Patents by Inventor Ryu Ogiwara

Ryu Ogiwara 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: 20240038279
    Abstract: According to one embodiment, in a semiconductor memory device, multiple first memory cells are connected in parallel between a first local bit line and a local source line. Multiple second memory cells are connected in parallel between a second local bit line and the local source line. Each of the multiple first memory cells includes a first cell transistor and a first resistance change element connected in series. Each of the multiple second memory cells includes a second cell transistor and a second resistance change element connected in series. A first selection gate line extends in a second direction across multiple cell blocks arranged in the second direction. A second selection gate line is placed on the opposite side of the first selection gate line with the local source line interposed therebetween. The second selection gate line extends in the second direction across multiple cell blocks arranged in the second direction.
    Type: Application
    Filed: July 26, 2023
    Publication date: February 1, 2024
    Applicant: Kioxia Corporation
    Inventors: Ryu OGIWARA, Hidehiro SHIGA, Daisaburo TAKASHIMA
  • Publication number: 20230413584
    Abstract: A memory device includes: a first interconnect; a second interconnect; a first string and a second string whose first ends are coupled to the first interconnect; a third string and a fourth string whose second ends are coupled to the second interconnect; a third interconnect; and driver. The third interconnect is coupled to second ends of the first and second strings and to first ends of the third and fourth strings. Each of the first, second, third, and fourth strings includes a first switch element and a memory cell coupled in series. The memory cell includes a second switch element and a resistance change element coupled in parallel. The third interconnect is coupled to the driver via the first interconnect or the second interconnect.
    Type: Application
    Filed: August 8, 2023
    Publication date: December 21, 2023
    Applicant: Kioxia Corporation
    Inventors: Takahiko IIZUKA, Daisaburo TAKASHIMA, Ryu OGIWARA, Rieko FUNATSUKI, Yoshiki KAMATA, Misako MOROTA, Yoshiaki ASAO, Yukihiro NOMURA
  • Patent number: 11765916
    Abstract: A memory device includes: a first interconnect; a second interconnect; a first string and a second string whose first ends are coupled to the first interconnect; a third string and a fourth string whose second ends are coupled to the second interconnect; a third interconnect; and driver. The third interconnect is coupled to second ends of the first and second strings and to first ends of the third and fourth strings. Each of the first, second, third, and fourth strings includes a first switch element and a memory cell coupled in series. The memory cell includes a second switch element and a resistance change element coupled in parallel. The third interconnect is coupled to the driver via the first interconnect or the second interconnect.
    Type: Grant
    Filed: June 16, 2021
    Date of Patent: September 19, 2023
    Assignee: Kioxia Corporation
    Inventors: Takahiko Iizuka, Daisaburo Takashima, Ryu Ogiwara, Rieko Funatsuki, Yoshiki Kamata, Misako Morota, Yoshiaki Asao, Yukihiro Nomura
  • Patent number: 11744088
    Abstract: According to one embodiment, a memory device includes: a first variable resistance layer; first and second semiconductor layers being in contact with the first variable resistance layer; a first word line; a second word line being adjacent to the first word line; and a third word line being adjacent to the first and second word lines with the first semiconductor layer, the first variable resistance layer, and the second semiconductor layer interposed therebetween, and provided between the first word line and the second word line. In the first variable resistance layer, a first region including a shortest path connecting the first word line and the third word line functions as a first memory cell, and a second region including a shortest path connecting the third word line and the second word line functions as a second memory cell.
    Type: Grant
    Filed: October 6, 2021
    Date of Patent: August 29, 2023
    Assignee: Kioxia Corporation
    Inventors: Ryu Ogiwara, Daisaburo Takashima, Takahiko Iizuka
  • Patent number: 11721371
    Abstract: According to one embodiment, a memory device includes: a plurality of memory cells stacked in a first direction orthogonal to a substrate and each including a memory element having at least three resistance states and a selector coupled in parallel to the memory element; a bit line electrically coupled to the memory cells and extending in a second direction intersecting the first direction; and a sense amplifier configured to compare a voltage of the bit line with a plurality of reference voltages and sense data stored in the memory cells.
