Patents by Inventor Katsuhiko Hoya

Katsuhiko Hoya 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: 20230420021
    Abstract: According to one embodiment, a memory device includes: a first bank including a first memory cell; a second bank including a second memory cell; and a buffer circuit configured to temporarily stores data, wherein, during a read sequence for the first memory cell, the first bank is configured to: sense a first signal from the first memory cell, set the first memory cell to a reset state after the first signal is sensed, sense a second signal from the first memory cell in the reset state, determine first data stored in the first memory cell, based on the first signal and the second signal, and store the first data in the buffer circuit, and the second bank is configured to: write the first data in the buffer circuit to the second memory.
    Type: Application
    Filed: March 7, 2023
    Publication date: December 28, 2023
    Applicant: Kioxia Corporation
    Inventor: Katsuhiko HOYA
  • Patent number: 11727975
    Abstract: A nonvolatile memory device of an embodiment includes: a first wiring line extending in a first direction; a second wiring line extending in a second direction intersecting the first direction; a memory cell disposed between the first layer and the second layer, and has first and second terminals, the memory cell including a variable resistance element; a first drive circuit capable of supplying a first potential and a second potential lower than the first potential; a second drive circuit supplying a third potential having a different polarity from a polarity of the first potential; a third drive circuit capable of supplying the second potential and a fourth potential higher than the second potential; a fourth drive circuit supplying a fifth potential having a different polarity from a polarity of the first potential; and a control circuit electrically connected to the first to fourth drive circuits.
    Type: Grant
    Filed: September 15, 2021
    Date of Patent: August 15, 2023
    Assignee: Kioxia Corporation
    Inventor: Katsuhiko Hoya
  • Publication number: 20230106886
    Abstract: According to one embodiment, a method for manufacturing a memory system that has memory cells with a variable resistance element and a switching element connected between a first wire and second wire, includes forming the variable resistance elements in the memory system in a low resistance state or a high resistance state, and then bringing each of the variable resistance elements into the low resistance state before performing either of a read operation or a write operation by performing an external initialization process that is different from the read operation and the write operation. In some examples, the variable resistance element can be a magnetoresistance type element and the external initialization process may be exposing the memory cells to an external magnetic field.
    Type: Application
    Filed: February 28, 2022
    Publication date: April 6, 2023
    Inventors: Tadashi Miyakawa, Katsuhiko Hoya
  • Publication number: 20220284939
    Abstract: A nonvolatile memory device of an embodiment includes: a first wiring line extending in a first direction; a second wiring line extending in a second direction intersecting the first direction; a memory cell disposed between the first layer and the second layer, and has first and second terminals, the memory cell including a variable resistance element; a first drive circuit capable of supplying a first potential and a second potential lower than the first potential; a second drive circuit supplying a third potential having a different polarity from a polarity of the first potential; a third drive circuit capable of supplying the second potential and a fourth potential higher than the second potential; a fourth drive circuit supplying a fifth potential having a different polarity from a polarity of the first potential; and a control circuit electrically connected to the first to fourth drive circuits,
    Type: Application
    Filed: September 15, 2021
    Publication date: September 8, 2022
    Applicant: Kioxia Corporation
    Inventor: Katsuhiko HOYA
  • Patent number: 11101319
    Abstract: A semiconductor storage device includes first and second wirings that are in a first layer above the substrate, extend along a first direction, and are adjacent to each other along a second direction, third and fourth wirings that are in a second layer above the first layer, extend along the second direction, and are adjacent to each other along the first direction, first and second memory cells on the first wiring, and a third memory cell on the second wiring. The first to third memory cells each include a variable resistance element and a switching element. The switching element of the first memory cell includes a gate coupled to the third wiring. The switching elements of the second and third memory cells each include a gate coupled to the fourth wiring. The variable resistance elements of the first to third memory cells are formed with equal distances from each other.
    Type: Grant
    Filed: April 2, 2020
    Date of Patent: August 24, 2021
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Tadashi Miyakawa, Katsuhiko Hoya, Hiroyuki Takenaka
  • Publication number: 20200303458
    Abstract: A semiconductor storage device includes first and second wirings that are in a first layer above the substrate, extend along a first direction, and are adjacent to each other along a second direction, third and fourth wirings that are in a second layer above the first layer, extend along the second direction, and are adjacent to each other along the first direction, first and second memory cells on the first wiring, and a third memory cell on the second wiring. The first to third memory cells each include a variable resistance element and a switching element. The switching element of the first memory cell includes a gate coupled to the third wiring. The switching elements of the second and third memory cells each include a gate coupled to the fourth wiring. The variable resistance elements of the first to third memory cells are formed with equal distances from each other.
