Patents by Inventor Yoshikazu Harada

Yoshikazu Harada 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: 11961583
    Abstract: In one embodiment, a semiconductor storage device includes a plurality of memory chips, at least one of the memory chips including a first controller configured to be shifted to a wait state of generating a peak current, before generating the peak current in accordance with a command. The device further includes a control chip including a second controller configured to search a state of the first controller and control, based on a result of searching the state of the first controller, whether or not to issue a cancel instruction for the wait state to the first controller that has been shifted to the wait state.
    Type: Grant
    Filed: May 12, 2023
    Date of Patent: April 16, 2024
    Assignee: KIOXIA CORPORATION
    Inventors: Akio Sugahara, Yoshikazu Harada, Shoichiro Hashimoto
  • Publication number: 20230290390
    Abstract: In one embodiment, a semiconductor storage device includes a plurality of memory chips, at least one of the memory chips including a first controller configured to be shifted to a wait state of generating a peak current, before generating the peak current in accordance with a command. The device further includes a control chip including a second controller configured to search a state of the first controller and control, based on a result of searching the state of the first controller, whether or not to issue a cancel instruction for the wait state to the first controller that has been shifted to the wait state.
    Type: Application
    Filed: May 12, 2023
    Publication date: September 14, 2023
    Applicant: KIOXIA CORPORATION
    Inventors: Akio SUGAHARA, Yoshikazu HARADA, Shoichiro HASHIMOTO
  • Patent number: 11715535
    Abstract: A semiconductor storage device includes a memory cell connected to a word line, and a control circuit configured to execute a write operation that repeats a program loop including a program operation of applying a program voltage to the word line and a verification operation to be executed after the program operation. The control circuit, during the write operation, increases the program voltage by a first amount each time the program loop is repeated, and after the write operation is interrupted and resumed, changes the increase in the program voltage from the first amount to a second amount, which is a positive number smaller than the first amount.
    Type: Grant
    Filed: February 22, 2021
    Date of Patent: August 1, 2023
    Assignee: Kioxia Corporation
    Inventors: Yoshikazu Harada, Yuji Nagai, Kenro Kikuchi
  • Patent number: 11694731
    Abstract: In one embodiment, a semiconductor storage device includes a plurality of memory chips, at least one of the memory chips including a first controller configured to be shifted to a wait state of generating a peak current, before generating the peak current in accordance with a command. The device further includes a control chip including a second controller configured to search a state of the first controller and control, based on a result of searching the state of the first controller, whether or not to issue a cancel instruction for the wait state to the first controller that has been shifted to the wait state.
    Type: Grant
    Filed: July 14, 2022
    Date of Patent: July 4, 2023
    Assignee: KIOXIA CORPORATION
    Inventors: Akio Sugahara, Yoshikazu Harada, Shoichiro Hashimoto
  • Publication number: 20230092551
    Abstract: A semiconductor storage device of an embodiment includes: a plurality of memory strings each including a plurality of memory cell transistors, the plurality of memory strings being connected in parallel to one another; and a control circuit configured to control a write operation on at least part of the plurality of memory cell transistors. The write operation is executed in response to reception of the write command and the address. The control circuit determines, based on the address, whether to perform a first voltage application operation before the write operation ends. The first voltage application operation applies a predetermined voltage to the plurality of word lines.
    Type: Application
    Filed: June 13, 2022
    Publication date: March 23, 2023
    Applicant: Kioxia Corporation
    Inventors: Manabu SATO, Yoshikazu HARADA, Naoya SHIMMYO
  • Publication number: 20230019345
    Abstract: A semiconductor memory device includes a memory cell array and a control circuit configured to receive a first command set, reject a second command set related to a write operation or an erase operation, in a first time period of executing a first operation on the memory cell array in response to the first command set, receive a third command set related to a read operation in the first time period, and execute the read operation on the memory cell array in response to the third command set.
    Type: Application
    Filed: September 26, 2022
    Publication date: January 19, 2023
    Applicant: Kioxia Corporation
    Inventor: Yoshikazu HARADA
  • Publication number: 20230021244
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of memory cell transistors, a word line connected to a gate of each of the memory cell transistors, a sequencer configured to control an operation of the memory cell array, and an input/output circuit. When the input/output circuit receives a command instructing an operation of continuously reading data of a plurality of pages from the memory cell transistors, the sequencer determines the data of the plurality of pages by continuously applying read voltages corresponding to the plurality of pages to be read, to the word line. In each continuous time period during which the control circuit applies read voltages for determining the data of one of the pages to the word line, the control circuit does not apply any read voltage for determining the data of another one of the pages to the word line.
