Patents by Inventor Manabu Sakaniwa

Manabu Sakaniwa 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: 11881267
    Abstract: A semiconductor memory device includes a substrate, gate electrodes, a semiconductor layer opposed to gate electrodes, an electric charge accumulating layer disposed between gate electrodes and the semiconductor layer, a conductive layer connected to one end portion of the semiconductor layer, and a control circuit electrically connected to gate electrodes and the conductive layer. Gate electrodes include first gate electrodes, second gate electrodes, and third gate electrode. The control circuit is configured to perform an erase operation. The erase operation includes: at least one-time first operation that applies a first voltage to the conductive layer; a second operation performed after the first operation, the second operation applying a second voltage to the third gate electrode; and at least one-time third operation performed after the second operation, the third operation applying a third voltage same as or larger than the first voltage to the conductive layer.
    Type: Grant
    Filed: March 9, 2022
    Date of Patent: January 23, 2024
    Assignee: KIOXIA CORPORATION
    Inventors: Manabu Sakaniwa, Yasuhiro Shiino, Kota Nishikawa, Yu Ishiyama, Shinji Suzuki
  • Publication number: 20230056364
    Abstract: A semiconductor memory device includes a substrate, gate electrodes, a semiconductor layer opposed to gate electrodes, an electric charge accumulating layer disposed between gate electrodes and the semiconductor layer, a conductive layer connected to one end portion of the semiconductor layer, and a control circuit electrically connected to gate electrodes and the conductive layer. Gate electrodes include first gate electrodes, second gate electrodes, and third gate electrode. The control circuit is configured to perform an erase operation. The erase operation includes: at least one-time first operation that applies a first voltage to the conductive layer; a second operation performed after the first operation, the second operation applying a second voltage to the third gate electrode; and at least one-time third operation performed after the second operation, the third operation applying a third voltage same as or larger than the first voltage to the conductive layer.
    Type: Application
    Filed: March 9, 2022
    Publication date: February 23, 2023
    Applicant: KIOXIA CORPORATION
    Inventors: Manabu SAKANIWA, Yasuhiro SHIINO, Kota NISHIKAWA, Yu ISHIYAMA, Shinji SUZUKI
  • Patent number: 8767477
    Abstract: A non-volatile semiconductor memory device according to one embodiment of the present invention includes a memory cell array and a control unit. The control unit is configured to control a repeat of an erase operation, an erase verify operation, and a step-up operation. The control unit is configured to perform a soft-programming operation of setting the memory cells from an over-erased state to a first threshold voltage distribution state when, in a series of erase operations, the number of erase voltage applications is more than a first number and less than a second number (the first number<the second number). The control unit is configured not to perform the soft-programming operation when the number of erase voltage applications is equal to or less than the first number or equal to or more than the second number.
    Type: Grant
    Filed: April 17, 2013
    Date of Patent: July 1, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koki Ueno, Eietsu Takahashi, Shigefumi Irieda, Yasuhiro Shiino, Manabu Sakaniwa
  • Publication number: 20130229873
    Abstract: A non-volatile semiconductor memory device according to one embodiment of the present invention includes a memory cell array and a control unit. The control unit is configured to control a repeat of an erase operation, an erase verify operation, and a step-up operation. The control unit is configured to perform a soft-programming operation of setting the memory cells from an over-erased state to a first threshold voltage distribution state when, in a series of erase operations, the number of erase voltage applications is more than a first number and less than a second number (the first number<the second number). The control unit is configured not to perform the soft-programming operation when the number of erase voltage applications is equal to or less than the first number or equal to or more than the second number.