    Type: Grant
    Filed: October 6, 2021
    Date of Patent: August 8, 2023
    Assignee: Kioxia Corporation
    Inventors: Ryu Ogiwara, Daisaburo Takashima, Takahiko Iizuka
  • Patent number: 11651818
    Abstract: According to one embodiment, a memory device includes: a variable resistance memory region; a semiconductor layer; an insulating layer; first and second word lines; and a first select gate line. When information stored in the first memory cell is read, or when information is written into the first memory cell, after a voltage of the first select gate line is set to a first voltage and voltages of the first and second word lines are set to a second voltage, the voltage of the first select gate line is increased from the first voltage to a third voltage. After the voltage of the first select gate line is increased to at least the second voltage, the voltage of the first word line is decreased from the second voltage to the first voltage, and the voltage of the second word line is increased from the second voltage to a fourth voltage.
    Type: Grant
    Filed: July 27, 2021
    Date of Patent: May 16, 2023
    Assignee: KIOXIA CORPORATION
    Inventors: Ryu Ogiwara, Daisaburo Takashima, Takahiko Iizuka
  • Patent number: 11615840
    Abstract: According to one embodiment, a memory device includes a memory cell including a resistance change memory element in which a plurality of data values according to resistance are allowed to be set, and a selector element connected to the resistance change memory element in series, a word line supplying a select signal for selecting the resistance change memory element by the selector element to the memory cell, a bit line to which a data signal according to a data value set in the resistance change memory element is read, a load circuit connected to the memory cell in series and functioning as a load, and a comparator circuit which compares a voltage obtained by the load circuit with a plurality of reference voltages.
    Type: Grant
    Filed: September 16, 2020
    Date of Patent: March 28, 2023
    Assignee: Kioxia Corporation
    Inventors: Ryu Ogiwara, Daisaburo Takashima, Takahiko Iizuka
  • Publication number: 20220367568
    Abstract: A memory device includes a memory cell and a first select transistor. The memory cell includes a variable resistance memory region, a first semiconductor layer being in contact with the variable resistance memory region, a first insulating layer being in contact with the first semiconductor layer, and a first voltage application electrode being in contact with the first insulating layer. The first select transistor includes a second semiconductor layer, a second insulating layer being in contact with the second semiconductor layer, and a second voltage application electrode extending in the second direction and being in contact with the second insulating layer.
    Type: Application
    Filed: July 29, 2022
    Publication date: November 17, 2022
    Applicant: Kioxia Corporation
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA, Takahiko IIZUKA
  • Publication number: 20220108729
    Abstract: According to one embodiment, a memory device includes: a plurality of memory cells stacked in a first direction orthogonal to a substrate and each including a memory element having at least three resistance states and a selector coupled in parallel to the memory element; a bit line electrically coupled to the memory cells and extending in a second direction intersecting the first direction; and a sense amplifier configured to compare a voltage of the bit line with a plurality of reference voltages and sense data stored in the memory cells.
    Type: Application
    Filed: October 6, 2021
    Publication date: April 7, 2022
    Applicant: Kioxia Corporation
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA, Takahiko IIZUKA
  • Publication number: 20220109024
    Abstract: According to one embodiment, a memory device includes: a first variable resistance layer; first and second semiconductor layers being in contact with the first variable resistance layer; a first word line; a second word line being adjacent to the first word line; and a third word line being adjacent to the first and second word lines with the first semiconductor layer, the first variable resistance layer, and the second semiconductor layer interposed therebetween, and provided between the first word line and the second word line. In the first variable resistance layer, a first region including a shortest path connecting the first word line and the third word line functions as a first memory cell, and a second region including a shortest path connecting the third word line and the second word line functions as a second memory cell.
