Patents by Inventor Hidehiro Shiga

Hidehiro Shiga 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: 12277989
    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: Grant
    Filed: July 26, 2023
    Date of Patent: April 15, 2025
    Assignee: Kioxia Corporation
    Inventors: Ryu Ogiwara, Hidehiro Shiga, Daisaburo Takashima
  • Patent number: 12211551
    Abstract: A control circuit of a semiconductor memory device performs a write operation on a memory cell transistor of the semiconductor memory device by performing a first pulse application operation of lowering a threshold voltage of the memory cell transistor, a precharge operation, and then a second pulse application operation. In the precharge operation, in a state in which first and second select transistors connected to the memory cell transistor are turned on, a bit line connected to the memory cell transistor is charged by applying a ground voltage to a word line connected to a gate of the memory cell transistor and applying a voltage higher than the ground voltage to a source line. In the second pulse application operation, in a state in which the first select transistor is turned on and the second select transistor is turned off, a program voltage is applied to the word line.
    Type: Grant
    Filed: March 2, 2023
    Date of Patent: January 28, 2025
    Assignee: Kioxia Corporation
    Inventors: Natsuki Sakaguchi, Takashi Maeda, Rieko Funatsuki, Hidehiro Shiga
  • Patent number: 12207480
    Abstract: A variable resistance non-volatile memory includes a semiconductor substrate, a first electrode line extending in a first direction away from the semiconductor substrate, a second electrode line extending in the first direction parallel to the first electrode line, an insulating film between the first and second electrode lines, a variable resistance film formed on the first electrode line, a low electrical resistance layer formed on the variable resistance film and having a lower electrical resistance than the variable resistance film, a semiconductor film in contact with the low electrical resistance layer and the insulating film, and formed on opposite surfaces of the second electrode line, a gate insulator film extending in the first direction and in contact with the semiconductor film, and a voltage application electrode that extends in a second direction that crosses the first direction, and is in contact with the gate insulator film.
    Type: Grant
    Filed: August 31, 2022
    Date of Patent: January 21, 2025
    Assignee: Kioxia Corporation
    Inventors: Tomoki Chiba, Daisaburo Takashima, Hidehiro Shiga
  • Patent number: 12144189
    Abstract: According to a certain embodiment, the 3D stacked semiconductor memory includes: a first electrode line extending in a first direction orthogonal to the semiconductor substrate; a second electrode line adjacent to the first electrode line in a second direction orthogonal to the first direction, and extending in the first direction; a first variable resistance film extending in the first direction and in contact with the second electrode line; a first semiconductor film in contact with the first variable resistance film and the first electrode line; a first potential applying electrode extending in the second direction and in contact with a first insulator layer; a second semiconductor film in contact with a second variable resistance film and the first electrode line; and a second potential applying electrode extending in the second direction and in contact with a second insulator layer. The first and second potential applying electrodes are electrically different nodes.
    Type: Grant
    Filed: September 7, 2022
    Date of Patent: November 12, 2024
    Assignee: Kioxia Corporation
    Inventors: Hidehiro Shiga, Daisaburo Takashima
  • Patent number: 12125545
    Abstract: A semiconductor memory device includes a driver that, in a write operation, applies a first voltage to a first select gate line, applies a second voltage lower than the first voltage to a second select gate line, applies a third voltage equal to or higher than the first voltage to a first dummy word line on an uppermost layer, applies a fourth voltage different from the third voltage and higher than the second voltage to a second dummy word line on an uppermost layer, applies a fifth voltage equal to or higher than the third voltage to a first dummy word line on a lowermost layer, and applies a sixth voltage different from the fifth voltage and equal to or higher than the fourth voltage to a second dummy word line on a lowermost layer.
