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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Publication number: 20140063908Abstract: 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: ApplicationFiled: February 22, 2013Publication date: March 6, 2014Applicant: Kabushiki Kaisha ToshibaInventors: Takayuki Tsukamoto, Jun Nishimura, Masahiro Une, Takafumi Shimotori, Yoichi Minemura, Hiroshi Kanno
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Publication number: 20140063889Abstract: A nonvolatile semiconductor memory device according to an embodiment comprises: a memory cell array including first lines, second lines, and memory cells provided at each of intersections of the first lines and the second lines; and a control unit including a row control circuit, a first column control circuit provided on a side of one ends of the second lines, and a second column control circuit provided on a side of the other ends of the second lines, the control unit, during an access operation, controlling a potential of the first lines and the second lines such that a bias, which is lower than that applied to a certain unselected memory cell, is applied to those of unselected memory cells that are located more toward a center of the memory cell array in the column direction than the certain unselected memory cell.Type: ApplicationFiled: February 27, 2013Publication date: March 6, 2014Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yoichi MINEMURA, Takayuki TSUKAMOTO, Hiroshi KANNO, Takamasa OKAWA
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Patent number: 8665634Abstract: A memory cell array includes memory cells disposed at intersections of first lines and second lines, and each having a rectifying element and a variable resistance element connected in series. A control circuit, when performing an operation to change retained data, applies a first voltage to a selected first line and applies a second voltage to a selected second line; furthermore, applies a third voltage to a non-selected first line; and, moreover, applies a fourth voltage larger than the third voltage to a non-selected second line. An absolute value of a difference between the third voltage and the fourth voltage is set smaller than an absolute value of a difference between the first voltage and the second voltage by an amount of an offset voltage. A value of the offset voltage increases as the absolute value of the difference between the first and second voltages increases.Type: GrantFiled: August 31, 2012Date of Patent: March 4, 2014Assignee: Kabushiki Kaisha ToshibaInventors: Yoichi Minemura, Takayuki Tsukamoto, Hiroshi Kanno, Takamasa Okawa
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Patent number: 8605485Abstract: According to one embodiment, a control unit multiple-selects a first line for every N lines from a plurality of first lines. N is an integer greater than or equal to one. The control unit sets the multiple-selected first lines to a selection potential, and fixes potentials of non-selected first lines at least adjacent to the multiple-selected first lines at a first timing. The control unit causes the multiple-selected first lines to be in a floating state at a second timing after the first timing. The control unit selects one second line from the plurality of second lines and sets the one second line to a forming potential at a third timing after the second timing.Type: GrantFiled: January 13, 2012Date of Patent: December 10, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Hiroshi Kanno, Takafumi Shimotori, Yoichi Minemura, Takahiko Sasaki, Takayuki Tsukamoto
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Patent number: 8581424Abstract: According to one embodiment, an information recording/reproducing device including a semiconductor substrate, a first interconnect layer on the semiconductor substrate, a first memory cell array layer on the first interconnect layer, and a second interconnect layer on the first memory cell array layer. The first memory cell array layer comprises an insulating layer having an alignment mark, and a stacked layer structure on the insulating layer and including a storage layer and an electrode layer. All of the layers in the stacked layer structure comprises a material with a permeability of visible light of 1% or more.Type: GrantFiled: September 9, 2011Date of Patent: November 12, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Takahiro Hirai, Tsukasa Nakai, Kohichi Kubo, Chikayoshi Kamata, Takayuki Tsukamoto, Shinya Aoki
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Patent number: 8576606Abstract: A nonvolatile semiconductor memory device according to an embodiment herein includes a memory cell array. The memory cell array includes memory cells each provided between a first line and a second line and each including a variable resistor. A control circuit applies through the first and second lines a voltage necessary for a forming operation of the memory cell. A current limiting circuit limits a value of a current flowing across the memory cell during the forming operation to a certain limit value. The control circuit repeats an operation of applying the voltage by setting the limit value to a certain value and an operation of changing the limit value from the certain value, until forming of the memory cell is achieved.Type: GrantFiled: March 21, 2011Date of Patent: November 5, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Tetsuji Kunitake, Takashi Shigeoka, Takayuki Tsukamoto, Hironori Wakai, Hisashi Kato
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Publication number: 20130229852Abstract: According to one embodiment, a semiconductor memory device includes a semiconductor substrate, a plurality of memory cells, a plurality of wires, and a control circuit. The control circuit allows a first current to change a state to flow on a selected cell by applying a first potential difference between a pair of wires that sandwich the selected cell selected from the plurality of memory cells with respect to the semiconductor substrate vertically, and allows a second current lower than the first current to flow on an non-selected cell in the same direction as the direction of the first current by applying a second potential difference between a pair of wires that sandwich the non-selected cell connected to a wire shared with the selected cell on a different layer from the selected cell.Type: ApplicationFiled: August 30, 2012Publication date: September 5, 2013Applicant: Kabushiki Kaisha ToshibaInventors: Hiroshi KANNO, Yoichi Minemura, Mizuki Kaneko, Tomonori Kurosawa, Takafumi Shimotori, Takayuki Tsukamoto
