Patents by Inventor Yasuhiro Shiino

Yasuhiro Shiino 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).

  • Publication number: 20150213903
    Abstract: A nonvolatile semiconductor memory device according to one embodiment of the present invention includes: a memory cell array and a control circuit. The control circuit executes a first reading operation and a second reading operation. The first reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between a control gate electrode and source of the selected memory cell to a first value. The second reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between the control gate electrode and source of the selected memory cell to a second value lower than the first value. When executing the second reading operation, the control circuit keeps a voltage of the control gate electrode of the selected memory cell to 0 or a positive value.
    Type: Application
    Filed: April 2, 2015
    Publication date: July 30, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yasuhiro SHIINO, Eietsu TAKAHASHI, Koki UENO
  • Patent number: 9064598
    Abstract: A nonvolatile semiconductor memory device according to one embodiment comprises: a memory cell array comprising a plurality of NAND strings, each NAND string comprising a memory string comprising a plurality of memory cells and a dummy transistor; a plurality of word lines; a dummy word line; a plurality of bit lines; a source line; and a control circuit performing an erase sequence, the erase sequence repeating an erase operation to the memory cells and the dummy transistor and an erase verify operation of confirming whether the memory cells and the dummy transistor are changed to an erased state. The control circuit is configured to be able to perform, when the erase verify operation is unpassed, a dummy transistor erase operation of selectively changing the dummy transistor to an erased state and a dummy transistor erase verify operation of confirming whether the dummy transistor is changed to an erased state.
    Type: Grant
    Filed: May 29, 2014
    Date of Patent: June 23, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryota Hirai, Yasuhiro Shiino
  • Patent number: 9047958
    Abstract: A non-volatile semiconductor memory device according to one embodiment includes: a cell array; and a data writing unit that repeatedly executes a write loop including a programming operation of applying a program voltage to a selected word line and a passage voltage to non-selected word lines during writing of data, in which, when a difference between the passage voltage used in an n-th write loop and the passage voltage used in an n+1-th write loop is expressed as ?Vn and when a condition of L<M (L and M are integers) is satisfied, the data writing unit executes the write loop using the passage voltage where ?V(L?1)<?VL, ?VL??V(M?1), and ?V(M?1)<?VM.
    Type: Grant
    Filed: December 7, 2012
    Date of Patent: June 2, 2015
    Assignee: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yasuhiro Shiino, Shigefumi Irieda
  • Patent number: 9025387
    Abstract: A nonvolatile semiconductor memory device according to one embodiment of the present invention includes: a memory cell array and a control circuit. The control circuit executes a first reading operation and a second reading operation. The first reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between a control gate electrode and source of the selected memory cell to a first value. The second reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between the control gate electrode and source of the selected memory cell to a second value lower than the first value. When executing the second reading operation, the control circuit keeps a voltage of the control gate electrode of the selected memory cell to 0 or a positive value.
    Type: Grant
    Filed: November 25, 2013
    Date of Patent: May 5, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Eietsu Takahashi, Koki Ueno
  • Publication number: 20150070986
    Abstract: A nonvolatile semiconductor memory device according to an embodiment includes: a memory cell array configured having NAND strings arranged therein; a plurality of word lines; a plurality of bit lines; a source line; and a control circuit configured to apply a verify voltage to a selected word line, apply a read pass voltage that renders conductive an unselected memory cell regardless of cell data to an unselected word line, and apply a bit line voltage of a certain value to a selected bit line, thereby executing a write verify operation that determines whether a selected memory cell has a desired threshold voltage or not. The control circuit is configured capable of changing a voltage value of the bit line voltage based on a position of the selected word line among the plurality of word lines relative to the NAND string.
    Type: Application
    Filed: December 23, 2013
    Publication date: March 12, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Ryota HIRAI, Yasuhiro SHIINO
  • Patent number: 8976597
    Abstract: A control circuit executes an erase operation that includes an erase pulse application operation and an erase verify operation. The erase pulse application operation applies an erase pulse voltage to a memory cell to change the memory cell from a write state to an erase state. The erase verify operation applies an erase verify voltage to the memory cell to judge whether the memory cell is in the erase state or not. The control circuit changes conditions of execution of the erase verify operation when the number of times of executions of the erase pulse application operation in one erase operation reaches a first number.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: March 10, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Eietsu Takahashi, Koki Ueno
  • Patent number: 8953371
    Abstract: A semiconductor storage device has a plurality of memory cells each having a control gate that are formed on a well. The semiconductor storage device has a control circuit that applies a voltage to the well and the control gates. In an erase operation of the memory cell, the control circuit applies a first pulse wave of a first erasure voltage that rises stepwise to the well and then applies a second pulse wave of a second erasure voltage to the well.
