Type: Application
    Filed: January 5, 2007
    Publication date: May 17, 2007
    Inventors: Kiyoo Itoh, Hiroyuki Mizuno
  • Patent number: 7215136
    Abstract: Power dissipation of a semiconductor integrated circuit chip is reduced when it is operated at an operating voltage of 2.5 V or below. A switching element is provided in each circuit block within the chip. Constants of the switching element are set so that leakage current in each switching element in their off-state is smaller than the subthreshold current of MOS transistors within the corresponding circuit block. Active current is supplied to active circuit blocks, while switching elements of non-active circuit blocks are turned off. Thus, dissipation currents of non-active circuit blocks are limited to leakage current value of corresponding switching elements. Thus, the sum of dissipation currents of non-active circuit blocks is made smaller than the active current in the active circuit blocks. As a result, power dissipation in the semiconductor integrated circuit chip can be reduced even in the active state.
    Type: Grant
    Filed: February 17, 2006
    Date of Patent: May 8, 2007
    Assignee: Elpida Memory, Inc.
    Inventors: Takeshi Sakata, Kiyoo Itoh, Masashi Horiguchi
  • Patent number: 7196368
    Abstract: A capacitor consisting of a storage electrode (19), a capacitor dielectric film (20) and a plate electrode (21) is formed in a trench formed through dielectric films (6, 8, 10 and 12) stacked on a semiconductor substrate (1) and buried wiring layers (9 and 11) are formed under the capacitor. As the capacitor is formed not in the semiconductor substrate but over it, there is room in area in which the capacitor can be formed and the difficultly of forming wiring is reduced by using the wiring layers (9 and 11) for a global word line and a selector line. As the upper face of an dielectric film (32) which is in contact with the lower face of wiring (34) in a peripheral circuit area is extended into a memory cell area and is in contact with the side of the capacitor (33), step height between the peripheral circuit area and the memory cell area is remarkably reduced.
    Type: Grant
    Filed: August 10, 2004
    Date of Patent: March 27, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Shinichiro Kimura, Toshiaki Yamanaka, Kiyoo Itoh, Takeshi Sakata, Tomonori Sekiguchi, Hideyuki Matsuoka
  • Publication number: 20070057696
    Abstract: Power dissipation of a semiconductor integrated circuit chip is reduced when it is operated at an operating voltage of 2.5 V or below. A switching element is provided in each circuit block within the chip. Constants of the switching element are set so that leakage current in each switching element in their off-state is smaller than the subthreshold current of MOS transistors within the corresponding circuit block. Active current is supplied to active circuit blocks, while switching-elements of non-active circuit blocks are turned off. Thus, dissipation currents of non-active circuit blocks are limited to leakage current value of corresponding switching elements. Thus, the sum of dissipation currents of non-active circuit blocks is made smaller than the active current in the active circuit blocks. As a result, power dissipation in the semiconductor integrated circuit chip can be reduced even in the active state.
    Type: Application
    Filed: November 15, 2006
    Publication date: March 15, 2007
    Inventors: Takeshi Sakata, Kiyoo Itoh, Masashi Horiguchi
  • Patent number: 7176745
    Abstract: The well voltage of a CMOS circuit having low-threshold-voltage MOSFETs is controlled when the power supply is turned on, during normal operation, and when the supply voltage is cut off. The CMOS circuit can thus operate stably with lower power consumption, because latching-up is reduced when the supply voltage is applied to the CMOS circuit or when the supply voltage is cut off, and subthreshold current is decreased during normal operation.
    Type: Grant
    Filed: May 24, 2004
    Date of Patent: February 13, 2007
    Assignee: Renesas Technology Corp.
    Inventors: Kiyoo Itoh, Hiroyuki Mizuno
  • Publication number: 20070008027
    Abstract: A CMOS circuit in low-voltage implementation, low power-consumption implementation, high-speed implementation, or small-size implementation. In a circuit which uses a FD-SOI MOST where a back gate is controlled by a well, voltage amplitude at the well is made larger than input-voltage amplitude at the gate. Alternatively, the circuit is modified into a circuit which uses a MOST that changes dynamically into an enhancement mode and a depletion mode.