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Publication number: 20130229854Abstract: A memory cell array includes memory cells disposed at intersections of first lines and second lines, and each having a rectifying element and a variable resistance element connected in series. A control circuit, when performing an operation to change retained data, applies a first voltage to a selected first line and applies a second voltage to a selected second line; furthermore, applies a third voltage to a non-selected first line; and, moreover, applies a fourth voltage larger than the third voltage to a non-selected second line. An absolute value of a difference between the third voltage and the fourth voltage is set smaller than an absolute value of a difference between the first voltage and the second voltage by an amount of an offset voltage. A value of the offset voltage increases as the absolute value of the difference between the first and second voltages increases.Type: ApplicationFiled: August 31, 2012Publication date: September 5, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yoichi MINEMURA, Takayuki TSUKAMOTO, Hiroshi KANNO, Takamasa OKAWA
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Publication number: 20130229850Abstract: 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: ApplicationFiled: August 29, 2012Publication date: September 5, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Mizuki Kaneko, Tomonori Kurosawa, Yoichi Minemura, Hiroshi Kanno, Takafumi Shimotori, Takayuki Tsukamoto
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Publication number: 20130229853Abstract: 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: ApplicationFiled: August 30, 2012Publication date: September 5, 2013Applicant: Kabushiki Kaisha ToshibaInventors: Yoichi MINEMURA, Takayuki Tsukamoto, Takafumi Shimotori, Hiroshi Kanno, Tomonori Kurosawa, Mizuki Kaneko
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Publication number: 20130229851Abstract: In a memory cell array, memory cells each including a variable resistance element are arranged at crossing portions between a plurality of first wiring and a plurality of second wirings. A control circuit executes a set operation, a reset operation, and a training operation. In the set operation, a set pulse is applied to the variable resistance element to change the variable resistance element from a high resistance state to a low resistance state. In the reset operation, a reset pulse having an opposite polarity to the polarity of the set pulse is applied to the variable resistance element to change the variable resistance element from the low resistance state to the high resistance state. In the training operation, the set pulse and the reset pulse are continuously applied to the variable resistance element.Type: ApplicationFiled: August 29, 2012Publication date: September 5, 2013Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Tomonori KUROSAWA, Mizuki Kaneko, Takafumi Shimotori, Takayuki Tsukamoto, Yoichi Minemura, Hiroshi Kanno
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Patent number: 8488367Abstract: According to one embodiment, a method for controlling a semiconductor device comprises determining a select bit number for a group of memory cells each includes a variable-resistance element, setting a first voltage corresponding to the select bit number, applying the set first voltage to the memory cell group, and performing verify read on the memory cell group to which the first voltage has been applied and determining whether or not the memory cell group passes the verify read. If the memory cell group is determined not to pass the verify read, the number of bits corresponding to passed memory cells is subtracted from the select bit number, and the first voltage corresponding to the decreased select bit number is set again.Type: GrantFiled: March 21, 2011Date of Patent: July 16, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Takafumi Shimotori, Yoichi Minemura, Hiroshi Kanno, Takayuki Tsukamoto, Jun Nishimura, Masahiro Une
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Patent number: 8487345Abstract: According to one embodiment, an information recording and reproducing device includes a stacked body. The stacked body includes a first layer, a second layer and a recording layer provided between the first layer and the second layer. The recording layer includes a phase-change material and a crystal nucleus. The phase-change material is capable of reversely changing between a crystal state and an amorphous state by a current supplied via the first layer and the second layer. The crystal nucleus is provided in contact with the phase-change material and includes a crystal nucleus material having a crystal structure identical to a crystal structure of the crystal state of the phase-change material, and a crystal nucleus coating provided on a surface of the crystal nucleus material and having a composition different from a composition of the crystal nucleus material.Type: GrantFiled: September 20, 2010Date of Patent: July 16, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Takayuki Tsukamoto, Tsukasa Nakai, Akira Kikitsu, Takeshi Yamaguchi, Sumio Ashida
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Patent number: 8431920Abstract: According to one embodiment, an information recording and reproducing device includes a recording layer which includes a typical element and a transition element, and stores a state of a first electric resistivity and a state of a second electric resistivity different from the first electric resistivity by a movement of the typical element, and an electrode layer which is disposed at one end of the recording layer to apply a voltage or a current to the recording layer. The recording layer includes a first region which is in contact with the electrode layer and the electrode layer includes a second region which is in contact with the recording layer. The first and second regions are opposite to each other. And the first and second regions include the typical element, and a concentration of the typical element in the second region is higher than that in the first region.Type: GrantFiled: September 17, 2010Date of Patent: April 30, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Chikayoshi Kamata, Takayuki Tsukamoto, Takeshi Yamaguchi, Tsukasa Nakai, Takahiro Hirai, Shinya Aoki, Kohichi Kubo
