Patents by Inventor Yoshiaki Tabuchi

Yoshiaki Tabuchi 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: 8645795
    Abstract: The present invention provides a nonvolatile semiconductor memory device that can optimize a timing of performing an error detection and correction process to shorten a processing time. Upon receiving a write request to a memory cell array including a variable resistive element where information is stored based on a resistance state of a variable resistor, an input/output buffer outputs write data to a write control unit and an ECC control unit. The write control unit performs a data write process of writing divided data, obtained by dividing the write data into a predetermined number of data, to the databanks. The ECC control unit generates a first error correction code by performing an error correction code generation process to the write data or the divided data, in parallel with the data write process. The write control unit performs a code write process of writing first test data into an ECC bank.
    Type: Grant
    Filed: May 3, 2012
    Date of Patent: February 4, 2014
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Kazuya Ishihara, Yoshiaki Tabuchi
  • Patent number: 8450713
    Abstract: A three-dimensional memory cell array of memory cells with two terminals having a variable resistive element is formed such that: one ends of memory cells adjacent in Z direction are connected to one of middle selection lines extending in Z direction aligned in X and Y directions; the other ends of the memory cells located at the same point in Z direction are connected to one of third selection lines aligned in Z direction; a two-dimensional array where selection transistors are aligned in X and Y directions is adjacent to the memory cell array in Z direction; gates of selection transistors adjacent in X direction, drains of selection transistors adjacent in Y direction and sources of selection transistors are connected to same first selection line, second selection line, and different middle selection lines, respectively; and first, second and third selection lines are connected to X, Y and Z decoders, respectively.
    Type: Grant
    Filed: February 26, 2010
    Date of Patent: May 28, 2013
    Assignee: Sharp Kabushiki Kaisha
    Inventors: Nobuyoshi Awaya, Yoshiji Ohta, Yoshiaki Tabuchi
  • Publication number: 20120319071
    Abstract: The present invention provides a variable resistive element that can perform a stable switching operation at low voltage and low current, and also provides a low-power consumption large-capacity non-volatile semiconductor memory device including the variable resistive element. The non-volatile semiconductor memory device is a device using a variable resistive element, which includes a variable resistor between a first electrode and a second electrode, for storing information, wherein an oxygen concentration of a hafnium oxide (HfOx) film or a zirconium oxide (ZrOx) film constituting the variable resistor is optimized such that a stoichiometric composition ratio x of oxygen to Hf or Zr falls within a range of 1.7?x?1.97.
    Type: Application
    Filed: June 13, 2012
    Publication date: December 20, 2012
    Inventors: Nobuyoshi AWAYA, Takahiro SHIBUYA, Takashi NAKANO, Yoshiaki TABUCHI, Yushi INOUE, Yukio TAMAI
  • Publication number: 20120297268
    Abstract: The present invention provides a nonvolatile semiconductor memory device that can optimize a timing of performing an error detection and correction process to shorten a processing time. Upon receiving a write request to a memory cell array including a variable resistive element where information is stored based on a resistance state of a variable resistor, an input/output buffer outputs write data to a write control unit and an ECC control unit. The write control unit performs a data write process of writing divided data, obtained by dividing the write data into a predetermined number of data, to the databanks. The ECC control unit generates a first error correction code by performing an error correction code generation process to the write data or the divided data, in parallel with the data write process. The write control unit performs a code write process of writing first test data into an ECC bank.
    Type: Application
    Filed: May 3, 2012
    Publication date: November 22, 2012
    Inventors: Kazuya ISHIHARA, Yoshiaki Tabuchi
  • Publication number: 20100219392
    Abstract: A three-dimensional memory cell array of memory cells with two terminals having a variable resistive element is formed such that: one ends of memory cells adjacent in Z direction are connected to one of middle selection lines extending in Z direction aligned in X and Y directions; the other ends of the memory cells located at the same point in Z direction are connected to one of third selection lines aligned in Z direction; a two-dimensional array where selection transistors are aligned in X and Y directions is adjacent to the memory cell array in Z direction; gates of selection transistors adjacent in X direction, drains of selection transistors adjacent in Y direction and sources of selection transistors are connected to same first selection line, second selection line, and different middle selection lines, respectively; and first, second and third selection lines are connected to X, Y and Z decoders, respectively.
    Type: Application
    Filed: February 26, 2010
    Publication date: September 2, 2010
    Inventors: Nobuyoshi Awaya, Yoshiji Ohta, Yoshiaki Tabuchi
  • Patent number: 7465980
    Abstract: A ferroelectric memory device includes a gate electrode formed on a semiconductor body via a ferroelectric film, first and second diffusion regions being formed in the semiconductor body at respective sides of a channel region, wherein the ferroelectric film comprises a first region located in the vicinity of the first diffusion region, a second region located in the vicinity of the second diffusion region, and a third region located between the first and second regions, wherein the first, second and third regions carry respective, mutually independent polarizations.
    Type: Grant
    Filed: September 8, 2005
    Date of Patent: December 16, 2008
    Assignees: Fujitsu Limited, Tokyo Institute of Technology
    Inventors: Yoshihiro Arimoto, Hiroshi Ishihara, Tetsuro Tamura, Hiromasa Hoko, Koji Aizawa, Yoshiaki Tabuchi, Masaomi Yamaguchi, Yasuo Nara, Kazuhiro Takahashi, Satoshi Hasegawa
  • Publication number: 20060081901
    Abstract: A ferroelectric memory device includes a gate electrode formed on a semiconductor body via a ferroelectric film, first and second diffusion regions being formed in the semiconductor body at respective sides of a channel region, wherein the ferroelectric film comprises a first region located in the vicinity of the first diffusion region, a second region located in the vicinity of the second diffusion region, and a third region located between the first and second regions, wherein the first, second and third regions carry respective, mutually independent polarizations.
    Type: Application
    Filed: September 8, 2005
    Publication date: April 20, 2006
    Applicants: FUJITSU LIMTED, TOKYO INSTITUTE OF TECHNOLOGY
    Inventors: Yoshihiro Arimoto, Hiroshi Ishihara, Tetsuro Tamura, Hiromasa Hoko, Koji Aizawa, Yoshiaki Tabuchi, Masaomi Yamaguchi, Yasuo Nara, Kazuhiro Takahashi, Satoshi Hasegawa