    Type: Application
    Filed: February 27, 2006
    Publication date: January 11, 2007
    Inventors: Kiyoo Itoh, Ryuta Tsuchiya, Takayuki Kawahara
  • Publication number: 20060280010
    Abstract: The object of the invention is to avoid an unselected data line being driven in a memory array composed of memory cells each of which uses a storage element depending upon variable resistance and a selection transistor when the selection transistors in all memory cells on a selected word line conduct. To achieve the object, a source line parallel to a data line is provided, a precharge circuit for equipotentially driving both and a circuit for selectively driving the source line are arranged. Owing to this configuration, a current path is created in only a cell selected by a row decoder and a column decoder and a read-out signal can be generated. Therefore, a lower-power, lower-noise and more highly integrated nonvolatile memory such as a phase change memory can be realized, compared with a conventional type.
    Type: Application
    Filed: August 22, 2006
    Publication date: December 14, 2006
    Inventors: Satoru Hanzawa, Kiyoo Itoh, Hideyuki Matsuoka, Motoyasu Terao, Takeshi Sakata
  • Patent number: 7145383
    Abstract: As the chip manufacturing process progresses towards making smaller and finer chip circuitry, leakage currents of different types including the subthreshold leakage current, gate tunneling leakage current and GIDL (Gate-Induced Drain Leakage) current increase. These leakage currents increase the electrical current consumption of the chip. In a semiconductor integrated circuit device comprising a circuit block having a first MOS transistor, and a leakage current control circuit having a second MOS transistor and a current source, a source and drain circuit of the second MOS transistor is formed between the power supply line of the circuit block and a voltage point where operating voltage is supplied.
    Type: Grant
    Filed: August 24, 2004
    Date of Patent: December 5, 2006
    Assignee: Renesas Technology Corporation
    Inventors: Hiroyuki Mizuno, Kiyoo Itoh
  • Publication number: 20060267676
    Abstract: In a semiconductor integrated circuit device, a circuit block has a first MOS transistor, and a leakage current control circuit having a second MOS transistor and a current source, a source and drain circuit of the second MOS transistor is formed between the power supply line of the circuit block and a voltage point where operating voltage is supplied. This current source is connected to the power supply line and in a first state, the power supply line is driven to a first voltage by the second MOS transistor. In a second state, the power supply line is controlled at a second voltage by current flow in the current source and, the voltage applied across the source and drain of the first MOS transistor in the second state is smaller than the voltage applied across the source and drain of the first MOS transistor in the first state.
    Type: Application
    Filed: July 27, 2006
    Publication date: November 30, 2006
    Inventors: Hiroyuki Mizuno, Kiyoo Itoh
  • Patent number: 7132713
    Abstract: A controllable conduction device in the form of a transistor comprises source and drain regions 5, 2 between which extends a conduction path P for charge carriers, a gate 4 for controlling charge carrier flow along the conduction path and a multiple layer structure 3 providing a multiple tunnel junction configuration in the conduction path, with the result that current leakage is blocked by the multiple tunnel junction configuration when the transistor is in its off state. Vertical and lateral transistor configurations are described, together with use of the transistor in complimentary pairs and for a random access memory cell. Improved gate structures are described which are also applicable to memory devices that incorporate the tunnel barrier configuration to store charge on the memory node.
    Type: Grant
    Filed: April 15, 2002
    Date of Patent: November 7, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Kazuo Nakazato, Kiyoo Itoh, Hiroshi Mizuta, Toshikazu Shimada, Hideo Sunami, Tatsuya Teshima, Toshiyuki Mine, Ken Yamaguchi
  • Patent number: 7116593
    Abstract: The object of the invention is to avoid an unselected data line being driven in a memory array composed of memory cells each of which uses a storage element depending upon variable resistance and a selection transistor when the selection transistors in all memory cells on a selected word line conduct. To achieve the object, a source line parallel to a data line is provided, a precharge circuit for equipotentially driving both and a circuit for selectively driving the source line are arranged. Owing to this configuration, a current path is created in only a cell selected by a row decoder and a column decoder and a read-out signal can be generated. Therefore, a lower-power, lower-noise and more highly integrated nonvolatile memory such as a phase change memory can be realized, compared with a conventional type.
    Type: Grant
    Filed: September 13, 2002
    Date of Patent: October 3, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Satoru Hanzawa, Kiyoo Itoh, Hideyuki Matsuoka, Motoyasu Terao, Takeshi Sakata
  • Publication number: 20060203542
    Abstract: A semiconductor non volatile memory device capable of multiple write operations with high reliability is implemented. The memory device includes memory cells, each comprising a first electrode, a second electrode, and an information storage section put between the two electrodes, wherein an operation to feed a first pulse current from the first electrode to the second, and another operation to feed a second pulse current from the second electrode to the first. A segregation of composing elements of the information storage section is caused by applying the first pulse, however, the segregation of elements is resolved by applying the second pulse, and the composition of the element recovers to the original state.
