Patents by Inventor Naoya Tokiwa

Naoya Tokiwa 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: 11942158
    Abstract: A semiconductor memory device includes memory cells, a first circuit that includes a first latch group including first and second data latch circuits and a second latch group including third and fourth data latch circuits, and a control circuit configured to control a write operation during which first and second data to be written into the memory cells are stored in the first and second data latch circuits, respectively, wherein the first and second data are also stored in the third and fourth data latch circuits, respectively, while the first and second data stored in the first and second data latch circuits, respectively, are being written in the memory cells.
    Type: Grant
    Filed: November 29, 2022
    Date of Patent: March 26, 2024
    Assignee: Kioxia Corporation
    Inventor: Naoya Tokiwa
  • Publication number: 20230377659
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Application
    Filed: July 26, 2023
    Publication date: November 23, 2023
    Inventor: Naoya TOKIWA
  • Patent number: 11756627
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Grant
    Filed: December 29, 2022
    Date of Patent: September 12, 2023
    Assignee: Kioxia Corporation
    Inventor: Naoya Tokiwa
  • Publication number: 20230213993
    Abstract: According to an embodiment, a semiconductor memory device includes a first pin, a first receiving circuit, and a first terminating circuit. The first pin receives a first signal and a second signal having a smaller amplitude than the first signal. The first receiving circuit is connected to the first pin and outputs, based on a comparison between the first signal and a first voltage, a third signal. The first receiving circuit also outputs, based on a comparison between the second signal and a second voltage, a fourth signal having a smaller amplitude than the third signal. The first terminating circuit is connected to the first pin. The first terminating circuit is disabled if the first pin receives the first signal, and enabled if the first pin receives the second signal.
    Type: Application
    Filed: March 9, 2023
    Publication date: July 6, 2023
    Applicant: Kioxia Corporation
    Inventors: Akio SUGAHARA, Yasuhiro HIRASHIMA, Naoya TOKIWA
  • Publication number: 20230134753
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Application
    Filed: December 29, 2022
    Publication date: May 4, 2023
    Inventor: Naoya TOKIWA
  • Publication number: 20230118624
    Abstract: A semiconductor memory device includes memory cells, a first circuit that includes a first latch group including first and second data latch circuits and a second latch group including third and fourth data latch circuits, and a control circuit configured to control a write operation during which first and second data to be written into the memory cells are stored in the first and second data latch circuits, respectively, wherein the first and second data are also stored in the third and fourth data latch circuits, respectively, while the first and second data stored in the first and second data latch circuits, respectively, are being written in the memory cells.
    Type: Application
    Filed: November 29, 2022
    Publication date: April 20, 2023
    Inventor: Naoya TOKIWA
  • Patent number: 11594282
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Grant
    Filed: July 28, 2021
    Date of Patent: February 28, 2023
    Assignee: Kioxia Corporation
    Inventor: Naoya Tokiwa
  • Patent number: 11551760
    Abstract: A semiconductor memory device includes memory cells, a first circuit that includes a first latch group including first and second data latch circuits and a second latch group including third and fourth data latch circuits, and a control circuit configured to control a write operation during which first and second data to be written into the memory cells are stored in the first and second data latch circuits, respectively, wherein the first and second data are also stored in the third and fourth data latch circuits, respectively, while the first and second data stored in the first and second data latch circuits, respectively, are being written in the memory cells.
    Type: Grant
    Filed: February 22, 2021
    Date of Patent: January 10, 2023
    Assignee: KIOXIA CORPORATION
    Inventor: Naoya Tokiwa
  • Publication number: 20210358555
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Application
    Filed: July 28, 2021
    Publication date: November 18, 2021
    Inventor: Naoya TOKIWA
  • Patent number: 11099787
    Abstract: A semiconductor memory includes a first plane that includes a first memory cell array, a second plane that includes a second memory cell array, and a control circuit that includes a first circuit configured to store a first priority for a first operation performed on the first plane and a second circuit configured to store a second priority for a second operation performed on the second plane, and is configured to control the first and second operations based on the first priority and the second priority. When a value of the second priority is higher than a value of the first priority, the control circuit controls the first operation such that a timing of a process executed in the first operation does not overlap with a timing of a process executed in the second operation.
