Patents by Inventor Takayuki Tsukamoto
Takayuki Tsukamoto 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: 9202564Abstract: A control circuit is configured to perform a state determination operation to sense voltages of a plurality of first wiring lines, the voltages changing based on current flowing from the first wiring lines to a plurality of second wiring lines via a plurality of variable resistive elements. Then, the control circuit is configured to adjust voltages to be applied to the first and second wiring lines in a reset operation or a set operation based on the voltages of the first wiring lines sensed in the state determination operation.Type: GrantFiled: September 11, 2013Date of Patent: December 1, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yoichi Minemura, Takayuki Tsukamoto, Hiroshi Kanno, Takamasa Okawa
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Patent number: 9202533Abstract: A nonvolatile semiconductor memory device comprises: a memory cell array including first interconnections, second interconnections intersecting the first interconnections, and memory cells having a variable resistance element and being provided at respective intersections of the first interconnections and the second interconnections, the memory cell array being divided into bays including a predetermined number of the memory cells; and a control circuit configured to execute a first write step and a second write step executed after the first write step at a data writing operation, wherein the control circuit is configured to change over the number of simultaneously selected bits and/or the number of simultaneously selected bays depending upon whether a write step is the first write step or the second write step.Type: GrantFiled: January 16, 2014Date of Patent: December 1, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Hideyuki Tabata, Takayuki Tsukamoto
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Patent number: 9190147Abstract: A memory cell array comprises memory cells disposed at intersections of a plurality of first lines disposed in parallel and a plurality of second lines disposed intersecting the first lines. The memory cell includes a variable resistance element. A set operation-dedicated first driver circuit, when executing on the memory cell a set operation for switching a memory cell from a high-resistance state to a low-resistance state, supplies a voltage to the first lines. A reset operation-dedicated first driver circuit, when executing on the memory cell a reset operation for switching the memory cell from a low-resistance state to a high-resistance state, supplies a voltage to the first lines. A length of a wiring line between the set operation-dedicated first driver circuit and the memory cell array is longer compared to a length of a wiring line between the reset operation-dedicated first driver circuit and the memory cell array.Type: GrantFiled: August 19, 2013Date of Patent: November 17, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yoichi Minemura, Takayuki Tsukamoto, Hiroshi Kanno, Takamasa Okawa
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Patent number: 9142290Abstract: According to one embodiment, a nonvolatile memory device includes: a memory cell array including first wirings, second wirings, and a memory cell connected between the first wirings and the second wirings; and a control circuit unit configured to select a selected memory cell from the memory cells, perform a first operation of changing a resistance state of the selected memory cell between a first resistance state and a second resistance state, and determine whether the first operation has been properly performed or not and perform retry operation such as applying a retry pulse when the first operation has not been properly performed. The control circuit unit regards the selected memory cell as excessive retry operation and inhibits the selected memory cell in accordance with the number of times of the excessive retry operation when the number of times of the retry operation is over k times.Type: GrantFiled: November 13, 2013Date of Patent: September 22, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Hiroshi Kanno, Yoichi Minemura, Takayuki Tsukamoto, Takamasa Okawa, Atsushi Yoshida
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Publication number: 20150263278Abstract: A memory device according to an embodiment, includes a selection element, a first interconnection provided in a first direction when viewed from the selection element and extending in the first direction, a plurality of second interconnections provided in a second direction crossing the first direction when viewed from the first interconnection and arranged in the first direction, a memory element provided between the first interconnection and the second interconnection, and a high resistance component connected between the selection element and the first interconnection and having a resistivity higher than a resistivity of the first interconnection and a resistivity of the second interconnection.Type: ApplicationFiled: September 19, 2014Publication date: September 17, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Hiroyuki ODE, Takeshi YAMAGUCHI, Shigeki KOBAYASHI, Masaki YAMATO, Yoshinori NAKAKUBO, Takeshi TAKAGI, Takayuki TSUKAMOTO
