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).

  • Publication number: 20030012049
    Abstract: A static memory cell, composed of cross-coupled MOS transistors having a relatively high threshold voltage, is equipped with MOS transistors for controlling the power supply line voltage of the memory cell. To permit the voltage difference between two data storage nodes in the inactivated memory cell to exceed the voltage difference between the two nodes when write data is applied from a data line pair DL and /DL to the two nodes in the activated memory cell, the power supply line voltage control transistors are turned on to apply a high voltage VCH to the power supply lines after the word line voltage is turned off. The data holding voltage in the memory cell can be activated to a high voltage independent of the data line voltage, and the data holding voltage can be dynamically set so that read and write operations can be performed at high speed with low power consumption.
    Type: Application
    Filed: September 16, 2002
    Publication date: January 16, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Kiyoo Itoh, Koichiro Ishibashi
  • Patent number: 6504402
    Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with at least two MOS transistors. The logic gates are connected to a first potential point and a second potential point. The semiconductor integrated circuit device includes a current control device connected between the logic gate and the first potential point and/or between the logic gate and the second potential point for controlling a value of a current flowing in the logic gate depending on an operating state of the logic gate. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors that have both an operation mode and a low power back-up or sleep mode used for power reduction.
    Type: Grant
    Filed: January 22, 2002
    Date of Patent: January 7, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Masashi Horiguchi, Kunio Uchiyama, Kiyoo Itoh, Takeshi Sakata, Masakazu Aoki, Takayuki Kawahara
  • Patent number: 6498762
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Grant
    Filed: January 9, 2002
    Date of Patent: December 24, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Publication number: 20020192902
    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 difficulty of forming wiring is reduced by using the wiring layers (9 and 11) for a global word line and a selector line.
    Type: Application
    Filed: July 29, 2002
    Publication date: December 19, 2002
    Inventors: Shinichiro Kimura, Toshiaki Yamanaka, Kiyoo Itoh, Takeshi Sakata, Tomonori Sekiguchi, Hideyuki Matsuoka
  • Publication number: 20020192901
    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 difficulty of forming wiring is reduced by using the wiring layers (9 and 11) for a global word line and a selector line.
    Type: Application
    Filed: July 26, 2002
    Publication date: December 19, 2002
    Inventors: Shinichiro Kimura, Toshiaki Yamanaka, Kiyoo Itoh, Takeshi Sakata, Tomonori Sekiguchi, Hideyuki Matsuoka
  • Patent number: 6477100
    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 22, 2001
    Date of Patent: November 5, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Riichiro Takemura, Kiyoo Itoh, Tomonori Sekiguchi, Takeshi Sakata, Katsutaka Kimura
  • Patent number: 6473333
    Abstract: The present invention provides a circuit, in which a device typified by a PLED element is built into a flip-flop. In this case, a storage node of the device is low leakage. According to the present invention, it is possible to realize a SRAM that has nonvolatility while achieving high-speed operation. It is also possible to realize a flip-flop having the same characteristics. An example of a typical mode of the present invention is a storage circuit characterized by the following: a storage element is a device incorporating: a first path for a carrier; a first mode for storing a charge that generates an electric field where conductivity of the first path is changed; and a barrier structure through which a second carrier moves in response to given voltage so that the second carrier is stored in the first node; and the storage circuit includes a second node, to which information stored in the first node is outputted steadily in a state in which power is supplied.
    Type: Grant
    Filed: November 13, 2001
    Date of Patent: October 29, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Suguru Tachibana, Katsuro Sasaki, Kiyoo Itoh, Tomoyuki Ishii
  • Patent number: 6473354
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Grant
    Filed: January 9, 2002
    Date of Patent: October 29, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Publication number: 20020153591
    Abstract: Disclosed is a semiconductor device, such as a semiconductor memory device, having structure wherein invasion of minority carriers from the semiconductor substrate into components of the device, formed on the substrate, can be avoided. The semiconductor memory device can be an SRAM or DRAM, for example, and includes a memory array and peripheral circuit on a substrate. In one aspect of the present invention, a buried layer of the same conductivity type as that of the substrate, but with a higher impurity concentration than that of the substrate, is provided beneath at least one of the peripheral circuit and memory array. A further region can extend from the buried layer, for example, to the surface of the semiconductor substrate, the buried layer and further region in combination acting as a shield to prevent minority carriers from penetrating to the device elements.