    Type: Grant
    Filed: March 8, 2022
    Date of Patent: October 22, 2024
    Assignee: Kioxia Corporation
    Inventors: Reiko Sumi, Takashi Maeda, Hidehiro Shiga
  • Publication number: 20240321352
    Abstract: According to one embodiment, a device includes: a memory cell coupled to a bit line and configured to store first data including first, second, and third bits; and a sense amplification circuit configured to perform a first comparison between a bit line voltage and a first reference voltage, and a second comparison between the bit line voltage and a second reference voltage lower than the first reference voltage, and to read the first data from the memory cell based on results of the first and second comparisons. The sense amplification circuit is configured to retain second data having a first code in response to the bit line voltage becoming equal to or lower than the first reference voltage during a first period from a start of operation to a first time point, and retain the first data after the first period.
    Type: Application
    Filed: March 13, 2024
    Publication date: September 26, 2024
    Applicant: Kioxia Corporation
    Inventors: Ryu OGIWARA, Hidehiro SHIGA, Daisaburo TAKASHIMA
  • Publication number: 20240311286
    Abstract: An information processing apparatus that detects whether the corresponding first element and second element among the multiple first elements and the plurality of second elements are matched or are similar, has one or multiple strings connected to a first wiring and connected to multiple second wirings, wherein the string includes multiple transistor pairs connected in series along a current path having one end connected to the first wiring, each of the multiple transistor pairs includes a first transistor and a second transistor connected in series along the current path, the second wirings are connected to gates of the first transistor and the second transistor in each of the multiple transistor pairs, the first transistor is set to a first threshold depending on first data, the second transistor is set to a second threshold depending on second data that is complement data of the first data.
    Type: Application
    Filed: March 11, 2024
    Publication date: September 19, 2024
    Applicant: Kioxia Corporation
    Inventors: Atsushi KAWASUMI, Takashi MAEDA, Hidehiro SHIGA
  • Publication number: 20240304257
    Abstract: A semiconductor memory device includes first and second semiconductor pillars, a first string including first memory cells connected in series and a second string including second memory cells connected in series on opposite sides of the first semiconductor pillar, respectively, a third string including third memory cells connected in series and a fourth string including fourth memory cells connected in series, on opposite sides of the second semiconductor pillar, respectively, first word lines, second word lines, and a driver configured to supply different voltages to the first and second word lines during an erasing operation to erase data in the second and fourth memory cells. In the erasing operation, the driver supplies a first voltage higher than a reference voltage to the first word lines, and supplies the reference voltage to the second word lines.
    Type: Application
    Filed: February 28, 2024
    Publication date: September 12, 2024
    Inventors: Yuki INUZUKA, Hidehiro SHIGA
  • Patent number: 12068031
    Abstract: A semiconductor storage device includes a memory cell array including a plurality of word line groups and a plurality of blocks corresponding to the plurality of word line groups. Each of word line groups includes a plurality of word lines and each of the blocks includes a plurality of memory cells. The plurality of memory cells of each block are connected to the respective word lines of a corresponding one of the word line groups. The semiconductor storage device includes a row decoder including a plurality of word line group decoders corresponding to the plurality of word line groups, respectively. Each of the plurality of word line group decoders is configured to drive a word line independent from a word line driven in another of the word line groups, when all of the plurality of word line groups are activated in parallel.
    Type: Grant
    Filed: September 1, 2022
    Date of Patent: August 20, 2024
    Assignee: KIOXIA CORPORATION
    Inventors: Jun Deguchi, Daisuke Miyashita, Atsushi Kawasumi, Hidehiro Shiga, Shinji Miyano, Shinichi Sasaki
  • Publication number: 20240244839
    Abstract: A memory system for low power consumption and high speed read operation in the memory system includes a source line, a string select line having i layers, a first word line having i layers, a second word line having i layers, a select gate line having 1 layer which is divided into 2n, a plurality of memory pillars and a control circuit. Each of the plurality of memory pillars includes a first string and a second string. The first string includes a first transistor, i first memory cells and j second memory cells. The first transistor, the i first memory cells, and the j second memory cells are electrically connected in series. The second string includes a second transistor, i third memory cells, and j fourth memory cells. The second transistor, the i third memory cells, and the j fourth memory cells are electrically connected in series.