    Type: Application
    Filed: February 25, 2022
    Publication date: January 19, 2023
    Inventor: Yoshikazu HARADA
  • Publication number: 20220351760
    Abstract: In one embodiment, a semiconductor storage device includes a plurality of memory chips, at least one of the memory chips including a first controller configured to be shifted to a wait state of generating a peak current, before generating the peak current in accordance with a command. The device further includes a control chip including a second controller configured to search a state of the first controller and control, based on a result of searching the state of the first controller, whether or not to issue a cancel instruction for the wait state to the first controller that has been shifted to the wait state.
    Type: Application
    Filed: July 14, 2022
    Publication date: November 3, 2022
    Applicant: KIOXIA CORPORATION
    Inventors: Akio SUGAHARA, Yoshikazu HARADA, Shoichiro HASHIMOTO
  • Patent number: 11487476
    Abstract: According to an embodiment, a semiconductor memory device includes a memory cell array and a control circuit. The control circuit is configured to receive a first command set, receive a second command set related to a read operation while rejecting a command set related to a write operation or erase operation in response to the first command set, and execute the read operation on the memory cell array in response to the second command set.
    Type: Grant
    Filed: February 25, 2021
    Date of Patent: November 1, 2022
    Assignee: KIOXIA CORPORATION
    Inventor: Yoshikazu Harada
  • Patent number: 11423961
    Abstract: In one embodiment, a semiconductor storage device includes a plurality of memory chips, at least one of the memory chips including a first controller configured to be shifted to a wait state of generating a peak current, before generating the peak current in accordance with a command. The device further includes a control chip including a second controller configured to search a state of the first controller and control, based on a result of searching the state of the first controller, whether or not to issue a cancel instruction for the wait state to the first controller that has been shifted to the wait state.
    Type: Grant
    Filed: March 16, 2021
    Date of Patent: August 23, 2022
    Assignee: Kioxia Corporation
    Inventors: Akio Sugahara, Yoshikazu Harada, Shoichiro Hashimoto
  • Patent number: 11398277
    Abstract: A semiconductor storage device of an embodiment includes a control circuit configured to execute a writing sequence in which a loop including a program operation that writes data to memory cells and a program verify operation that verifies the data written in the memory cells is repeated a plurality of times by increasing a program voltage by a predetermined step-up voltage each time, the control circuit being capable of executing reading verify that verifies the data written in the memory cells in the writing sequence, and the control circuit detects characteristic variation of a characteristic that causes disturbance, and determines whether to perform the reading verify based on a result of the detection.
    Type: Grant
    Filed: March 12, 2021
    Date of Patent: July 26, 2022
    Assignee: Kioxia Corporation
    Inventors: Takuya Kusaka, Daisuke Arizono, Yoshikazu Harada
  • Patent number: 11348648
    Abstract: According to an embodiment, a semiconductor memory device includes a memory cell array and a control circuit. The control circuit is configured to suspend a first operation on the memory cell array while the first operation is being performed, to start a first read operation on the memory cell array, and to resume the suspended first operation at least after the first read operation has been started. Upon receipt of a first command, a setting as to whether or not to resume the suspended first operation in response to receipt of a second command is switched. The second command is different from the first command.
    Type: Grant
    Filed: February 28, 2020
    Date of Patent: May 31, 2022
    Assignee: KIOXIA CORPORATION
    Inventor: Yoshikazu Harada
  • Publication number: 20220084595
    Abstract: A semiconductor storage device of an embodiment includes a control circuit configured to execute a writing sequence in which a loop including a program operation that writes data to memory cells and a program verify operation that verifies the data written in the memory cells is repeated a plurality of times by increasing a program voltage by a predetermined step-up voltage each time, the control circuit being capable of executing reading verify that verifies the data written in the memory cells in the writing sequence, and the control circuit detects characteristic variation of a characteristic that causes disturbance, and determines whether to perform the reading verify based on a result of the detection.
    Type: Application
    Filed: March 12, 2021
    Publication date: March 17, 2022
    Applicant: Kioxia Corporation
    Inventors: Takuya KUSAKA, Daisuke ARIZONO, Yoshikazu HARADA
  • Patent number: 11183256
    Abstract: According to a certain embodiment, the semiconductor memory device includes a memory cell array, a control circuit, and a data register storing an erase verify fail flag. An erase target block is divided into word line groups. The control circuit includes: a counter configured to count the number of the erase verify fail flags to be output as a count value for each group; a plurality of counter registers configured to store the count value for each group; an arithmetic circuit configured to take a difference of the plurality of count values respectively stored in the plurality of counter registers and to output a result of the difference as a number of second fail flags; and a comparator configured to compare the number of criteria of the erase verify fail flag and the number of the second fail flags to be output as a memory state detected result.
