Patents by Inventor Toshifumi Shano

Toshifumi Shano 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: 9947408
    Abstract: A semiconductor memory device includes a block of memory cells including first, second, and third memory cells, a first word line electrically connected to a gate of the first memory cell, a second word line electrically connected to a gate of the second memory cell, a third word line electrically connected to a gate of the third memory cell, and a control circuit configured to access the block in one of at least first and second modes to perform an operation thereon. When the control circuit accesses the block in the first mode, the same voltage is applied to the first and second word lines throughout the operation, and when the control circuit accesses the block in the second mode, the same voltage is applied to the second and third word lines throughout the operation.
    Type: Grant
    Filed: February 26, 2016
    Date of Patent: April 17, 2018
    Assignee: Toshiba Memeory Corporation
    Inventors: Toshifumi Shano, Masanobu Shirakawa, Tokumasa Hara
  • Publication number: 20160260483
    Abstract: A semiconductor memory device includes a block of memory cells including first, second, and third memory cells, a first word line electrically connected to a gate of the first memory cell, a second word line electrically connected to a gate of the second memory cell, a third word line electrically connected to a gate of the third memory cell, and a control circuit configured to access the block in one of at least first and second modes to perform an operation thereon. When the control circuit accesses the block in the first mode, the same voltage is applied to the first and second word lines throughout the operation, and when the control circuit accesses the block in the second mode, the same voltage is applied to the second and third word lines throughout the operation.
    Type: Application
    Filed: February 26, 2016
    Publication date: September 8, 2016
    Inventors: Toshifumi SHANO, Masanobu SHIRAKAWA, Tokumasa HARA
  • Patent number: 9299438
    Abstract: According to one embodiment, a semiconductor memory device includes a first string; a second string; and a controller. The first string is coupled with a first bit line and includes first memory cells. The second string is coupled with a second bit line and includes second memory cells. The controller executes writing first data into the first memory cells and writing second data into the second memory cells simultaneously. The controller reads data from the first and second strings after writing the first and second data.
    Type: Grant
    Filed: September 17, 2013
    Date of Patent: March 29, 2016
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tokumasa Hara, Naoya Tokiwa, Hiroshi Sukegawa, Hitoshi Iwai, Toshifumi Shano, Shirou Fujita
  • Patent number: 9177661
    Abstract: According to one embodiment, a semiconductor memory device reads data in units of page. The device includes: a memory cell array; a plurality of latch circuits; and an arithmetic operation circuit. The memory cell array holds data multiplexed in at least three pages. The latch circuits read and hold the multiplexed data at a startup. The arithmetic operation circuit performs operations by use of the multiplexed data.
    Type: Grant
    Filed: December 27, 2013
    Date of Patent: November 3, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Tokumasa Hara, Naoya Tokiwa, Hiroshi Sukegawa, Hitoshi Iwai, Toshifumi Shano, Shirou Fujita
  • Patent number: 9165655
    Abstract: A nonvolatile semiconductor memory device comprises multiple memory strings each including a plurality of first and second groups of serially connected memory cells, and a back gate transistor serially connected between the first and second groups of memory cells, a plurality of word lines, each word line being connected to a control gate of a different memory cell in each of the memory strings, a voltage generating circuit configured to generate control voltages of different voltage levels, and a control circuit configured to control application of control voltages to the word lines and the back gate line. A control voltage applied to the back gate line may be varied depending on how far a selected word line is from the back gate line, and a control voltage applied to unselected word lines may be varied depending on how far the unselected word line is from the selected word line.
    Type: Grant
    Filed: August 25, 2014
    Date of Patent: October 20, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Toshifumi Shano
  • Publication number: 20150036434
    Abstract: According to one embodiment, a semiconductor memory device reads data in units of page. The device includes: a memory cell array; a plurality of latch circuits; and an arithmetic operation circuit. The memory cell array holds data multiplexed in at least three pages. The latch circuits read and hold the multiplexed data at a startup. The arithmetic operation circuit performs operations by use of the multiplexed data.