    Type: Application
    Filed: February 7, 2024
    Publication date: July 18, 2024
    Applicant: Kioxia Corporation
    Inventors: Kazutaka IKEGAMI, Hidehiro SHIGA, Shingo NAKAZAWA
  • Patent number: 11972798
    Abstract: A nonvolatile memory includes a first memory cell and a second memory cell above the first memory cell. The first memory cell includes a variable resistance layer extending in a first direction, a semiconductor layer extending in the first direction and in contact with the variable resistance layer, an insulator layer extending in the first direction and in contact with the semiconductor layer, and a first voltage applying electrode extending in a second direction and in contact with the insulator layer. The second memory cell includes a second voltage applying electrode in contact with the insulator layer. When a write operation is performed on the first memory cell, a first voltage is applied to the second voltage applying electrode, and when a write operation is performed on the second memory cell, a second voltage, lower than the first voltage, is applied to the first voltage applying electrode.
    Type: Grant
    Filed: February 25, 2022
    Date of Patent: April 30, 2024
    Assignee: Kioxia Corporation
    Inventors: Tomoki Chiba, Daisaburo Takashima, Hidehiro Shiga
  • Patent number: 11972797
    Abstract: A memory device includes a memory cell array including a select transistor and a plurality of memory cells connected in series, each memory cell including a cell transistor and a variable resistance layer connected in parallel. During a write operation, a voltage setting circuit is controlled to apply a first voltage to a selected word line and a second voltage to non-selected word lines. The time period for applying the first voltage to the selected word line starts later than the time period for applying the second voltage to the non-selected word lines and ends earlier than the time period for applying the second voltage to the non-selected word lines.
    Type: Grant
    Filed: February 24, 2022
    Date of Patent: April 30, 2024
    Assignee: Kioxia Corporation
    Inventors: Hidehiro Shiga, Daisaburo Takashima
  • Patent number: 11967371
    Abstract: A semiconductor memory device includes i first word lines connected to the i first memory cells, i second word lines connected to the i second memory cells, a driver capable of supplying voltage to each of the i first word lines and each of the i second word lines, and a logic control circuit controlling both a write operation including a verify operation and a read operation including a verify operation. In the semiconductor memory device, when an order of performing a sense operation for determining whether or not a threshold voltage of the k-th first memory cell has reached a j-th threshold voltage in the verify operation is different from that of in the read operation, a voltage applied to the k-th first word line in the verify operation is different from a voltage applied to the k-th first word line in the read operation.
    Type: Grant
    Filed: June 10, 2022
    Date of Patent: April 23, 2024
    Assignee: Kioxia Corporation
    Inventors: Rieko Funatsuki, Takashi Maeda, Hidehiro Shiga
  • Patent number: 11955176
    Abstract: A nonvolatile semiconductor storage device includes first and second semiconductor layers extending in a first direction and spaced apart in a second direction, first and second bit lines extending in the second direction and respectively arranged on opposite sides of the semiconductor layers in the first direction, first and second source lines extending in a third direction and respectively arranged on opposite sides of the semiconductor layers in the first direction, a first memory string including first and second select transistors connected to the first bit line and the first source line, respectively, a second memory string including third and fourth select transistors connected to the second bit line and the second source line, respectively, a first select gate line connected to gates of the first and fourth select transistors, and a second select gate line connected to gates of the second and third select transistors.
    Type: Grant
    Filed: August 27, 2021
    Date of Patent: April 9, 2024
    Assignee: Kioxia Corporation
    Inventor: Hidehiro Shiga
  • Publication number: 20240096413
    Abstract: A control circuit of a semiconductor memory device performs a write operation on a memory cell transistor of the semiconductor memory device by performing a first pulse application operation of lowering a threshold voltage of the memory cell transistor, a precharge operation, and then a second pulse application operation. In the precharge operation, in a state in which first and second select transistors connected to the memory cell transistor are turned on, a bit line connected to the memory cell transistor is charged by applying a ground voltage to a word line connected to a gate of the memory cell transistor and applying a voltage higher than the ground voltage to a source line. In the second pulse application operation, in a state in which the first select transistor is turned on and the second select transistor is turned off, a program voltage is applied to the word line.
