Patents by Inventor Kazutami Arimoto

Kazutami Arimoto 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: 20040085844
    Abstract: In a Vss precharge scheme, a dummy cell including a bit line contact, a storage node contact and a third contact connected to a Vccs power supply line is arranged in complementary bit lines respectively. In a waiting state, H level data is written in each dummy cell from the Vccs power supply line. Before row active is started and a normal word line is selected, a dummy word line is driven to a selected state, and the H level data is read from each dummy cell. Therefore, charges of the same amount are injected to the complementary bit lines, and a shift from a Vss level to the same potential occurs. A sense amplifier uses the potential as a reference voltage to amplify and detect a potential difference between bit lines.
    Type: Application
    Filed: April 1, 2003
    Publication date: May 6, 2004
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazutami Arimoto, Hiroki Shimano
  • Patent number: 6649984
    Abstract: In a memory circuit, a transistor formed in the same process as that of a logic transistor is used for peripheral circuitry except for a region to be supplied with high voltage. Thus, the manufacturing process can be simplified and a logic-merged memory operating at a high speed is provided.
    Type: Grant
    Filed: August 3, 2000
    Date of Patent: November 18, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hideyuki Noda, Kazutami Arimoto, Katsumi Dosaka, Takeshi Fujino
  • Publication number: 20030206463
    Abstract: A memory cell unit includes a first storage element and a second storage element for storing complementary data with each other. In a selected state, the first and second storage elements are connected to complementary bit lines, respectively at a time. In a standby state, the bit lines are precharged to a voltage (Vccs or GND) corresponding to the data stored in the memory cell unit. Refresh-free, low-current-consumption semiconductor memory device operating stably even under a low power supply voltage can be implemented.
    Type: Application
    Filed: May 14, 2003
    Publication date: November 6, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Takeshi Fujino, Kazutami Arimoto, Hiroki Shimano
  • Patent number: 6643208
    Abstract: A variable impedance power supply line and a variable impedance ground line supplying voltages VCL1 and VSL1, respectively, are set to a low impedance state in a stand-by cycle and in a row related signal set period, and to a high impedance state in a column circuitry valid time period. Variable impedance power supply line and variable impedance ground line supplying voltages VCL2 and VSL2, respectively, are set to a high impedance state in the stand-by cycle, and low impedance state in the active cycle and in the row related signal reset time period. Inverters operate as operating power supply voltage of voltages VCL1 and VSL2 or voltages VCL2 and VSL1, in access with a logic level of an output signal in the stand-by cycle and in the active cycle. Thus a semiconductor memory device is provided in which subthreshold current in the stand-by cycle and active DC current in the active cycle can be reduced.
    Type: Grant
    Filed: January 21, 2003
    Date of Patent: November 4, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tadato Yamagata, Kazutami Arimoto, Masaki Tsukude
  • Patent number: 6636454
    Abstract: A memory cell unit includes a first storage element and a second storage element for storing complementary data with each other. In a selected state, the first and second storage elements are connected to complementary bit lines, respectively at a time. In a standby state, the bit lines are precharged to a voltage (Vccs or GND) corresponding to the data stored in the memory cell unit. Refresh-free, low-current-consumption semiconductor memory device operating stably even under a low power supply voltage can be implemented.
    Type: Grant
    Filed: January 9, 2001
    Date of Patent: October 21, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Fujino, Kazutami Arimoto, Hiroki Shimano
  • Publication number: 20030189869
    Abstract: A variable impedance power supply line and a variable impedance ground line supplying voltages VCL1 and VSL1, respectively, are set to a low impedance state in a stand-by cycle and in a row related signal set period, and to a high impedance state in a column circuitry valid time period. Variable impedance power supply line and variable impedance ground line supplying voltages VCL2 and VSL2, respectively, are set to a high impedance state in the stand-by cycle, and low impedance state in the active cycle and in the row related signal reset time period. Inverters operate as operating power supply voltage of voltages VCL1 and VSL2 or voltages VCL2 and VSL1, in accordance with a logic level of, an output signal in the stand-by cycle and in the active cycle. Thus a semiconductor memory device is provided in which subthreshold current in the stand-by cycle and active DC current in the active cycle can be reduced.
    Type: Application
    Filed: January 21, 2003
    Publication date: October 9, 2003
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tadato Yamagata, Kazutami Arimoto, Masaki Tsukude
  • Patent number: 6608795
    Abstract: When a row active command ACT_CMD is externally input, an internal clock control circuit activates a signal int.CKE, so that an external clock signal ext.CLK is responsively supplied to an internal memory array as signal int.CLK. Thus, clock control is meticulously conducted, whereby a system LSI with reduced current consumption in the memory array can be realized.