    Type: Application
    Filed: December 27, 2013
    Publication date: February 5, 2015
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Tokumasa HARA, Naoya Tokiwa, Hiroshi Sukegawa, Hitoshi Iwai, Toshifumi Shano, Shirou Fujita
  • Publication number: 20150016190
    Abstract: A nonvolatile semiconductor memory device comprises multiple memory strings each including a plurality of first and second groups of serially connected memory cells, and a back gate transistor serially connected between the first and second groups of memory cells, a plurality of word lines, each word line being connected to a control gate of a different memory cell in each of the memory strings, a voltage generating circuit configured to generate control voltages of different voltage levels, and a control circuit configured to control application of control voltages to the word lines and the back gate line. A control voltage applied to the back gate line may be varied depending on how far a selected word line is from the back gate line, and a control voltage applied to unselected word lines may be varied depending on how far the unselected word line is from the selected word line.
    Type: Application
    Filed: August 25, 2014
    Publication date: January 15, 2015
    Inventors: Koji HOSONO, Toshifumi SHANO
  • Publication number: 20140369127
    Abstract: According to one embodiment, a semiconductor memory device includes a first string; a second string; and a controller. The first string is coupled with a first bit line and includes first memory cells. The second string is coupled with a second bit line and includes second memory cells. The controller executes writing first data into the first memory cells and writing second data into the second memory cells simultaneously. The controller reads data from the first and second strings after writing the first and second data.
    Type: Application
    Filed: September 17, 2013
    Publication date: December 18, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Tokumasa HARA, Naoya Tokiwa, Hiroshi Sukegawa, Hitoshi Iwai, Toshifumi Shano, Shirou Fujita
  • Patent number: 8854896
    Abstract: A nonvolatile semiconductor memory device comprises multiple memory strings each including a plurality of first and second groups of serially connected memory cells, and a back gate transistor serially connected between the first and second groups of memory cells, a plurality of word lines, each word line being connected to a control gate of a different memory cell in each of the memory strings, a voltage generating circuit configured to generate control voltages of different voltage levels, and a control circuit configured to control application of control voltages to the word lines and the back gate line. A control voltage applied to the back gate line may be varied depending on how far a selected word line is from the back gate line, and a control voltage applied to unselected word lines may be varied depending on how far the unselected word line is from the selected word line.
    Type: Grant
    Filed: March 5, 2013
    Date of Patent: October 7, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Koji Hosono, Toshifumi Shano
  • Publication number: 20140098612
    Abstract: A nonvolatile semiconductor memory device comprises multiple memory strings each including a plurality of first and second groups of serially connected memory cells, and a back gate transistor serially connected between the first and second groups of memory cells, a plurality of word lines, each word line being connected to a control gate of a different memory cell in each of the memory strings, a voltage generating circuit configured to generate control voltages of different voltage levels, and a control circuit configured to control application of control voltages to the word lines and the back gate line. A control voltage applied to the back gate line may be varied depending on how far a selected word line is from the back gate line, and a control voltage applied to unselected word lines may be varied depending on how far the unselected word line is from the selected word line.
    Type: Application
    Filed: March 5, 2013
    Publication date: April 10, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Koji HOSONO, Toshifumi SHANO
  • Patent number: 7613048
    Abstract: A nonvolatile semiconductor memory device including a memory cell array including a plurality of electrically rewritable nonvolatile memory cells arranged in series, the memory cell storing data using a plurality of threshold levels, a threshold level storage section storing a programming method switch threshold level on which a first programming method and a second programming method are switched, a comparison circuit comparing the programming method switch threshold level with a programming data threshold level and outputting a comparison result, a control signal generation circuit setting the first programming method or the second programming method based on the comparison result and outputting a control signal corresponding to the first programming method or the second programming method and a voltage generation circuit generating a programming voltage and an intermediate voltage which are applied to the memory cell based on the control signal.
    Type: Grant
    Filed: November 2, 2007
    Date of Patent: November 3, 2009
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Atsushi Inoue, Toshifumi Shano
  • Publication number: 20080106946
    Abstract: A nonvolatile semiconductor memory device including a memory cell array including a plurality of electrically rewritable nonvolatile memory cells arranged in series, the memory cell storing data using a plurality of threshold levels, a threshold level storage section storing a programming method switch threshold level on which a first programming method and a second programming method are switched, a comparison circuit comparing the programming method switch threshold level with a programming data threshold level and outputting a comparison result, a control signal generation circuit setting the first programming method or the second programming method based on the comparison result and outputting a control signal corresponding to the first programming method or the second programming method and a voltage generation circuit generating a programming voltage and an intermediate voltage which are applied to the memory cell based on the control signal.
    Type: Application
    Filed: November 2, 2007
    Publication date: May 8, 2008
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Atsushi INOUE, Toshifumi Shano