    Type: Grant
    Filed: April 6, 2020
    Date of Patent: August 24, 2021
    Assignee: KIOXIA CORPORATION
    Inventor: Naoya Tokiwa
  • Patent number: 11094380
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Grant
    Filed: October 1, 2020
    Date of Patent: August 17, 2021
    Assignee: KIOXIA CORPORATION
    Inventor: Naoya Tokiwa
  • Publication number: 20210174878
    Abstract: A semiconductor memory device includes memory cells, a first circuit that includes a first latch group including first and second data latch circuits and a second latch group including third and fourth data latch circuits, and a control circuit configured to control a write operation during which first and second data to be written into the memory cells are stored in the first and second data latch circuits, respectively, wherein the first and second data are also stored in the third and fourth data latch circuits, respectively, while the first and second data stored in the first and second data latch circuits, respectively, are being written in the memory cells.
    Type: Application
    Filed: February 22, 2021
    Publication date: June 10, 2021
    Inventor: Naoya TOKIWA
  • Patent number: 10950307
    Abstract: A semiconductor memory device includes memory cells, a first circuit that includes a first latch group including first and second data latch circuits and a second latch group including third and fourth data latch circuits, and a control circuit configured to control a write operation during which first and second data to be written into the memory cells are stored in the first and second data latch circuits, respectively, wherein the first and second data are also stored in the third and fourth data latch circuits, respectively, while the first and second data stored in the first and second data latch circuits, respectively, are being written in the memory cells.
    Type: Grant
    Filed: February 26, 2020
    Date of Patent: March 16, 2021
    Assignee: KIOXIA CORPORATION
    Inventor: Naoya Tokiwa
  • Publication number: 20210020250
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Application
    Filed: October 1, 2020
    Publication date: January 21, 2021
    Inventor: Naoya TOKIWA
  • Publication number: 20200342941
    Abstract: A semiconductor memory device includes memory cells, a first circuit that includes a first latch group including first and second data latch circuits and a second latch group including third and fourth data latch circuits, and a control circuit configured to control a write operation during which first and second data to be written into the memory cells are stored in the first and second data latch circuits, respectively, wherein the first and second data are also stored in the third and fourth data latch circuits, respectively, while the first and second data stored in the first and second data latch circuits, respectively, are being written in the memory cells.
    Type: Application
    Filed: February 26, 2020
    Publication date: October 29, 2020
    Inventor: Naoya TOKIWA
  • Patent number: 10811100
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Grant
    Filed: April 23, 2020
    Date of Patent: October 20, 2020
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventor: Naoya Tokiwa
  • Publication number: 20200251169
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Application
    Filed: April 23, 2020
    Publication date: August 6, 2020
    Inventor: Naoya TOKIWA
  • Publication number: 20200233613
    Abstract: A semiconductor memory includes a first plane that includes a first memory cell array, a second plane that includes a second memory cell array, and a control circuit that includes a first circuit configured to store a first priority for a first operation performed on the first plane and a second circuit configured to store a second priority for a second operation performed on the second plane, and is configured to control the first and second operations based on the first priority and the second priority. When a value of the second priority is higher than a value of the first priority, the control circuit controls the first operation such that a timing of a process executed in the first operation does not overlap with a timing of a process executed in the second operation.
    Type: Application
    Filed: April 6, 2020
    Publication date: July 23, 2020
    Inventor: Naoya TOKIWA
  • Patent number: 10672482
    Abstract: A semiconductor memory device includes a memory block, a plurality of bit lines, a plurality of select gate lines, a plurality of word lines, and a controller. The memory block includes a plurality of memory strings, each memory string including a selection transistor and a plurality of memory cells. The plurality of bit lines are arranged in the first direction and connected to the respective memory strings. The plurality of select gate lines are arranged in the second direction and connected to gates of the respective selection transistors of the memory strings. The plurality of word lines are arranged in the third direction and connected to gates of the respective memory cells of the memory strings. The controller is configured to perform an erase operation in a unit of the memory block, and perform a sequence of erase verify operations.
    Type: Grant
    Filed: December 18, 2019
    Date of Patent: June 2, 2020
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventor: Naoya Tokiwa
  • Patent number: RE49113
    Abstract: A three-dimensionally stacked nonvolatile semiconductor memory of an aspect of the present invention including conductive layers stacked on a semiconductor substrate in such a manner as to be insulated from one another, a bit line which is disposed on the stacked conductive layers, a semiconductor column which extends through the stacked conductive layers, word lines for which the stacked conductive layers except for the uppermost and lowermost conductive layers are used and which have a plate-like planar shape, memory cells provided at intersections of the word lines and the semiconductor column, a register circuit which has information to supply a potential suitable for each of the word lines, and a potential control circuit which reads the information retained in the register circuit in accordance with an input address signal of a word line and which supplies a potential suitable for the word line corresponding to the address signal.
    Type: Grant
    Filed: January 9, 2020
    Date of Patent: June 21, 2022
    Assignee: Kioxia Corporation
    Inventors: Naoya Tokiwa, Hideo Mukai