    Type: Application
    Filed: April 17, 2013
    Publication date: September 5, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Koki UENO, Eietsu Takahashi, Shigefumi Irieda, Yasuhiro Shiino, Manabu Sakaniwa
  • Patent number: 8446777
    Abstract: A non-volatile semiconductor memory device according to one embodiment of the present invention includes a memory cell array and a control unit. The control unit is configured to control a repeat of an erase operation, an erase verify operation, and a step-up operation. The control unit is configured to perform a soft-programming operation of setting the memory cells from an over-erased state to a first threshold voltage distribution state when, in a series of erase operations, the number of erase voltage applications is more than a first number and less than a second number (the first number<the second number). The control unit is configured not to perform the soft-programming operation when the number of erase voltage applications is equal to or less than the first number or equal to or more than the second number.
    Type: Grant
    Filed: October 25, 2011
    Date of Patent: May 21, 2013
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koki Ueno, Eietsu Takahashi, Shigefumi Irieda, Yasuhiro Shiino, Manabu Sakaniwa
  • Publication number: 20130044544
    Abstract: According to one embodiment, a nonvolatile memory device includes a circuit and a memory cell. The circuit outputs a program voltage. The memory cell is programmed data by being applied the program voltage. The circuit outputs the program voltage so as to satisfy the following formulae, in the case of repeating an output of the program voltage n times (n is an integer not less than 3), when the program voltage in the k-th output (k is an integer not less than 2 and not greater than n) is set to Vpgm(k), a constant voltage is set as ?v1, a time in which the k-th output is continued is set to Tpgm(k), and a constant time is set as ?t1.
    Type: Application
    Filed: March 6, 2012
    Publication date: February 21, 2013
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro SHIINO, Manabu SAKANIWA, Shigefumi IRIEDA, Koki UENO
  • Publication number: 20120281477
    Abstract: According to one embodiment, a semiconductor memory device includes a memory cell array includes a plurality of cell units each composed of a plurality of memory cells which are arranged at intersections of a plurality of bit lines and a plurality of word lines and whose current paths are connected in series and select transistors each connected to either end of the series connection, a voltage generator circuit which generates a voltage applied to the memory cell array, and a control circuit which controls the memory cell array and the voltage generator circuit.
    Type: Application
    Filed: December 1, 2011
    Publication date: November 8, 2012
    Inventors: Manabu Sakaniwa, Koki Ueno, Shigefumi Irieda, Eietsu Takahashi, Yasuhiro Shiino, Daisuke Kouno
  • Publication number: 20120281487
    Abstract: According to one embodiment, a semiconductor memory device includes a memory cell array includes a plurality of memory cell units which are arranged at intersections of a plurality of bit lines and a plurality of word lines and whose current paths are connected in series, a voltage generator circuit which generates a voltage to be applied to the memory cell array, and a control circuit which controls the memory cell array and the voltage generator circuit. The control circuit, when writing data into the memory cell array, performs control so as to apply a first write pass voltage to unselected word lines in the memory cell units and, after a selected word line has reached a write voltage, further apply a voltage to the unselected word lines until a second write pass voltage higher than the first write pass voltage has been reached.
    Type: Application
    Filed: November 3, 2011
    Publication date: November 8, 2012
    Inventors: Manabu SAKANIWA, Koki Ueno, Shigefumi Irieda, Eietsu Takahashi, Yasuhiro Shiino
  • Publication number: 20120269001
    Abstract: A non-volatile semiconductor memory device according to one embodiment of the present invention includes a memory cell array and a control unit. The control unit is configured to control a repeat of an erase operation, an erase verify operation, and a step-up operation. The control unit is configured to perform a soft-programming operation of setting the memory cells from an over-erased state to a first threshold voltage distribution state when, in a series of erase operations, the number of erase voltage applications is more than a first number and less than a second number (the first number<the second number). The control unit is configured not to perform the soft-programming operation when the number of erase voltage applications is equal to or less than the first number or equal to or more than the second number.
    Type: Application
    Filed: October 25, 2011
    Publication date: October 25, 2012
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Koki UENO, Eietsu Takahashi, Shigefumi Irieda, Yasuhiro Shiino, Manabu Sakaniwa