Patents by Inventor Takahiko Sasaki

Takahiko Sasaki 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: 20110199838
    Abstract: According to one embodiment, a semiconductor storage device includes a three-dimensional memory cell array, write drivers, and a program voltage control circuit. In the three-dimensional memory cell array, memory cells are three-dimensionally arranged. The write drivers are arranged to be distributed under the three-dimensional memory cell array and apply a program voltage to the memory cells during writing in the memory cells. The program voltage control circuit is arranged around the three-dimensional memory cell array and performs control for making the write drivers to generate the program voltage.
    Type: Application
    Filed: February 4, 2011
    Publication date: August 18, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yuri TERADA, Takahiko Sasaki
  • Publication number: 20110157958
    Abstract: According to one embodiment, a semiconductor memory device comprises a memory cell array and a control circuit. The control circuit applies a certain potential difference to a selected one of the memory cells. The control circuit comprises a current mirror circuit, a reference current generating circuit, and a detecting circuit. The current mirror circuit produces a mirror current having a current value identical to that of a cell current flowing in the selected one of the memory cells. The reference current generating circuit produces a reference current, the reference current having a current value that differs from the current value of the mirror current by a certain current value. The detecting circuit detects transition of a resistance state of the selected one of the memory cells based on a magnitude relation of the mirror current and the reference current.
    Type: Application
    Filed: September 20, 2010
    Publication date: June 30, 2011
    Applicant: Kabushiki Kaisha Toshiba
    Inventor: Takahiko SASAKI
  • Publication number: 20110158029
    Abstract: According to one embodiment, a word line driving circuit includes a driver and a booster circuit. The driver drives a word line based on an output of an inverter. The booster circuit connects a boosting capacitor to a source side of a P-channel field effect transistor of the inverter to boost the potential of the word line.
    Type: Application
    Filed: September 17, 2010
    Publication date: June 30, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventor: Takahiko SASAKI
  • Publication number: 20110141794
    Abstract: According to one embodiment, a semiconductor memory device includes a memory cell array includes memory cells, lines provided to correspond to the memory cells, a first decoder configured to select a first line as an inspection target from the lines, a second decoder configured to select a second line for generating a reference voltage from the lines, a driver configured to charge the first and second lines, a discharging circuit configured to simultaneously discharge the first and second lines, and a sense amplifier configured to compare a voltage of the first line with a voltage of the second line to detect a defect of the first line while the first line is discharged.
    Type: Application
    Filed: September 17, 2010
    Publication date: June 16, 2011
    Inventors: Tomonori Kurosawa, Takahiko Sasaki, Kazushige Kanda
  • Publication number: 20110066878
    Abstract: A semiconductor storage device includes a memory cell array including memory cells arranged at respective intersections between first wirings and second wirings. Each of the memory cells includes a rectifier element and a variable resistance element connected in series. A control circuit is configured to apply a first voltage to a selected first wiring and a second voltage lower than the first voltage to a selected second wiring so that a certain potential difference is applied to a selected memory cell positioned at an intersection between the selected first wiring and the selected second wiring. The control circuit performs a concurrent read operation to perform a read operation from plural memory cells concurrently by applying the first voltage to a plurality of the first wirings concurrently. It is possible to switch the number of the first wirings to be applied with the first voltage concurrently in the concurrent read operation.
    Type: Application
    Filed: September 17, 2010
    Publication date: March 17, 2011
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koji Hosono, Yuri Terada, Takahiko Sasaki
  • Publication number: 20100302831
    Abstract: A memory cell of a static random access memory (SRAM) includes a pair of drive transistors, a pair of load transistors, a pair of write-only transfer transistors, a pair of read-only transfer transistors, a pair of read-only drive transistors, and a pair of column selection transistors. The memory cell also includes a word line, a pair of write bit lines, a pair of read bit lines, and a column selection line.