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Patent number: 9117516Abstract: According to one embodiment, a memory includes memory cells between first conductive lines and second conductive lines. A control circuit is configured to apply a first potential to a first end of a selected first conductive line connected to the selected memory cell among the first conductive lines and first ends of unselected second conductive lines not connected to the selected memory cell among the second conductive lines, apply a second potential larger than the first potential to a first end of a selected second conductive line connected to the selected memory cell among the second conductive lines, apply third potentials smaller than the second potential to first ends of unselected first conductive lines not connected to the selected memory cell among the first conductive lines respectively, and change values of the third potentials based on an address of the selected first conductive line.Type: GrantFiled: September 5, 2013Date of Patent: August 25, 2015Assignees: KABUSHIKI KAISHA TOSHIBA, SanDisk CorporationInventors: Takamasa Okawa, Fumitoshi Ito, Youichi Minemura, Takayuki Tsukamoto, Hiroshi Kanno
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Publication number: 20150228337Abstract: A semiconductor memory device comprises: first lines disposed in a first direction perpendicular to a substrate and extending in a second direction parallel to the substrate; second lines disposed in the second direction and configured to extend in the first direction, the second lines intersecting the first lines; and memory cells disposed at intersections of the first lines and the second lines and each including a variable resistance element. Furthermore, a third line extends in a third direction orthogonal to the first and second directions. A select transistor is connected between the second and third lines. A control circuit controls a voltage applied to the first and third lines, and the select transistor. The control circuit renders conductive at least one of the select transistors and thereby detect a current flowing in the third line, and determines a deterioration state of the select transistor according to a detection result.Type: ApplicationFiled: June 17, 2014Publication date: August 13, 2015Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Takamasa OKAWA, Takayuki Tsukamoto, Yoichi Minemura, Hiroshi Kanno, Atsushi Yoshida, Hideyuki Tabata
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Publication number: 20150221368Abstract: A semiconductor memory device according to an embodiment includes a memory cell array and a control circuit. The memory cell array includes: a plurality of first conductive layers that are stacked; a memory layer provided on a side surface of the plurality of the first conductive layers; and a second conductive layer that contacts the side surface of the plurality of the first conductive layers via the memory layer. A thickness of the first conductive layer disposed at the first position is larger than a thickness of the first conductive layer disposed at the second position. The control circuit is configured to apply a first voltage to a selected first conductive layer. The control circuit changes a value of the first voltage based on a position of the selected first conductive layer.Type: ApplicationFiled: June 16, 2014Publication date: August 6, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Hiroshi KANNO, Takayuki TSUKAMOTO, Takamasa OKAWA, Atsushi YOSHIDA
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Patent number: 9099180Abstract: According to one embodiment, a semiconductor memory device includes a plurality of cell array blocks and a control circuit. The control circuit sets a selected bit line to have 0 volt, applies a first electric potential which is higher than 0 volt to a selected word line, applies a second electric potential which is higher than 0 volt and lower than the first electric potential to non-selected word lines other than the selected word line, applies a third electric potential which is 0 volt or more and lower than the second electric potential to a non-selected bit line adjacent to the selected bit line in an adjacent cell array block, applies the second electric potential to non-selected bit lines other than the non-selected bit line to which the third electric potential is applied, and changes a resistance status of the resistance variable film of the selected memory cell.Type: GrantFiled: August 30, 2012Date of Patent: August 4, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Yoichi Minemura, Takayuki Tsukamoto, Takafumi Shimotori, Hiroshi Kanno, Tomonori Kurosawa, Mizuki Kaneko
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Patent number: 9093144Abstract: A control circuit is configured to perform, when a plurality of variable resistance elements connected to a selected first wiring line are selected, a read operation to sense a voltage of the selected first wiring line. The control circuit is configured to adjust, according to the voltage of the selected first wiring line sensed in the read operation, a voltage to be applied to the selected first wiring line in a reset operation or a set operation. The reset operation is an operation to increase resistance of a variable resistance element. The set operation is an operation to decrease resistance of a variable resistance element.Type: GrantFiled: September 13, 2013Date of Patent: July 28, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Hiroshi Kanno, Yoichi Minemura, Takayuki Tsukamoto