    Type: Application
    Filed: April 2, 2020
    Publication date: September 24, 2020
    Inventors: Tadashi MIYAKAWA, Katsuhiko HOYA, Hiroyuki TAKENAKA
  • Patent number: 10783946
    Abstract: According to an embodiment, a semiconductor memory device includes: memory cell arrays; word lines respectively connected to rows of each of the memory cell arrays; bit lines respectively connected to columns of each of the memory cell arrays; row selection circuits provided so as to respectively correspond to the memory cell arrays and connected to the word lines; and column selection circuits provided so as to respectively correspond to the memory cell arrays and connected to the bit lines. When an identical row address is received, the row selection circuits perform selection operations of word lines so that word line lengths from selected memory cells to the row selection circuits vary.
    Type: Grant
    Filed: March 13, 2019
    Date of Patent: September 22, 2020
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Tadashi Miyakawa, Katsuhiko Hoya
  • Publication number: 20200168263
    Abstract: According to an embodiment, a semiconductor memory device includes: memory cell arrays; word lines respectively connected to rows of each of the memory cell arrays; bit lines respectively connected to columns of each of the memory cell arrays; row selection circuits provided so as to respectively correspond to the memory cell arrays and connected to the word lines; and column selection circuits provided so as to respectively correspond to the memory cell arrays and connected to the bit lines. When an identical row address is received, the row selection circuits perform selection operations of word lines so that word line lengths from selected memory cells to the row selection circuits vary.
    Type: Application
    Filed: March 13, 2019
    Publication date: May 28, 2020
    Applicant: TOSHIBA MEMORY CORPORATION
    Inventors: Tadashi MIYAKAWA, Katsuhiko HOYA
  • Patent number: 10482990
    Abstract: A memory device of one embodiment includes memory elements which store data and parity; a first decoder which, when scrubbing of the data is performed while no external access is being made to the memory device, uses a syndrome generated from the data and the parity to correct an error of a maximum of N bits in a unit of the data; and a second decoder which, when reading of the data is performed, uses the syndrome to correct an error of a maximum of M bits in a unit of the data. The N bits represent the number of bits smaller than the N bits.
    Type: Grant
    Filed: September 8, 2017
    Date of Patent: November 19, 2019
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventor: Katsuhiko Hoya
  • Patent number: 10338835
    Abstract: According to one embodiment, a memory device includes a memory cell; a first circuit that performs a first read on the memory cell, writes first data in the memory cell on which the first read has been performed, performs a second read on the memory cell in which the first data has been written, determines data from a result of the first read based on a result of the second read, and writes back the determined data into the memory cell; and an error correcting circuit that performs error correction on the determined data.
    Type: Grant
    Filed: March 13, 2017
    Date of Patent: July 2, 2019
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Yoshiaki Osada, Katsuhiko Hoya, Yorinobu Fujino, Kosuke Hatsuda
  • Patent number: 10102062
    Abstract: According to one embodiment, a memory system includes: a first memory cell area where a first memory cell is provided; a second memory cell area where a second memory cell is provided; an ECC circuit which corrects an error of data stored by the first memory cell; and a control circuit which replaces the first memory cell with the second memory cell if the number of times an error is successfully corrected in the first memory cell reaches a first value.
    Type: Grant
    Filed: August 31, 2017
    Date of Patent: October 16, 2018
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Yoshiaki Osada, Katsuhiko Hoya
  • Publication number: 20180277595
    Abstract: A semiconductor storage device includes first and second wirings that are in a first layer above the substrate, extend along a first direction, and are adjacent to each other along a second direction, third and fourth wirings that are in a second layer above the first layer, extend along the second direction, and are adjacent to each other along the first direction, first and second memory cells on the first wiring, and a third memory cell on the second wiring. The first to third memory cells each include a variable resistance element and a switching element. The switching element of the first memory cell includes a gate coupled to the third wiring. The switching elements of the second and third memory cells each include a gate coupled to the fourth wiring. The variable resistance elements of the first to third memory cells are formed with equal distances from each other.
    Type: Application
    Filed: February 28, 2018
    Publication date: September 27, 2018
    Inventors: Tadashi MIYAKAWA, Katsuhiko HOYA, Hiroyuki TAKENAKA
  • Patent number: 10049711
    Abstract: According to one embodiment, a magnetoresistive memory device includes a substrate having a first surface which includes a first direction; and memory elements each having a switchable resistance. A first column of memory elements lined up along the first direction is different from an adjacent second column of memory elements lined up along the first direction at positions of memory elements in the first direction.
    Type: Grant
    Filed: September 6, 2016
    Date of Patent: August 14, 2018
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Keisuke Nakatsuka, Tadashi Miyakawa, Katsuhiko Hoya, Takeshi Hamamoto, Hiroyuki Takenaka
  • Patent number: 9947380
    Abstract: According to one embodiment, a memory includes a magnetoresistive element, a reference cell, a sense amplifier comparing a first current flowing in the magnetoresistive element with a second current flowing in the reference cell, a first transistor having a first control terminal controlling a value of the first current, a second transistor having a second control terminal controlling a value of the second current, and a controller applying a first potential to the first control terminal and a second potential to the second control terminal in a first operation, and applying the first potential to the first control terminal and a third potential larger than the second potential to the second control terminal in a second operation.