    Type: Grant
    Filed: June 29, 2020
    Date of Patent: November 23, 2021
    Assignee: Kioxia Corporation
    Inventors: Koichi Shinohara, Katsuki Matsudera, Ian Christopher Gamara, Yoshikazu Harada, Noritaka Kai, Yusuke Tanefusa
  • Patent number: 11170857
    Abstract: A semiconductor memory device includes a memory cell array including a plurality of memory cells, a word line connected in common to gates of the memory cells, and a control circuit configured to execute a read operation on the memory cells by applying a first read voltage to the word line to determine for each of the memory cells whether or not the memory cell has a threshold voltage that is below the first read voltage and a second read voltage to the word line to determine for each of the memory cells whether or not the memory cell has a threshold voltage that is below the second read voltage. The control circuit determines the first read voltage by applying at least first to third voltages to the word line, and determines the second read voltage based on the first read voltage.
    Type: Grant
    Filed: June 25, 2020
    Date of Patent: November 9, 2021
    Assignee: KIOXIA CORPORATION
    Inventor: Yoshikazu Harada
  • Publication number: 20210334044
    Abstract: According to an embodiment, a semiconductor memory device includes a memory cell array and a control circuit. The control circuit is configured to receive a first command set, receive a second command set related to a read operation while rejecting a command set related to a write operation or erase operation in response to the first command set, and execute the read operation on the memory cell array in response to the second command set.
    Type: Application
    Filed: February 25, 2021
    Publication date: October 28, 2021
    Applicant: Kioxia Corporation
    Inventor: Yoshikazu HARADA
  • Publication number: 20210335433
    Abstract: A semiconductor storage device includes a memory cell connected to a word line, and a control circuit configured to execute a write operation that repeats a program loop including a program operation of applying a program voltage to the word line and a verification operation to be executed after the program operation. The control circuit, during the write operation, increases the program voltage by a first amount each time the program loop is repeated, and after the write operation is interrupted and resumed, changes the increase in the program voltage from the first amount to a second amount, which is a positive number smaller than the first amount.
    Type: Application
    Filed: February 22, 2021
    Publication date: October 28, 2021
    Inventors: Yoshikazu HARADA, Yuji NAGAI, Kenro KIKUCHI
  • Patent number: 11101008
    Abstract: A semiconductor memory device includes a memory transistor, a word line, a peripheral circuit, and electrodes connected to the peripheral circuit. In response to a write command via the electrodes, the peripheral circuit can execute a first program operation of applying a first program voltage to the word line one time when the write command is one of an n1-th write command to an n2-th write command corresponding to the memory transistor; and execute a second program operation of applying a second program voltage to the first word line at least one time when the write command is one of an (n2+1)-th write command to an n3-th write command corresponding to the memory transistor. The second program voltage in a k-th second program operation is less than the first program voltage in a k-th first program operation.
    Type: Grant
    Filed: March 2, 2020
    Date of Patent: August 24, 2021
    Assignee: KIOXIA CORPORATION
    Inventors: Masato Endo, Daisuke Arizono, Yoshikazu Harada
  • Publication number: 20210210124
    Abstract: In one embodiment, a semiconductor storage device includes a plurality of memory chips, at least one of the memory chips including a first controller configured to be shifted to a wait state of generating a peak current, before generating the peak current in accordance with a command. The device further includes a control chip including a second controller configured to search a state of the first controller and control, based on a result of searching the state of the first controller, whether or not to issue a cancel instruction for the wait state to the first controller that has been shifted to the wait state.
    Type: Application
    Filed: March 16, 2021
    Publication date: July 8, 2021
    Applicant: TOSHIBA MEMORY CORPORATION
    Inventors: Akio SUGAHARA, Yoshikazu HARADA, Shoichiro HASHIMOTO
  • Patent number: 10991402
    Abstract: In one embodiment, a semiconductor storage device includes a plurality of memory chips, at least one of the memory chips including a first controller configured to be shifted to a wait state of generating a peak current, before generating the peak current in accordance with a command. The device further includes a control chip including a second controller configured to search a state of the first controller and control, based on a result of searching the state of the first controller, whether or not to issue a cancel instruction for the wait state to the first controller that has been shifted to the wait state.
    Type: Grant
    Filed: April 2, 2020
    Date of Patent: April 27, 2021
    Assignee: TOSHIBA MEMORY CORPORATION
    Inventors: Akio Sugahara, Yoshikazu Harada, Shoichiro Hashimoto