    Type: Application
    Filed: April 4, 2002
    Publication date: October 24, 2002
    Inventors: Shinji Nakazato, Hideaki Uchida, Yoshikazu Saito, Masahiro Yamamura, Yutaka Kobayashi, Takahide Ikeda, Ryoichi Hori, Goro Kitsukawa, Kiyoo Itoh, Nobuo Tanba, Takao Watanabe, Katsuhiro Shimohigashi, Noriyuki Homma
  • Patent number: 6469950
    Abstract: A static memory cell, composed of cross-coupled MOS transistors having a relatively high threshold voltage, is equipped with MOS transistors for controlling the power supply line voltage of the memory cell. To permit the voltage difference between two data storage nodes in the inactivated memory cell to exceed the voltage difference between the two nodes when write data is applied from a data line pair DL and /DL to the two nodes in the activated memory cell, the power supply line voltage control transistors are turned on to apply a high voltage VCH to the power supply lines after the word line voltage is turned off. The data holding voltage in the memory cell can be activated to a high voltage independent of the data line voltage, and the data holding voltage can be dynamically set so that read and write operations can be performed at high speed with low power consumption.
    Type: Grant
    Filed: April 16, 2002
    Date of Patent: October 22, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Kiyoo Itoh, Koichiro Ishibashi
  • Publication number: 20020139973
    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: Application
    Filed: April 15, 2002
    Publication date: October 3, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Kazuo Nakazato, Kiyoo Itoh, Hiroshi Mizuta, Toshikazu Shimada, Hideo Sunami, Tatsuya Teshima, Toshiyuki Mine, Ken Yamaguchi
  • Publication number: 20020135397
    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: March 25, 2002
    Publication date: September 26, 2002
    Inventors: Takeshi Sakata, Kiyoo Itoh, Masashi Horiguchi
  • Publication number: 20020131314
    Abstract: A semiconductor integrated circuit comprises a semiconductor chip, a power supply terminal provided on the semiconductor chip for receiving a voltage from an external power supply source, an internal circuit provided on the semiconductor chip, a power supply circuit provided on the semiconductor chip for transforming an external power supply voltage received from the power supply terminal for supplying a source voltage resulting from the voltage transformation to the internal circuit, and a control circuit provided on the semiconductor chip for controlling the power supply circuit, wherein the control circuit includes external power supply voltage detecting means and/or temperature detecting means and responds to the signal from the external power supply voltage detecting means and/or the temperature detecting means by changing the power supply voltage to the internal circuit to thereby maintain the operating speed of the internal circuit to be constant
    Type: Application
    Filed: March 25, 2002
    Publication date: September 19, 2002
    Inventors: Takao Watanabe, Ryoichi Hori, Goro Kitsukawa, Yoshiki Kawajiri, Kawahara Takayuki, Kiyoo Itoh
  • Publication number: 20020110036
    Abstract: A static memory cell, composed of cross-coupled MOS transistors having a relatively high threshold voltage, is equipped with MOS transistors for controlling the power supply line voltage of the memory cell. To permit the voltage difference between two data storage nodes in the inactivated memory cell to exceed the voltage difference between the two nodes when write data is applied from a data line pair DL and /DL to the two nodes in the activated memory cell, the power supply line voltage control transistors are turned on to apply a high voltage VCH to the power supply lines after the word line voltage is turned off. The data holding voltage in the memory cell can be activated to a high voltage independent of the data line voltage, and the data holding voltage can be dynamically set so that read and write operations can be performed at high speed with low power consumption.