    Type: Grant
    Filed: October 23, 2002
    Date of Patent: August 19, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazutami Arimoto, Hiroki Shimano
  • Publication number: 20030137892
    Abstract: Memory cells are arranged such that one-bit data is stored by two-bit memory cells. The cell plate electrode of the memory cell capacitor and the gate electrode of the memory cell transistor are formed in the same manufacturing step. The amplitude of an isolation control signal applied to a bit line isolation gate connecting the bit line and the sense amplifier is restricted, and the word line is driven according to a negative voltage non-boosted word line scheme. A well region where a memory block is formed and a well region where the isolation gate is formed are separately provided, and separate bias voltages are applied thereto. Thus, a DRAM (dynamic random access memory)-based logic merged memory is implemented without degrading dielectric breakdown characteristics of the gate insulating film.
    Type: Application
    Filed: October 22, 2002
    Publication date: July 24, 2003
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazutami Arimoto, Hiroki Shimano
  • Patent number: 6597599
    Abstract: In a semiconductor memory in which memory cells where a bit line is connected with the impurity diffused area of MOS transistors are arranged in a close packed layout in order to reduce the gate capacitance and junction capacitance of the impurity diffused area of the MOS transistor, the width W1 of the active region of the MOS transistor of field pattern FL constituting the memory cell is formed narrower than the width W2 of the active region of the capacitor.
    Type: Grant
    Filed: July 5, 2002
    Date of Patent: July 22, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Toshinori Morihara, Hiroki Shimano, Katsumi Dosaka, Kazutami Arimoto
  • Publication number: 20030103368
    Abstract: In a data holding mode, data storage in a one bit/one cell scheme in a normal operating mode are rearranged into data storage in a twin-cell mode in which data are stored in a one bit/two cell scheme. In the twin-cell mode, two sub word lines are simultaneously driven into a selected state, and storage data of memory cells are read out on both of bit lines in a pair, to perform a sense operation. Thus, the read-out voltage can be increased to improve the data retention characteristics for lengthening a refresh interval, resulting in a reduced power consumption in the data holding mode.
    Type: Application
    Filed: August 28, 2002
    Publication date: June 5, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Kazutami Arimoto, Hiroki Shimano, Takeshi Fujino, Takeshi Hashizume
  • Patent number: 6573613
    Abstract: A word line and a cell plate electrode line are formed at a common interconnection layer. A redundant replacement unit for a faulty row is set corresponding to the cell plate electrode line. For each redundant replacement unit, a program element is arranged for stopping supply of a cell plate voltage from the cell plate voltage line to the cell plate electrode line. The program element corresponding to the cell plate electrode line short-circuited to the word line nonvolatilely changes from the on state to the off state in response to an externally supplied input instruction.
    Type: Grant
    Filed: April 9, 2002
    Date of Patent: June 3, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazutami Arimoto, Hiroki Shimano
  • Publication number: 20030039160
    Abstract: When a row active command ACT_CMD is externally input, an internal clock control circuit activates a signal int.CKE, so that an external clock signal ext.CLK is responsively supplied to an internal memory array as signal int.CLK. Thus, clock control is meticulously conducted, whereby a system LSI with reduced current consumption in the memory array can be realized.
    Type: Application
    Filed: October 23, 2002
    Publication date: February 27, 2003
    Applicant: MITSUBISHI DENKI KABUSHIKI KAISHA
    Inventors: Kazutami Arimoto, Hiroki Shimano
  • Patent number: 6525984
    Abstract: A variable impedance power supply line and a variable impedance ground line supplying voltages VCL1 and VSL1, respectively, are set to a low impedance state in a stand-by cycle and in a row related signal set period, and to a high impedance state in a column circuitry valid time period. Variable impedance power supply line and variable impedance ground line supplying voltages VCL2 and VSL2, respectively, are set to a high impedance state in the stand-by cycle, and low impedance state in the active cycle and in the row related signal reset time period. Inverters operate as operating power supply voltage of voltages VCL1 and VSL2 or voltages VCL2 and VSL1, in accordance with a logic level of an output signal in the stand-by cycle and in the active cycle. Thus a semiconductor memory device is provided in which subthreshold current in the stand-by cycle and active DC current in the active cycle can be reduced.
    Type: Grant
    Filed: January 17, 2002
    Date of Patent: February 25, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tadato Yamagata, Kazutami Arimoto, Masaki Tsukude
  • Publication number: 20030021140
    Abstract: In a semiconductor memory in which memory cells where a bit line is connected with the impurity diffused area of MOS transistors are arranged in a close packed layout in order to reduce the gate capacitance and junction capacitance of the impurity diffused area of the MOS transistor, the width W1 of the active region of the MOS transistor of field pattern FL constituting the memory cell is formed narrower than the width W2 of the active region of the capacitor.