    Type: Application
    Filed: March 2, 2023
    Publication date: March 21, 2024
    Inventors: Natsuki SAKAGUCHI, Takashi MAEDA, Rieko FUNATSUKI, Hidehiro SHIGA
  • Publication number: 20240071477
    Abstract: A memory system for speeding up a read operation in the memory system includes a first pillar, a first string including a first transistor and a first memory cell, a second string including a second transistor and a second memory cell, a first bit line, a first gate line, a first word line, a second gate line, a second word line and a control circuit. When the control circuit executes a read operation with respect to the first memory cell, the control circuit is configured to apply a read voltage to the first word line, apply a voltage turning off the second memory cell regardless of an electric charge stored in the second memory cell to the second word line, apply a voltage turning on the first transistor to the first gate line, and apply a voltage turning on the second transistor to the second gate line.
    Type: Application
    Filed: November 2, 2023
    Publication date: February 29, 2024
    Applicant: Kioxia Corporation
    Inventors: Kazutaka IKEGAMI, Rieko FUNATSUKI, Nobuyuki MOMO, Hidehiro SHIGA
  • Patent number: 11901011
    Abstract: A semiconductor storage device includes a first word line, a second word line provided in the same layer with the first word line and configured to be controlled independently from the first word line, a plurality of memory pillars between the first word line and the second word line, each of the plurality of memory pillars including a first memory cell facing to the first word line and a second memory cell facing to the second word line, the plurality of memory pillars being arranged in a first direction and a second direction intersecting to the first direction and a control circuit. The control circuit is configured to perform a write operation to the second memory cell included in the plurality of memory pillars after performing a write operation to the first memory cell included in each of the plurality of memory pillars.
    Type: Grant
    Filed: August 11, 2021
    Date of Patent: February 13, 2024
    Assignee: Kioxia Corporation
    Inventors: Kazutaka Ikegami, Hidehiro Shiga
  • Publication number: 20240049479
    Abstract: A variable resistance non-volatile memory includes a memory cell including a core portion extending in a first direction above a semiconductor substrate, a variable resistance layer extending in a first direction and in contact with the core portion, a semiconductor layer extending in a first direction and in contact with the variable resistance layer, an insulator layer extending in a first direction and in contact with the semiconductor layer, and a first voltage application electrode extending in a second direction crossing the first direction and in contact with the insulator layer. An impurity concentration of the semiconductor layer is non-uniform, such that an impurity concentration of a first portion of the semiconductor layer in contact with the insulator layer is at least ten times higher than an impurity concentration of a second portion of the semiconductor layer in contact with the variable resistance layer.
    Type: Application
    Filed: March 1, 2023
    Publication date: February 8, 2024
    Inventors: Yuki ITO, Daisaburo TAKASHIMA, Hidehiro SHIGA, Yoshiki KAMATA
  • 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: 20240005997
    Abstract: Disclosed herein are related to a memory device and a method of operating the memory device. In one aspect, a voltage supply circuit is configured to apply, during a first time period, a first voltage to a gate of a first switch transistor connected to a first block of memory cells through a first word line to enable the first switch transistor. In one aspect, the voltage supply circuit is configured to apply, during the first time period, a second voltage lower than the first voltage to the first word line through the first switch transistor. In one aspect, the voltage supply circuit is configured to apply, during the first time period, a third voltage lower than the second voltage to a gate of a second switch transistor connected to a second block of memory cells through a second word line to disable the second switch transistor.
    Type: Application
    Filed: March 9, 2023
    Publication date: January 4, 2024
    Applicant: Kioxia Corporation
    Inventor: Hidehiro SHIGA