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Patent number: 9076525Abstract: A semiconductor storage device includes a memory cell array, and a control circuit. The memory cell array has memory cells including variable resistive elements disposed at intersections of a plurality of first lines and a plurality of second lines. The control circuit performs a set pulse applying operation, and a cure pulse applying operation. The set pulse applying operation applies a set pulse to a variable resistive element so as to cause the variable resistive element to transition from a high resistance state to a low resistance state. The cure pulse applying operation applies a cure pulse to the variable resistive element. The cure pulse has a polarity that is opposite of a polarity of the set pulse, and is larger than the set pulse.Type: GrantFiled: August 29, 2012Date of Patent: July 7, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Mizuki Kaneko, Tomonori Kurosawa, Yoichi Minemura, Hiroshi Kanno, Takafumi Shimotori, Takayuki Tsukamoto
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Publication number: 20150179704Abstract: A semiconductor memory device according to an embodiment described below comprises: first lines arranged in a first direction perpendicular to a main surface of a substrate and extending in a second direction crossing the first direction; second lines arranged in the second direction, extending in the first direction, and intersecting the first lines; memory cells disposed at intersections of the first lines and the second lines; and an interlayer insulating film provided between the second lines. The interlayer insulating film has an air gap extending continuously in the first direction so as to intersect at least some of the first lines aligned along the first direction. The interlayer insulating film also includes an insulating film positioned above the air gap and having a curved surface that protrudes toward a direction of the substrate.Type: ApplicationFiled: April 28, 2014Publication date: June 25, 2015Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Atsushi YOSHIDA, Hiroshi Kanno, Takayuki Tsukamoto, Takamasa Okawa, Hideyuki Tabata
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Patent number: 9042158Abstract: A nonvolatile semiconductor memory device according to an embodiment includes a memory cell block that includes a memory cell array, the memory cell array including: a plurality of first lines; a plurality of second lines intersecting the plurality of first lines; and a memory cell that is provided at each of intersections of the plurality of first lines and the plurality of second lines and includes a variable resistance element, the memory cell array further including a protective resistance film that is provided respectively at each of the intersections of the plurality of first lines and the plurality of second lines and that is connected in series with the memory cell and ohmically contacts the memory cell, and the protective resistance film being configured from a material having a resistivity of 1˜100 ?·cm.Type: GrantFiled: September 11, 2013Date of Patent: May 26, 2015Assignee: KABUSHIKI KAISHA TOSHIBAInventors: Yoichi Minemura, Takayuki Tsukamoto, Takamasa Okawa, Hiroshi Kanno, Atsushi Yoshida, Satoshi Konagai, Nobuaki Yasutake
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Publication number: 20150117089Abstract: A semiconductor memory device according to an embodiment includes a memory cell array and a control circuit. The memory cell array includes first lines and second lines intersecting each other, a third line commonly connecting to the first lines, memory cells disposed at intersections of the first lines and the second lines, respectively. The control circuit is configured to execute a state determining operation detecting a voltage of the third line, and adjust a voltage applied to the first lines and the second lines during a resetting operation or a setting operation based on a result of the state determining operation. The resetting operation raises a resistance value of the variable resistance element. The setting operation lowers the resistance value of the variable resistance element.Type: ApplicationFiled: June 16, 2014Publication date: April 30, 2015Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yoichi MINEMURA, Takayuki TSUKAMOTO, Hiroshi KANNO, Takamasa OKAWA, Atsushi YOSHIDA, Hideyuki TABATA
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Publication number: 20150103582Abstract: This semiconductor memory device comprises a memory cell array that includes: a plurality of first lines; a plurality of second lines intersecting the plurality of first lines; a plurality of memory cells each disposed at an intersection of the plurality of first lines and the plurality of second lines and including a variable resistance element; and a select transistor respectively connected to an end of the plurality of first lines. The select transistor includes a gate electrode, a gate insulating film, and a conductive layer. Moreover, one end of that conductive layer is connected to the end of the first line, and a non-linear resistance layer configured from a non-linear material is connected between the first line and the conductive layer.Type: ApplicationFiled: February 12, 2014Publication date: April 16, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Takamasa OKAWA, Takayuki TSUKAMOTO, Yoichi MINEMURA, Hiroshi KANNO, Atsushi YOSHIDA, Hideyuki TABATA
