Patents by Inventor Daisuke Kouno
Daisuke Kouno 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).
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Patent number: 9928915Abstract: 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: GrantFiled: October 21, 2016Date of Patent: March 27, 2018Assignee: TOSHIBA MEMORY CORPORATIONInventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Publication number: 20170040062Abstract: 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: ApplicationFiled: October 21, 2016Publication date: February 9, 2017Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yasuhiro SHIINO, Daisuke KOUNO, Shigefumi IRIEDA, Kenri NAKAI, Eietsu TAKAHASHI
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Patent number: 9508442Abstract: 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: GrantFiled: January 7, 2016Date of Patent: November 29, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Publication number: 20160118127Abstract: 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: ApplicationFiled: January 7, 2016Publication date: April 28, 2016Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Patent number: 9263140Abstract: 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: GrantFiled: May 15, 2014Date of Patent: February 16, 2016Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Patent number: 8848447Abstract: 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: GrantFiled: September 7, 2011Date of Patent: September 30, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Publication number: 20140254282Abstract: 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: ApplicationFiled: May 15, 2014Publication date: September 11, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yasuhiro SHIINO, Daisuke KOUNO, Shigefumi IRIEDA, Kenri NAKAI, Eietsu TAKAHASHI
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Patent number: 8767478Abstract: 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: GrantFiled: July 15, 2013Date of Patent: July 1, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Publication number: 20130301359Abstract: 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: ApplicationFiled: July 15, 2013Publication date: November 14, 2013Inventors: Yasuhiro SHIINO, Daisuke KOUNO, Shigefumi IRIEDA, Kenri NAKAI, Eietsu TAKAHASHI
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Patent number: 8531891Abstract: 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: GrantFiled: January 10, 2012Date of Patent: September 10, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Publication number: 20120281477Abstract: 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: ApplicationFiled: December 1, 2011Publication date: November 8, 2012Inventors: Manabu Sakaniwa, Koki Ueno, Shigefumi Irieda, Eietsu Takahashi, Yasuhiro Shiino, Daisuke Kouno
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Publication number: 20120106257Abstract: 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: ApplicationFiled: January 10, 2012Publication date: May 3, 2012Applicant: Kabushiki Kaisha ToshibaInventors: Yasuhiro SHIINO, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Patent number: 8149631Abstract: 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: GrantFiled: June 9, 2010Date of Patent: April 3, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhiro Shiino, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Publication number: 20120072648Abstract: 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: ApplicationFiled: September 7, 2011Publication date: March 22, 2012Applicant: Kabushiki Kaisha ToshibaInventors: Yasuhiro SHIINO, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi
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Publication number: 20110013461Abstract: 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: ApplicationFiled: June 9, 2010Publication date: January 20, 2011Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yasuhiro SHIINO, Daisuke Kouno, Shigefumi Irieda, Kenri Nakai, Eietsu Takahashi