    Type: Application
    Filed: January 30, 2006
    Publication date: September 14, 2006
    Inventors: Kenzo Kurotsuchi, Kiyoo Itoh, Norikatsu Takaura, Kenichi Osada
  • Patent number: 7106643
    Abstract: Method for manufacturing a memory device, the memory being a memory array with a spare bit line and being provided with a defect recovery scheme featuring a redundancy circuit. The redundancy circuit includes one or more comparing circuits having programmable elements which function as a memory for storing therein a defective address existing in the memory array. The programmable elements of the redundancy circuit can be programmed in accordance with any of a number of different types of defect modes. Each comparing circuit of the redundancy circuit compares information (data) inputted therein, for example, the column and row addresses which may be under the control of an address multiplex system, with that programmed in the programmable elements of the comparing circuit. On the basis of this comparison, an appropriate defect recovery is effected.
    Type: Grant
    Filed: May 31, 2005
    Date of Patent: September 12, 2006
    Assignee: Renesas Technology Corp.
    Inventors: Masashi Horiguchi, Jun Etoh, Masakazu Aoki, Kiyoo Itoh
  • Patent number: 7078273
    Abstract: A semiconductor memory cell and forming method thereof utilizes a vertical select transistor to eliminate the problem of a large cell surface area in memory cells of the related art utilizing phase changes. A memory cell with a smaller surface area than the DRAM device of the related art is achieved by the present invention. Besides low power consumption during read operation, the invention also provides phase change memory having low power consumption even during write operation. Phase change memory also has stable read-out operation.
    Type: Grant
    Filed: June 28, 2004
    Date of Patent: July 18, 2006
    Assignee: Hitachi, Ltd.
    Inventors: Hideyuki Matsuoka, Kiyoo Itoh, Motoyasu Terao, Satoru Hanzawa, Takeshi Sakata
  • Publication number: 20060148135
    Abstract: A semiconductor memory cell and forming method thereof utilizes a vertical select transistor to eliminate the problem of a large cell surface area in memory cells of the related art utilizing phase changes. A memory cell with a smaller surface area than the DRAM device of the related art is achieved by the present invention. Besides low power consumption during read operation, the invention also provides phase change memory having low power consumption even during write operation. Phase change memory also has stable read-out operation.
    Type: Application
    Filed: March 7, 2006
    Publication date: July 6, 2006
    Inventors: Hideyuki Matsuoka, Kiyoo Itoh, Motoyasu Terao, Satoru Hanzawa, Takeshi Sakata
  • Publication number: 20060139052
    Abstract: Power dissipation of a semiconductor integrated circuit chip is reduced when it is operated at an operating voltage of 2.5 V or below. A switching element is provided in each circuit block within the chip. Constants of the switching element are set so that leakage current in each switching element in their off-state is smaller than the subthreshold current of MOS transistors within the corresponding circuit block. Active current is supplied to active circuit blocks, while switching elements of non-active circuit blocks are turned off. Thus, dissipation currents of non-active circuit blocks are limited to leakage current value of corresponding switching elements. Thus, the sum of dissipation currents of non-active circuit blocks is made smaller than the active current in the active circuit blocks. As a result, power dissipation in the semiconductor integrated circuit chip can be reduced even in the active state.
    Type: Application
    Filed: February 17, 2006
    Publication date: June 29, 2006
    Inventors: Takeshi Sakata, Kiyoo Itoh, Masashi Horiguchi
  • Patent number: 7043466
    Abstract: The neural network processing system according to the present invention includes a memory circuit for storing neuron output values, connection weights, the desired values of outputs, and data necessary for learning; an input/output circuit for writing or reading data in or out of said memory circuit; a processing circuit for performing a processing for determining the neuron outputs such as the product, sum and nonlinear conversion of the data stored in said memory circuit, a comparison of the output value and its desired value, and a processing necessary for learning; and a control circuit for controlling the operations of said memory circuit, said input/output circuit and said processing circuit.
    Type: Grant
    Filed: December 20, 2000
    Date of Patent: May 9, 2006
    Assignee: Renesas Technology Corp.
    Inventors: Takao Watanabe, Katsutaka Kimura, Kiyoo Itoh, Yoshiki Kawajiri