    Type: Application
    Filed: April 16, 2002
    Publication date: August 15, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Kiyoo Itoh, Koichiro Ishibashi
  • Patent number: 6424586
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Grant
    Filed: January 9, 2002
    Date of Patent: July 23, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata
  • Publication number: 20020093845
    Abstract: Since a memory cell of a so-called MRAM utilizing a conventional tunnel magnetic resistance forms writing word lines below data lines, there are the following problems. A process becomes hard because it is necessary to execute a self-aligned contact opening process with passing through portions between the writing word lines, or since it is hard that the writing word lines sufficiently overlap with a magnetic resistance device in a planner manner due to a restriction of layout, the data writing becomes unstable. In order to solve the problems mentioned above, the present invention provides a structure of MRAM memory cell in which the writing word lines are formed above the bit lines, and a method of manufacturing the same.
    Type: Application
    Filed: August 23, 2001
    Publication date: July 18, 2002
    Inventors: Hideyuki Matsuoka, Takeshi Sakata, Katsuro Watanabe, Kiyoo Itoh
  • Publication number: 20020084804
    Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with at least two MOS transistors. The logic gates are connected to a first potential point and a second potential point. The semiconductor integrated circuit device includes a current control device connected between the logic gate and the first potential point and/or between the logic gate and the second potential point for controlling a value of a current flowing in the logic gate depending on an operating state of the logic gate. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors that have both an operation mode and a low power back-up or sleep mode used for power reduction.
    Type: Application
    Filed: January 22, 2002
    Publication date: July 4, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Masashi Horiguchi, Kunio Uchiyama, Kiyoo Itoh, Takeshi Sakata, Masakazu Aoki, Takayuki Kawahara
  • Patent number: 6407420
    Abstract: According to the present invention, an overlay margin is secured for matching a wiring electrode 11 with a storage electrode 15 of a capacitor at their point of contact and the required area for a memory cell can be decreased by placing the plug electrode 11 of titanium nitride in the active region of a semiconductor substrate or over the gate electrode, reducing the size of the opening for passing the storage electrode 15 of the capacitor of a stacked structure, and decreasing the line width of a wiring electrode 13. By the common use of the above-mentioned plug electrodes in a CMISFET region in the peripheral circuit and in a memory cell of a static RAM, their circuit layouts can be made compact.
    Type: Grant
    Filed: June 17, 1999
    Date of Patent: June 18, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Toshiaki Yamanaka, Shin'ichiro Kimura, Hideyuki Matsuoka, Tomonori Sekiguchi, Takeshi Sakata, Kiyoo Itoh
  • Patent number: 6404239
    Abstract: A semiconductor integrated circuit device is composed of logic gates each provided with at least two MOS transistors. The logic gates are connected to a first potential point and a second potential point. The semiconductor integrated circuit device includes a current control device connected between the logic gate and the first potential point and/or between the logic gate and the second potential point for controlling a value of a current flowing in the logic gate depending on an operating state of the logic gate. The circuit can be used in devices that cycle in operation between high and low power consumption modes, such as microprocessors that have both an operation mode and a low power back-up or sleep mode used for power reduction.
    Type: Grant
    Filed: July 10, 2000
    Date of Patent: June 11, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Takayuki Kawahara, Ryoichi Hori, Masashi Horiguchi, Ryoichi Kurihara, Kiyoo Itoh, Masakazu Aoki, Takeshi Sakata, Kunio Uchiyama
  • Patent number: 6396761
    Abstract: A dynamic RAM is divided into an input circuit block responsive to an input signal supplied from an external terminal, inclusive of an operation start signal, an internal circuit block activated in response to the signal inputted from the input circuit block, and an output circuit block for outputting a signal outputted from the internal circuit block to an external terminal. A plurality of switch MOSFETs are provided in parallel form between a power line for applying an operating voltage supplied from an external terminal and an internal power line for a first circuit portion in the internal circuit block, which does not need a storage operation upon its non-operating state. Further, the switch MOSFETs are stepwise turned on in response to controls signals produced by delaying a start signal supplied through the input circuit block in turn, so as to perform the supply of each operating voltage.
    Type: Grant
    Filed: June 7, 2001
    Date of Patent: May 28, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Hiromasa Noda, Masakazu Aoki, Youji Idei, Kazuhiko Kajigaya, Osamu Nagashima, Kiyoo Itoh, Masashi Horiguchi, Takeshi Sakata