    Type: Grant
    Filed: September 15, 2016
    Date of Patent: April 17, 2018
    Assignee: Toshiba Memory Corporation
    Inventors: Masahiko Nakayama, Masashi Kawamura, Katsuhiko Hoya, Mikio Miyata, Minoru Amano
  • Patent number: 9934834
    Abstract: A magnetoresistive memory device includes a variable resistance element and a read circuit. The resistance element has a resistance state, which is one of switchable first and second resistance states. The first and second resistance states exhibit different resistances. Each of the first and second resistance states is reached by a current flowing through the variable resistance element in one of opposing first and second directions. The read circuit passes a read current through the variable resistance element autonomously in the first or second direction in accordance with the resistance state of the variable resistance element.
    Type: Grant
    Filed: August 26, 2016
    Date of Patent: April 3, 2018
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Keisuke Nakatsuka, Katsuhiko Hoya
  • Publication number: 20180074737
    Abstract: According to one embodiment, a memory device includes a memory cell; a first circuit that performs a first read on the memory cell, writes first data in the memory cell on which the first read has been performed, performs a second read on the memory cell in which the first data has been written, determines data from a result of the first read based on a result of the second read, and writes back the determined data into the memory cell; and an error correcting circuit that performs error correction on the determined data.
    Type: Application
    Filed: March 13, 2017
    Publication date: March 15, 2018
    Applicant: TOSHIBA MEMORY CORPORATION
    Inventors: Yoshiaki OSADA, Katsuhiko HOYA, Yorinobu FUJINO, Kosuke HATSUDA
  • Publication number: 20170372798
    Abstract: A memory device of one embodiment includes memory elements which store data and parity; a first decoder which, when scrubbing of the data is performed while no external access is being made to the memory device, uses a syndrome generated from the data and the parity to correct an error of a maximum of N bits in a unit of the data; and a second decoder which, when reading of the data is performed, uses the syndrome to correct an error of a maximum of M bits in a unit of the data. The N bits represent the number of bits smaller than the N bits.
    Type: Application
    Filed: September 8, 2017
    Publication date: December 28, 2017
    Applicant: TOSHIBA MEMORY CORPORATION
    Inventor: Katsuhiko HOYA
  • Publication number: 20170364407
    Abstract: According to one embodiment, a memory system includes: a first memory cell area where a first memory cell is provided; a second memory cell area where a second memory cell is provided; an ECC circuit which corrects an error of data stored by the first memory cell; and a control circuit which replaces the first memory cell with the second memory cell if the number of times an error is successfully corrected in the first memory cell reaches a first value.
    Type: Application
    Filed: August 31, 2017
    Publication date: December 21, 2017
    Applicant: TOSHIBA MEMORY CORPORATION
    Inventors: Yoshiaki OSADA, Katsuhiko HOYA
  • Patent number: RE46702
    Abstract: A memory according to an embodiment includes bit lines, word lines, source lines, magnetic tunnel junction elements and transistors that are serially connected between the bit lines and the source lines, respectively, and a sense amplifier that detects data stored in the magnetic tunnel junction elements. The semiconductor storage device includes multiplexers between the bit lines and the sense amplifier in order to select one of the bit lines to be connected to the sense amplifier, and write amplifiers that are located corresponding to memory cell blocks each of which includes memory cells each including the magnetic tunnel junction element and the transistor and are connected to the bit lines or connected via the multiplexers to the bit lines. To write data, the sense amplifier applies a write voltage to the bit lines and then the write amplifiers hold the write voltage.
    Type: Grant
    Filed: July 8, 2015
    Date of Patent: February 6, 2018
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Katsuhiko Hoya, Kenji Tsuchida
  • Patent number: RE47639
    Abstract: A semiconductor storage device includes plural bit lines and plural word lines. The memory cell array has plural memory cells that are connected with the bit lines and word lines, and can store data. Plural sense amplifiers detect the data stored in the memory cells. Plural write drivers write data in the memory cells. A comparison buffer temporarily stores the write data to be written in the memory cells by the write driver. In a series of write sequences, the comparison buffer stores the read data from the memory cells selected as the write object and the write data to be written in the selected memory cells. After a series of write sequences, when the pre-charge command for resetting the voltage of the bit lines is received, the write execution command is executed so that the comparison buffer executes write in the selected memory cells.
    Type: Grant
    Filed: January 22, 2016
    Date of Patent: October 8, 2019
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventor: Katsuhiko Hoya