    Type: Application
    Filed: October 6, 2021
    Publication date: April 7, 2022
    Applicant: Kioxia Corporation
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA, Takahiko IIZUKA
  • Publication number: 20220028452
    Abstract: According to one embodiment, a memory device includes: a variable resistance memory region; a semiconductor layer; an insulating layer; first and second word lines; and a first select gate line. When information stored in the first memory cell is read, or when information is written into the first memory cell, after a voltage of the first select gate line is set to a first voltage and voltages of the first and second word lines are set to a second voltage, the voltage of the first select gate line is increased from the first voltage to a third voltage. After the voltage of the first select gate line is increased to at least the second voltage, the voltage of the first word line is decreased from the second voltage to the first voltage, and the voltage of the second word line is increased from the second voltage to a fourth voltage.
    Type: Application
    Filed: July 27, 2021
    Publication date: January 27, 2022
    Applicant: Kioxia Corporation
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA, Takahiko IIZUKA
  • Publication number: 20210399049
    Abstract: A memory device includes: a first interconnect; a second interconnect; a first string and a second string whose first ends are coupled to the first interconnect; a third string and a fourth string whose second ends are coupled to the second interconnect; a third interconnect; and driver. The third interconnect is coupled to second ends of the first and second strings and to first ends of the third and fourth strings. Each of the first, second, third, and fourth strings includes a first switch element and a memory cell coupled in series. The memory cell includes a second switch element and a resistance change element coupled in parallel. The third interconnect is coupled to the driver via the first interconnect or the second interconnect.
    Type: Application
    Filed: June 16, 2021
    Publication date: December 23, 2021
    Applicant: Kioxia Corporation
    Inventors: Takahiko IIZUKA, Daisaburo TAKASHIMA, Ryu OGIWARA, Rieko FUNATSUKI, Yoshiki KAMATA, Misako MOROTA, Yoshiaki ASAO, Yukihiro NOMURA
  • Publication number: 20210287733
    Abstract: According to one embodiment, a driver that sequentially supplies a first voltage, a second voltage higher than the first voltage, and the first voltage to the bit line, during the writing operation to the first memory cell. The driver supplies a third voltage to the second word line and a fourth voltage to the second selecting gate line while changing the voltage of the bit line from the second voltage to the first voltage if a data is a first data. The driver supplies a fifth voltage to the second word line and a sixth voltage to the second selecting gate line while changing the voltage of the bit line from the second voltage to the first voltage if the data is a second data. At least the sixth voltage is larger than the fourth voltage or the fifth voltage is larger than the third voltage.
    Type: Application
    Filed: September 9, 2020
    Publication date: September 16, 2021
    Applicant: Kioxia Corporation
    Inventors: Takahiko IIZUKA, Daisaburo TAKASHIMA, Ryu OGIWARA
  • Patent number: 11120866
    Abstract: According to one embodiment, a driver that sequentially supplies a first voltage, a second voltage higher than the first voltage, and the first voltage to the bit line, during the writing operation to the first memory cell. The driver supplies a third voltage to the second word line and a fourth voltage to the second selecting gate line while changing the voltage of the bit line from the second voltage to the first voltage if a data is a first data. The driver supplies a fifth voltage to the second word line and a sixth voltage to the second selecting gate line while changing the voltage of the bit line from the second voltage to the first voltage if the data is a second data. At least the sixth voltage is larger than the fourth voltage or the fifth voltage is larger than the third voltage.
    Type: Grant
    Filed: September 9, 2020
    Date of Patent: September 14, 2021
    Assignee: Kioxia Corporation
    Inventors: Takahiko Iizuka, Daisaburo Takashima, Ryu Ogiwara
  • Publication number: 20210090647
    Abstract: According to one embodiment, a memory device includes a memory cell including a resistance change memory element in which a plurality of data values according to resistance are allowed to be set, and a selector element connected to the resistance change memory element in series, a word line supplying a select signal for selecting the resistance change memory element by the selector element to the memory cell, a bit line to which a data signal according to a data value set in the resistance change memory element is read, a load circuit connected to the memory cell in series and functioning as a load, and a comparator circuit which compares a voltage obtained by the load circuit with a plurality of reference voltages.