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Publication number: 20150098261Abstract: A nonvolatile semiconductor memory device comprises: a memory cell array including first interconnections, second interconnections intersecting the first interconnections, and memory cells having a variable resistance element and being provided at respective intersections of the first interconnections and the second interconnections, the memory cell array being divided into bays including a predetermined number of the memory cells; and a control circuit configured to execute a first write step and a second write step executed after the first write step at a data writing operation, wherein the control circuit is configured to change over the number of simultaneously selected bits and/or the number of simultaneously selected bays depending upon whether a write step is the first write step or the second write step.Type: ApplicationFiled: January 16, 2014Publication date: April 9, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Hideyuki Tabata, Takayuki Tsukamoto
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Publication number: 20150098265Abstract: A nonvolatile semiconductor memory device according to an embodiment includes a control circuit configured to cause data to be stored in a memory cell by setting the memory cell to be included in one of resistance value distributions. The control circuit is configured to set a first resistance value distribution and a second resistance value distribution, the second resistance value distribution having a resistance value larger than that of the first resistance value distribution, and to set a second width to be larger than a first width, the second width being a width between a second upper limit value of the second resistance value distribution and a second lower limit value of the second resistance value distribution, and the first width being a width between a first upper limit value of the first resistance value distribution and a first lower limit value of the first resistance value distribution.Type: ApplicationFiled: March 13, 2014Publication date: April 9, 2015Applicant: Kabushiki Kaisha ToshibaInventors: Yoichi Minemura, Takayuki Tsukamoto, Takamasa Okawa, Hiroshi Kanno, Atsushi Yoshida
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Publication number: 20150092867Abstract: A device receives ASK signals by using an ASK signal receiving circuit that is different from an ASK signal receiving circuit for R/W mode, when an NFC-enabled semiconductor device operates in a mode other than the R/W mode. An ASK signal receiving circuit for 100% ASK is provided on the side of a pair of transmitting terminals. This arrangement eliminates the influence of an ESD provided within an ASK signal receiving circuit for 10% ASK coupled to a pair of receiving terminals. There is no need for management of threshold values that are different according to type of ASK and it is possible to support different modulation schemes by a smaller circuit configuration.Type: ApplicationFiled: December 9, 2014Publication date: April 2, 2015Inventor: Takayuki Tsukamoto
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Patent number: 8988925Abstract: A nonvolatile semiconductor memory device in accordance with an embodiment comprises a plurality of first, second lines, a plurality of memory cells, and a control circuit. The plurality of second lines extend so as to intersect the first lines. The plurality of memory cells are disposed at intersections of the first, second lines, and each includes a variable resistor. The control circuit is configured to control a voltage applied to the memory cells. The control circuit applies a first pulse voltage to the variable resistor during a forming operation. In addition, the control circuit applies a second pulse voltage to the variable resistor during a setting operation, the second pulse voltage having a polarity opposite to the first pulse voltage. Furthermore, the control circuit applies a third pulse voltage to the variable resistor during a resetting operation, the third pulse voltage having a polarity identical to the first pulse voltage.Type: GrantFiled: August 29, 2012Date of Patent: March 24, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Reika Ichihara, Takayuki Tsukamoto
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Patent number: 8971090Abstract: A semiconductor memory device according to an embodiment comprises: a memory cell array including memory cells, each of the memory cells disposed at each of intersections of first lines and second lines and including a variable resistor; and a control circuit configured to apply a first voltage to a selected first line and to apply a second voltage having a voltage value which is smaller than that of the first voltage to a selected second line, such that a selected memory cell is applied with a first potential difference required in an operation of the selected memory cell. The control circuit is configured such that when the first potential difference is applied a plurality of times to a plurality of the selected memory cells to execute the operation, the number of selected memory cells simultaneously applied with the first potential difference can be changed.Type: GrantFiled: February 22, 2013Date of Patent: March 3, 2015Assignee: Kabushiki Kaisha ToshibaInventors: Takayuki Tsukamoto, Jun Nishimura, Masahiro Une, Takafumi Shimotori, Yoichi Minemura, Hiroshi Kanno