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Patent number: 8416606Abstract: According to one embodiment, an information recording and reproducing device includes a recording layer and a driving unit. The recording layer includes a first layer containing a first compound. The first compound includes a first positive ion element. The first positive ion element is made of a transition metal element and serves as a first positive ion. The second positive ion element serves as a second positive ion. The driving unit is configured to generate a phase change in the recording layer and to record information by at least one of application of a voltage and application of a current to the recording layer. The coordination number of the first positive ion element at a position of a second coordination of the second positive ion element is 80% or more and less than 100% of the coordination number when the first compound is assumed to be a perfect crystal.Type: GrantFiled: March 4, 2011Date of Patent: April 9, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Takayuki Tsukamoto, Tsukasa Nakai, Chikayoshi Kamata, Mariko Hayashi, Fumihiko Aiga, Takeshi Yamaguchi
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Patent number: 8410540Abstract: According to one embodiment, a non-volatile memory device includes a stacked structure including a memory portion and an electrode having a surface facing the memory portion; and a voltage application portion to apply a voltage to the memory portion to change resistance. The surface includes first and second regions. The first region contains a first nonmetallic element and at least one element of a metallic element, Si, Ga, and As. The second region contains a second nonmetallic element and the at least one element. The second region has a content ratio of the second nonmetallic element higher than that in the first region. A difference in electronegativity between the second nonmetallic element and the at least one element is greater than that between the first nonmetallic element and the at least one element. At least one of the first and second regions has an anisotropic shape.Type: GrantFiled: September 20, 2010Date of Patent: April 2, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Takeshi Araki, Takeshi Yamaguchi, Mariko Hayashi, Kohichi Kubo, Takayuki Tsukamoto
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Patent number: 8391048Abstract: A non-volatile semiconductor memory device according to an aspect of embodiments of the present invention includes a memory cell array including: multiple first wirings; multiple second wirings crossing the multiple first wirings; and multiple electrically rewritable memory cells respectively arranged at intersections of the first wirings and the second wirings, and each formed of a variable resistor which stores a resistance value as data in a non-volatile manner. The non-volatile semiconductor memory device according to an aspect of the embodiments of the present invention further includes a controller for selecting a given one of the memory cells, generating an erase pulse which is used for erasing data, and supplying the erase pulse to the selected memory cell. The erase pulse has a pulse width which is increased or decreased exponentially in accordance with an access path length to the selected memory cell.Type: GrantFiled: July 29, 2010Date of Patent: March 5, 2013Assignee: Kabushiki Kaisha ToshibaInventors: Reika Ichihara, Takayuki Tsukamoto, Kenichi Murooka, Hirofumi Inoue, Hiroshi Kanno
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Patent number: 8374571Abstract: An integrated circuit is equipped with a reception mixer and a signal generator. A multistage delay circuit generates a plurality of clock pulses in response to a reception carrier signal. A phase detection unit detects differences between a voltage level of a specific clock pulse and voltage levels of a predetermined number of clock pulses generated prior to the specific clock pulse to thereby detect a predetermined phase of the specific clock pulse. A selector of a clock generation unit outputs a plurality of selection clock pulse signals respectively having a plurality of phases from the clock pulse signals. A first signal synthetic logic circuit performs logical operations on the selection clock pulses to thereby generate local signals supplied to the reception mixer.Type: GrantFiled: October 24, 2011Date of Patent: February 12, 2013Assignee: Renesas Electronics CorporationInventors: Atsushi Motozawa, Takayuki Tsukamoto, Tatsuji Matsuura, Yuichi Okuda
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Publication number: 20120320662Abstract: 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: ApplicationFiled: August 29, 2012Publication date: December 20, 2012Applicant: Kabushiki Kaisha ToshibaInventors: Reika ICHIHARA, Takayuki Tsukamoto
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Patent number: 8324606Abstract: A resistance change type memory of an aspect of the present invention including a first wiring configured to extend in a first direction, a second wiring configured to extend in a second direction crossing the first direction, a series circuit configured to connect to the first and second wirings, the series circuit including a non-ohmic element being more conductive in the first to second wiring direction than in the second to first direction and a resistance change type storage element in which data is stored according to a change of a resistance state, an energy supplying circuit configured to connect to the first wiring to supply energy to the first wiring, the energy being used to store the data in the resistance change type storage element, and a capacitance circuit configured to include a capacitive element and being connected to the second wiring.Type: GrantFiled: September 21, 2009Date of Patent: December 4, 2012Assignee: Kabushiki Kaisha ToshibaInventors: Takayuki Tsukamoto, Reika Ichihara, Hiroshi Kanno, Kenichi Murooka