    Type: Application
    Filed: September 16, 2020
    Publication date: March 25, 2021
    Applicant: Kioxia Corporation
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA, Takahiko IIZUKA
  • Patent number: 10950278
    Abstract: According to one embodiment, a nonvolatile memory device includes first and second word lines, first and second bit lines, memory cells each including a resistance change memory element, a global word line including a first global word line portion including a first end portion, a global bit line including a first global bit line portion including a second end portion. The first and second word lines and the first global bit line portion have a first line width and a first line thickness, the first and second bit lines and the first global word line portion have a second line width and a second line thickness.
    Type: Grant
    Filed: September 13, 2019
    Date of Patent: March 16, 2021
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Takahiko Iizuka, Daisaburo Takashima, Ryu Ogiwara
  • Patent number: 10923189
    Abstract: According to one embodiment, a memory device includes a memory cell including a resistance change memory element and a selector element, a word line, a bit line connected to one end of the memory cell, an operational amplifier including a non-inverting input connected to the bit line, an output circuit including a first terminal connected to an output of the operational amplifier, a second terminal connected to the bit line, and a charge/discharge circuit including a capacitor, a charge circuit and a discharge circuit, each including one end connected to an inverting input of the operational amplifier. At the time of falling of a write voltage for the memory cell, a potential of the other end of the memory cell is set higher than a potential of the other end of the discharge circuit.
    Type: Grant
    Filed: March 14, 2019
    Date of Patent: February 16, 2021
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Ryu Ogiwara, Daisaburo Takashima, Takahiko Iizuka
  • Publication number: 20200403035
    Abstract: According to one embodiment, a memory device includes a memory cell and a first select transistor. The memory cell includes: a variable resistance memory region; a first semiconductor layer being in contact with the variable resistance memory region; a first insulating layer being in contact with the first semiconductor layer; and a first voltage application electrode being in contact with the first insulating layer. The first select transistor includes: a second semiconductor layer; a second insulating layer being in contact with the second semiconductor layer; and a second voltage application electrode extending in the second direction and being in contact with the second insulating layer.
    Type: Application
    Filed: June 23, 2020
    Publication date: December 24, 2020
    Applicant: KIOXIA CORPORATION
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA, Takahiko IIZUKA
  • Patent number: 10803932
    Abstract: According to one embodiment, a storage device includes: a memory cell including a storage component to which a plurality of data values are allowed to set in response to a plurality of resistance values of the storage component and a selector connected in series to the storage component; a word line configured to provide a signal to select the memory cell; a bit line configured to receive a data signal from the memory cell; a first conversion circuit configured to nonlinearly convert a first current, generated in response to the data signal input to the bit line, into a first voltage; and a comparison circuit configured to compare the first voltage, converted by the first conversion circuit, with a plurality of reference voltages.
    Type: Grant
    Filed: September 3, 2019
    Date of Patent: October 13, 2020
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Ryu Ogiwara, Daisaburo Takashima, Takahiko Iizuka
  • Publication number: 20200303001
    Abstract: According to one embodiment, a storage device includes: a memory cell including a storage component to which a plurality of data values are allowed to set in response to a plurality of resistance values of the storage component and a selector connected in series to the storage component; a word line configured to provide a signal to select the memory cell; a bit line configured to receive a data signal from the memory cell; a first conversion circuit configured to nonlinearly convert a first current, generated in response to the data signal input to the bit line, into a first voltage; and a comparison circuit configured to compare the first voltage, converted by the first conversion circuit, with a plurality of reference voltages.
    Type: Application
    Filed: September 3, 2019
    Publication date: September 24, 2020
    Applicant: TOSHIBA MEMORY CORPORATION
    Inventors: Ryu OGIWARA, Daisaburo TAKASHIMA, Takahiko IIZUKA