    Type: Grant
    Filed: March 20, 2012
    Date of Patent: February 10, 2015
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi, Koki Ueno
  • Publication number: 20150035800
    Abstract: According to an embodiment, an information terminal apparatus includes: a display device equipped with a touch panel; a position detecting section configured to detect a position of a material body in a three-dimensional space opposite to a display surface of the display device; and a command generating section configured to generate a predetermined command for causing predetermined processing to be executed, on the basis of touch position information of a touch position on the touch panel by a touch operation on the touch panel and position-in-space information of the material body in the three-dimensional space detected by the position detecting section after the touch panel is touched or in a state of the touch panel being touched.
    Type: Application
    Filed: March 6, 2014
    Publication date: February 5, 2015
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Mineharu Uchiyama, Yasuhiro Shiino, Mayuko Yoshida, Junya Suzuki, Keiichiro Mori, Hiroyuki Oka, Hideki Yagi, Yoshihiro Kato, Ai Matsui
  • Publication number: 20140340964
    Abstract: According to one embodiment, a nonvolatile semiconductor memory device includes a memory cell array and a control circuit configured to repeat a program operation and a verify operation. The control circuit performs a first verify operation of sensing whether threshold voltages of selected memory cells are greater than or equal to a first threshold voltage, and a second verify operation of sensing whether the threshold voltages of the selected memory cells are greater than or equal to a second threshold voltage (first threshold voltage<second threshold voltage), and the control circuit changes a charge voltage for the bit lines between the first verify operation and the second verify operation.
    Type: Application
    Filed: August 29, 2013
    Publication date: November 20, 2014
    Inventors: Yasuhiro SHIINO, Nobushi MATSUURA, Masashi YOSHIDA, Eietsu TAKAHASHI
  • Patent number: 8873298
    Abstract: A nonvolatile semiconductor storage device according to an embodiment includes: a memory cell array including plural memory cells; and a control circuit that repeatedly performs a write loop including a program operation and a verify operation in data write performed to the memory cell, the verify operation including a preverify step to check whether a threshold voltage of the memory cell transitions to a preverify voltage, and a real verify step to check whether the threshold voltage of the memory cell transitions to the real verify voltage, the write loop including one or at least two verify operations corresponding to pieces of the data, the control circuit performing the write loop in which the preverify step of the verify operation corresponding to a first data is omitted after obtaining a first condition.
    Type: Grant
    Filed: April 20, 2012
    Date of Patent: October 28, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Eietsu Takahashi
  • Patent number: 8848447
    Abstract: A nonvolatile semiconductor memory device in accordance with an embodiment includes: a memory cell array having electrically rewritable nonvolatile memory cells; and a control unit. The control unit performs control of repeating a write operation, a write verify operation, and a step-up operation, the write verify operation being an operation to verify whether data write is completed or not, and the step-up operation being an operation to raise the write pulse voltage if data write is not completed. The control unit, during the write operation, raises a first write pulse voltage with a first gradient, and then raises a second write pulse voltage with a second gradient, thereby executing the write operation, the first write pulse voltage including at least a write pulse voltage generated at first, the second write pulse voltage being generated after the first write pulse voltage, and the second gradient being larger than the first gradient.
    Type: Grant
    Filed: September 7, 2011
    Date of Patent: September 30, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
  • Publication number: 20140286100
    Abstract: A nonvolatile semiconductor memory device includes a control circuit configured to control a soft program operation of setting nonvolatile memory cells to a first threshold voltage distribution state of the nonvolatile memory cells. When a characteristic of the nonvolatile memory cells is in a first state, the control circuit executes the soft program operation by applying a first voltage for setting the nonvolatile memory cells to the first threshold voltage distribution state to first word lines, and applying a second voltage higher than the first voltage to a second word line. When the characteristic of the nonvolatile memory cells is in a second state, the control circuit executes the soft program operation by applying a third voltage equal to or lower than the first voltage to the first word lines and applying a fourth voltage lower than the second voltage to the second word line.
    Type: Application
    Filed: June 4, 2014
    Publication date: September 25, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yasuhiro SHIINO, Eietsu Takahashi
  • Publication number: 20140254282
    Abstract: For data erase from an electrically erasable and programmable non-volatile memory cell, the following operations are performed: an erase operation to apply an erase pulse voltage to a memory cell for data erase, an erase verify operation to verify whether data erase is completed, and a step-up operation to increase the erase pulse voltage by a certain step-up voltage if data erase is not completed. A control unit controls voltages so that at least a first erase pulse voltage initially generated in the erase operation has a longer rise time than that of a second erase pulse voltage generated subsequent to the first erase pulse voltage.