    Type: Application
    Filed: May 28, 2010
    Publication date: December 2, 2010
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yasuhisa Takeyama, Osamu Hirabayashi, Takahiko Sasaki, Yuki Fujimura
  • Patent number: 7746685
    Abstract: SRAM cells are arranged in matrix along a first and a second bit line and a word line for single-ended reading of data from the second bit line. A first NMOS transistor and a first transfer transistor contained in the SRAM cell are formed in a first well with respective identical gate lengths and gate widths. A second NMOS transistor and a second transfer transistor contained in the SRAM cell are formed in a second well with respective identical gate lengths and gate widths. These gate widths are made wider than the gate widths of the first NMOS transistor and the first transfer transistor.
    Type: Grant
    Filed: September 10, 2008
    Date of Patent: June 29, 2010
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Atsushi Kawasumi, Takahiko Sasaki
  • Publication number: 20090147561
    Abstract: A semiconductor storage device includes a memory cell array having a plurality of SRAM cells arranged along a pair of bit lines that extend along a first direction. A read circuit is arranged for each column at one side of the memory cell array and detects a potential of any one of the pair of bit lines. A write circuit is arranged, separately from the read circuit, at the other side of the memory cell array. The write circuit provides written data to the pair of bit lines to write data to the SRAM cells.
    Type: Application
    Filed: December 4, 2008
    Publication date: June 11, 2009
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Takahiko Sasaki, Atsushi Kawasumi
  • Publication number: 20090067222
    Abstract: SRAM cells are arranged in matrix along a first and a second bit line and a word line for single-ended reading of data from the second bit line. A first NMOS transistor and a first transfer transistor contained in the SRAM cell are formed in a first well with respective identical gate lengths and gate widths. A second NMOS transistor and a second transfer transistor contained in the SRAM cell are formed in a second well with respective identical gate lengths and gate widths. These gate widths are made wider than the gate widths of the first NMOS transistor and the first transfer transistor.
    Type: Application
    Filed: September 10, 2008
    Publication date: March 12, 2009
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Atsushi KAWASUMI, Takahiko Sasaki
  • Publication number: 20080258256
    Abstract: A fuse link is formed between first and second terminals. The first and second terminals and fuse link have a polysilicon layer and a layer formed on the polysilicon layer and containing a metal element. At least a portion of the fuse link is an amorphous silicon layer.
    Type: Application
    Filed: April 8, 2008
    Publication date: October 23, 2008
    Inventors: Nobuaki Otsuka, Takahiko Sasaki, Shuso Fujii
  • Patent number: 7368801
    Abstract: A fuse link is formed between first and second terminals. The first and second terminals and fuse link have a polysilicon layer and a layer formed on the polysilicon layer and containing a metal element. At least a portion of the fuse link is an amorphous silicon layer.
    Type: Grant
    Filed: May 24, 2004
    Date of Patent: May 6, 2008
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Nobuaki Otsuka, Takahiko Sasaki, Shuso Fujii
  • Publication number: 20080049484
    Abstract: A data write transfer gate and a write driver transistor are connected to a data latch circuit for storing data, thereby producing a write data path. The data path is controlled by a word line and a data write bit line. In addition, a read drive transistor and a read transfer gate are connected to the latch circuit, thereby producing a read data path. The data path is controlled by a word line, a read bit line, and the data in the data latch circuit.
    Type: Application
    Filed: July 26, 2007
    Publication date: February 28, 2008
    Inventor: Takahiko SASAKI
  • Publication number: 20050189613
    Abstract: A fuse link is formed between first and second terminals. The first and second terminals and fuse link have a polysilicon layer and a layer formed on the polysilicon layer and containing a metal element. At least a portion of the fuse link is an amorphous silicon layer.
    Type: Application
    Filed: May 24, 2004
    Publication date: September 1, 2005
    Inventors: Nobuaki Otsuka, Takahiko Sasaki, Shuso Fujii