Patents by Inventor Hidenobu Minagawa

Hidenobu Minagawa 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: 6118699
    Abstract: That surface portion of a semiconductor substrate which is adjacent to a buried source region formed in the substrate is covered with an offset side wall to suppress expansion of a channel beneath the offset side wall. In addition, buried source regions in the form of offset side walls are formed on the two sides of a drain region having one non-offset side wall to prevent a write or read error in unselected memory cell transistors on both sides of a selected memory transistor either in a data write or in a data read.
    Type: Grant
    Filed: July 13, 1999
    Date of Patent: September 12, 2000
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuichi Tatsumi, Noriaki Suzuki, Hidenobu Minagawa, Kazuhiko Satou, Hitoshi Ohta
  • Patent number: 5175704
    Abstract: In a nonvolatile semiconductor memory device, a wiring layer is connected between a power source and a memory cell. Resistance of the wiring layer is larger than the on-resistance of a load transistor, so that the load transistor substantially determines the load characteristic. Therefore, the load characteristic curve is more gentle in inclination and more rectilinear in shape. This makes the data writing operation stable against a variance in the channel lengths of manufactured transistors forming the memory cells.
    Type: Grant
    Filed: October 31, 1990
    Date of Patent: December 29, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hidenobu Minagawa, Yuuichi Tatsumi, Hiroshi Iwahashi, Masamichi Asano, Hiroto Nakai, Mizuho Imai
  • Patent number: 5138579
    Abstract: A semiconductor memory device includes word lines selectively driven by a signal from a row decoder, memory cells connected to word lines, first and second data lines, a bit line connected to receive data from the memory cell and to supply received data to the first data lines, dummy cells connected to word lines, first and second dummy data lines, a dummy bit lines connected to receive data from the dummy memory cell and to supply received data to the first dummy data line, a data sensing circuit for generating an output signal corresponding to a potential difference between the second data line and second dummy data line, a first MOS transistor connected between the first and second data lines, a first load circuit for charging the second data line, a second MOS transistor connected between the first and second dummy data lines, and a second load circuit for charging the second dummy data lines.
    Type: Grant
    Filed: December 26, 1990
    Date of Patent: August 11, 1992
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuichi Tatsumi, Hidenobu Minagawa, Hiroshi Iwahashi, Masamichi Asano, Mizuho Imai
  • Patent number: 5010520
    Abstract: In a nonvolatile semiconductor memory device, a wiring layer is connected between a power source and a memory cell. Resistance of the wiring layer is larger than the on-resistance of a load transistor, so that the load transistor substantially determines the load characteristic. Therefore, the load characteristic curve is more gentle in inclination and more rectilinear in shape. This makes the data writing operation stable against a variance in the channel lengths of manufactured transistors forming the memory cells.
    Type: Grant
    Filed: July 27, 1988
    Date of Patent: April 23, 1991
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hidenobu Minagawa, Yuuichi Tatsumi, Hiroshi Iwahashi, Masamichi Asano, Hiroto Nakai, Mizuho Imai
  • Patent number: 4967394
    Abstract: A semiconductor memory device in which data can be read out in response to an address signal comprises power source lines, a plurality of row and column conductive lines, a memory cell array including nonvolatile memory cells arranged in a matrix form of rows and columns and respectively connected to the plurality of row and column lines and the power source lines, a first selector circuit for generating a signal for selecting the row conductive lines in response to an address signal, a dummy row line, and a dummy memory cells each having a source, a drain and a control gate connected to the dummy row line.
    Type: Grant
    Filed: September 8, 1988
    Date of Patent: October 30, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hidenobu Minagawa, Yuuichi Tatsumi, Hiroshi Iwahashi, Masamichi Asano, Mizuho Imai
  • Patent number: 4916334
    Abstract: A semiconductor integrated circuit includes a CMOS circuit operated on a voltage of a first voltage level to set an output node thereof to a voltage of the first voltage level or a reference voltage; an output circuit for controlling supply of a voltage of a second voltage level which is higher than the first voltage level to a signal output node; and an isolation MOS transistor having a current path connected between the output node of the CMOS circuit and the signal output node and a gate connected to receive a control signal. The output node of the CMOS circuit is set to the reference voltage with the conduction resistance of the isolation MOS transistor kept high after the lapse of period in which the voltage of the second voltage level is kept supplied to the signal output node. After this, the conduction resistance of the isolation MOS transistor is reduced in response to the control signal.
    Type: Grant
    Filed: July 29, 1988
    Date of Patent: April 10, 1990
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hidenobu Minagawa, Yuuichi Tatsumi, Hiroshi Iwahashi, Masamichi Asano, Mizuho Imai
  • Patent number: 4882507
    Abstract: A semiconductor integrated circuit includes an output circuit and a control circuit for controlling the output circuit. The control circuit controls the output circuit so as to charge or discharge a preset node in the output circuit at a rate different from an ordinary charging or discharging rate for a preset period of time after a control signal has been changed in level.
    Type: Grant
    Filed: July 29, 1988
    Date of Patent: November 21, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuichi Tatsumi, Hidenobu Minagawa, Hiroshi Iwahashi, Masamichi Asano, Mizuho Imai
  • Patent number: 4858192
    Abstract: A semiconductor memory device has a redundancy circuit for compensating a defective bit when it occurs in the main memory cells. The redundancy circuit includes spare memory cells, a spare row decoder for selecting the spare memory cells, a first circuit section for inhibiting the use of the main row decoder when the spare row decoder is used, and a second circuit section for selecting the spare row decoder when an address specifying the main row line connected to the defective memory cell is denoted.
    Type: Grant
    Filed: July 28, 1988
    Date of Patent: August 15, 1989
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yuuichi Tatsumi, Hidenobu Minagawa, Hiroshi Iwahashi, Masamichi Asano, Mizuho Imai
  • Patent number: 4697101
    Abstract: A semiconductor integrated circuit which has a CMOS inverter formed of p- and n-channel MOSFETs, and a D-type n-channel MOSFET coupled at the gate to the output terminal of the CMOS inverter, having one end coupled to a high voltage terminal and the other end coupled to the drain of the p-channel MOSFET.
    Type: Grant
    Filed: August 29, 1984
    Date of Patent: September 29, 1987
    Assignees: Kabushiki Kaisha Toshiba, Toshiba Micro-Computer Engineering Corp., Tosbac Computer System Co., Ltd.
    Inventors: Hiroshi Iwahashi, Masamichi Asano, Masaki Momodomi, Hidenobu Minagawa, Kazuto Suzuki, Akira Narita
  • Patent number: 4611301
    Abstract: Data is read out from memory cells in which "0" level and "1" level binary data have been stored, and a signal potential responsive to the readout data is compared with a comparison potential by a sense amplifier, thereby sensing the data. In a comparison potential generator, the above comparison potential is set to have the intermediate potential between a potential obtained by a dummy cell in which the "1" level data has been stored, and a potential obtained by a dummy cell in which the "0" level data has been stored.
    Type: Grant
    Filed: April 6, 1984
    Date of Patent: September 9, 1986
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Hiroshi Iwahashi, Masamichi Asano, Hidenobu Minagawa