    Type: Application
    Filed: July 5, 2002
    Publication date: January 30, 2003
    Inventors: Toshinori Morihara, Hiroki Shimano, Katsumi Dosaka, Kazutami Arimoto
  • Publication number: 20030015735
    Abstract: A word line and a cell plate electrode line are formed at a common interconnection layer. A redundant replacement unit for a faulty row is set corresponding to the cell plate electrode line. For each redundant replacement unit, a program element is arranged for stopping supply of a cell plate voltage from the cell plate voltage line to the cell plate electrode line. The program element corresponding to the cell plate electrode line short-circuited to the word line nonvolatilely changes from the on state to the off state in response to an externally supplied input instruction.
    Type: Application
    Filed: April 9, 2002
    Publication date: January 23, 2003
    Applicant: Mitsubishi Denki Dabushiki Kaisha
    Inventors: Kazutami Arimoto, Hiroki Shimano
  • Patent number: 6507532
    Abstract: A central row-related control circuit transmits an internal row address signal to each memory sub block in banks of memory mats asynchronously with an external clock signal, and latches a block selection signal for specifying a memory sub block synchronously with an internal clock signal for one clock cycle period for transmission to each memory sub block. A spare determination circuit performs spare determination asynchronously with the clock signal. A semiconductor memory device easily adaptable to bank expansion without increase of the chip area and capable of implementing a high speed access can be provided.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: January 14, 2003
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Takeshi Fujino, Kazunari Inoue, Akira Yamazaki, Kazutami Arimoto
  • Publication number: 20020195669
    Abstract: There is provided a semiconductor integrated circuit device comprising: a field placement creating a field pattern in an array form by closest packing on a first conductance-type semiconductor substrate, the field pattern including a plurality of memory cells which define an active area and a device isolation region of a field effect transistor, and which are arranged in a predetermined pitch in the longitudinal and transverse directions, respectively, each memory cell having a pattern of a certain length-to-width size; a cell plate placement providing a capacitor structure between a second conductance-type diffusion region formed by an impurity implant to the active area and a cell plate electrode formed so as to cover part of the active area with a predetermined cell plate pattern through a capacitor dielectric, the cell plate pattern extending in the transverse direction with a certain length size; and a word line placement in which a word line pattern is arranged in the transverse direction of a vacant zo
    Type: Application
    Filed: August 16, 2002
    Publication date: December 26, 2002
    Inventors: Toshinori Morihara, Hiroki Shimano, Kazutami Arimoto
  • Patent number: 6498396
    Abstract: An external interconnection unit including a pad provided on a semiconductor chip, a bump electrode formed on a main surface of a semiconductor chip for connection with the board, and a connection interconnection for connecting the pad and the bump electrode is provided in a plurality of stages in two rows in parallel. The bump electrode is provided on a region other than the region of a sense amplifier region (SR). A semiconductor package having reliability as a semiconductor device prevented from being degraded, and a semiconductor package effectively taking advantage of the feature of a CSP structure is provided.
    Type: Grant
    Filed: March 28, 1996
    Date of Patent: December 24, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Kazutami Arimoto
  • Patent number: 6486493
    Abstract: A plurality of test interface circuits are disposed in correspondence with a plurality of DRAM cores. An upper test interface circuit transmits a test control signal or the like supplied from the outside to each of or one of the plurality of test interface circuits in accordance with a memory core selection signal. When all of the DRAM cores are designated as targets of an operation test, test output data from the DRAM cores is compared with each other by a data comparing circuit and is outputted as judge flag data reflecting the result of the comparison to the outside.
    Type: Grant
    Filed: August 31, 2001
    Date of Patent: November 26, 2002
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazutami Arimoto, Hiroki Shimano
  • Publication number: 20020172070
    Abstract: Conductive lines constituting word lines of memory cells and conductive lines constituting memory cell plate electrodes are formed in the same interconnecting layer in a memory device including a plurality of memory cells each including a capacitor for storing data in an electrical charge form. By forming the capacitors of the memory cells into a planar capacitor configuration, a step due to the capacitors is removed. Thus. a dynamic semiconductor memory device can be formed through CMOS process, and a dynamic semiconductor memory device suitable for merging with logic is achieved. Data of 1 bit is stored by two memory cells, and data can be reliably stored even if the capacitance value of the memory cell is reduced due to the planar type capacitor.
    Type: Application
    Filed: April 10, 2002
    Publication date: November 21, 2002
    Applicant: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Kazutami Arimoto, Hiroki Shimano