    Type: Application
    Filed: May 15, 2014
    Publication date: September 11, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Yasuhiro SHIINO, Daisuke KOUNO, Shigefumi IRIEDA, Kenri NAKAI, Eietsu TAKAHASHI
  • Publication number: 20140241058
    Abstract: According to an embodiment, a semiconductor memory device includes a memory cell array and a control circuit. The memory cell array comprises a plurality of memory cells that each include a control gate and a charge accumulation layer and that each are configured to have a threshold set to be included in any of a plurality of threshold distributions, the memory cell being connected between a bit line and a source line. The control circuit, in at least one of a write verify operation and a read operation on a selected memory cell, applies to the control gate a control gate voltage to determine the threshold of the selected memory cell, the control gate voltage having a plurality of values respectively corresponded to the plurality of threshold distributions, and sets a voltage between the bit line and the source line based on the control gate voltage.
    Type: Application
    Filed: September 4, 2013
    Publication date: August 28, 2014
    Applicant: KABUSHIKI KAISHA TOSHIBA
    Inventors: Masashi Yoshida, Eietsu Takahashi, Yasuhiro Shiino, Nobushi Matsuura
  • Patent number: 8787091
    Abstract: A nonvolatile semiconductor memory device includes a control circuit configured to control a soft program operation of setting nonvolatile memory cells to a first threshold voltage distribution state of the nonvolatile memory cells. When a characteristic of the nonvolatile memory cells is in a first state, the control circuit executes the soft program operation by applying a first voltage for setting the nonvolatile memory cells to the first threshold voltage distribution state to first word lines, and applying a second voltage higher than the first voltage to a second word line. When the characteristic of the nonvolatile memory cells is in a second state, the control circuit executes the soft program operation by applying a third voltage equal to or lower than the first voltage to the first word lines and applying a fourth voltage lower than the second voltage to the second word line.
    Type: Grant
    Filed: October 30, 2013
    Date of Patent: July 22, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Eietsu Takahashi
  • Patent number: 8767478
    Abstract: For data erase from an electrically erasable and programmable non-volatile memory cell, the following operations are performed: an erase operation to apply an erase pulse voltage to a memory cell for data erase, an erase verify operation to verify whether data erase is completed, and a step-up operation to increase the erase pulse voltage by a certain step-up voltage if data erase is not completed. A control unit controls voltages so that at least a first erase pulse voltage initially generated in the erase operation has a longer rise time than that of a second erase pulse voltage generated subsequent to the first erase pulse voltage.
    Type: Grant
    Filed: July 15, 2013
    Date of Patent: July 1, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
  • 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
  • Patent number: 8737134
    Abstract: A nonvolatile semiconductor storage device according to an embodiment includes a drive circuit. A voltage applied to a dummy wire connected to a first dummy cell adjacent to a memory string is defined as a first dummy wire voltage, a voltage applied to a selection wire connected to a first memory cell adjacent to the first dummy cell is defined as a first selection wire voltage, and a voltage applied to a selection wire connected to a second memory cell adjacent to the first memory cell is defined as a second selection wire voltage. When the second selection wire voltage is lower than the first dummy wire voltage in an erase operation, the drive circuit controls voltages so that a difference between the first dummy wire voltage and the second selection wire voltage is less than a difference between the first dummy wire voltage and the first selection wire voltage.
    Type: Grant
    Filed: March 12, 2012
    Date of Patent: May 27, 2014
    Assignee: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Eietsu Takahashi, Yuji Takeuchi
  • Publication number: 20140085988
    Abstract: A nonvolatile semiconductor memory device according to one embodiment of the present invention includes: a memory cell array and a control circuit. The control circuit executes a first reading operation and a second reading operation. The first reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between a control gate electrode and source of the selected memory cell to a first value. The second reading operation is an operation of reading a threshold voltage set in the selected memory cell by setting a voltage between the control gate electrode and source of the selected memory cell to a second value lower than the first value. When executing the second reading operation, the control circuit keeps a voltage of the control gate electrode of the selected memory cell to 0 or a positive value.
    Type: Application
    Filed: November 25, 2013
    Publication date: March 27, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Eietsu Takahashi, Koki Ueno
  • Publication number: 20140050027
    Abstract: A nonvolatile semiconductor memory device includes a control circuit configured to control a soft program operation of setting nonvolatile memory cells to a first threshold voltage distribution state of the nonvolatile memory cells. When a characteristic of the nonvolatile memory cells is in a first state, the control circuit executes the soft program operation by applying a first voltage for setting the nonvolatile memory cells to the first threshold voltage distribution state to first word lines, and applying a second voltage higher than the first voltage to a second word line. When the characteristic of the nonvolatile memory cells is in a second state, the control circuit executes the soft program operation by applying a third voltage equal to or lower than the first voltage to the first word lines and applying a fourth voltage lower than the second voltage to the second word line.
    Type: Application
    Filed: October 30, 2013
    Publication date: February 20, 2014
    Applicant: Kabushiki Kaisha Toshiba
    Inventors: Yasuhiro Shiino, Eietsu Takahashi