Patents by Inventor Tadahiko Sugibayashi
Tadahiko Sugibayashi 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: 10312288Abstract: In the cases of performing programming by forming a two-terminal-type variable resistance element on a semiconductor device, it has been difficult to control the programming, and malfunctions have often occurred. This switching element includes at least a first variable resistance element, a second variable resistance element, a first rectifying element, and a second rectifying element, one end of the first variable resistance element and one end of the second variable resistance element are respectively connected to one end of the first rectifying element and one end of the second rectifying element, and each of the rectifying elements has two terminals.Type: GrantFiled: April 6, 2016Date of Patent: June 4, 2019Assignee: NEC CORPORATIONInventors: Munehiro Tada, Tadahiko Sugibayashi
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Patent number: 10262738Abstract: In order to provide a technique for reducing an area of a content addressable memory cell and suppressing a leak current in a content addressable memory which calculates similarity, a content addressable memory cell of the present invention, comprising: a resistance network which includes plural current paths, a logic circuit for selecting a current path in response to input data, and a variable-resistance-type non-volatile memory element that is arranged on at least one current path and stores data and whose resistance value is changed according to a result of logical calculation based on the input data and the stored data; and a charge/discharge circuit which is connected with the resistance network and a match line and whose delay time from inputting a signal through the match line until outputting the signal is changed according to the result of logical calculation based on the input data and the stored data.Type: GrantFiled: June 17, 2014Date of Patent: April 16, 2019Assignee: NEC CORPORATIONInventors: Ryusuke Nebashi, Noboru Sakimura, Tadahiko Sugibayashi
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Patent number: 10074421Abstract: In order to provide a crossbar switch type memory circuit designed to be usable in normal circumstances even when a resistance change element is in an adverse state, the present invention is provided with: a first unit including a first column wiring to which one end of a first resistance change element is connected, a first power supply-side transistor for controlling the connection of the first column wiring and a power supply node, a first ground-side transistor, of a reverse operation type to the first power supply-side transistor, for controlling the connection of the first column wiring and a ground node, and a first polarity control line for causing the first power supply-side transistor or the first ground-side transistor to turn on and the other to turn off by a polar signal from a polar signal terminal, the first polarity control line being connected to the control terminals of the first power supply-side transistor and first ground-side transistor; a second unit including a second column wiring toType: GrantFiled: March 1, 2016Date of Patent: September 11, 2018Assignee: NEC CORPORATIONInventors: Makoto Miyamura, Noboru Sakimura, Yukihide Tsuji, Ryusuke Nebashi, Tadahiko Sugibayashi
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Publication number: 20180096724Abstract: In order to provide a crossbar switch type memory circuit designed to be usable in normal circumstances even when a resistance change element is in an adverse state, the present invention is provided with: a first unit including a first column wiring to which one end of a first resistance change element is connected, a first power supply-side transistor for controlling the connection of the first column wiring and a power supply node, a first ground-side transistor, of a reverse operation type to the first power supply-side transistor, for controlling the connection of the first column wiring and a ground node, and a first polarity control line for causing the first power supply-side transistor or the first ground-side transistor to turn on and the other to turn off by a polar signal from a polar signal terminal, the first polarity control line being connected to the control terminals of the first power supply-side transistor and first ground-side transistor; a second unit including a second column wiring toType: ApplicationFiled: March 1, 2016Publication date: April 5, 2018Applicant: NEC CorporationInventors: Makoto MIYAMURA, Noboru SAKIMURA, Yukihide TSUJI, Ryusuke NEBASHI, Tadahiko SUGIBAYASHI
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Publication number: 20180061890Abstract: In the cases of performing programming by forming a two-terminal-type variable resistance element on a semiconductor device, it has been difficult to control the programming, and malfunctions have often occurred. This switching element includes at least a first variable resistance element, a second variable resistance element, a first rectifying element, and a second rectifying element, one end of the first variable resistance element and one end of the second variable resistance element are respectively connected to one end of the first rectifying element and one end of the second rectifying element, and each of the rectifying elements has two terminals.Type: ApplicationFiled: April 6, 2016Publication date: March 1, 2018Applicant: NEC CorporationInventors: Munehiro TADA, Tadahiko SUGIBAYASHI
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Patent number: 9837816Abstract: A semiconductor device includes a current control unit whose conductance is variable and a control unit configured to control the conductance of the current control unit. The current control unit is connected to a direct current power source in parallel with a load for the direct current power source, through a capacitor. The control unit sets the current control unit to a first conductance when the direct current power source and the load are not in a conduction state, and sets the current control unit to a second conductance larger than the first conductance when the direct current power source and the load are in the conduction state.Type: GrantFiled: March 28, 2013Date of Patent: December 5, 2017Assignee: NEC CORPORATIONInventors: Makoto Miyamura, Noboru Sakimura, Ryusuke Nebashi, Yukihide Tsuji, Tadahiko Sugibayashi
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Patent number: 9799822Abstract: A disclosed magnetic memory element includes: a magnetization free layer formed of a ferromagnetic substance having perpendicular magnetic anisotropy; a response layer provided so as to be opposed to the magnetization free layer and formed of a ferromagnetic substance having perpendicular magnetic anisotropy; a non-magnetic layer provided so as to be opposed to the response layer on a side opposite to the magnetization free layer and formed of a non-magnetic substance; and a reference layer provided so as to be opposed to the non-magnetic layer on a side opposite to the response layer and formed of a ferromagnetic substance having perpendicular magnetic anisotropy. The magnetization free layer includes a first magnetization fixed region and a second magnetization fixed region which have magnetization fixed in directions antiparallel to each other, and a magnetization free region in which a magnetization direction is variable.Type: GrantFiled: April 19, 2012Date of Patent: October 24, 2017Assignees: NEC CORPORATION, TOHOKU UNIVERSITYInventors: Shunsuke Fukami, Nobuyuki Ishiwata, Tadahiko Sugibayashi, Hideo Ohno, Shoji Ikeda, Michihiko Yamanouchi
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Patent number: 9536584Abstract: A nonvolatile logic gate device is configured to include a resistive network of a memory structure in which at least three nonvolatile resistive elements are connected, a reference resistive network as a reference resistance providing a tolerance of the memory structure to a resistance value of the resistive network of the memory structure, a writing part operable to selectively write or rewrite a value of each of the nonvolatile resistive elements in the resistive network into a maximum or a minimum corresponding to a logical value to be read when data are stored into the resistive network, and a logic circuit structure operable to use, as a logical value of the memory structure, a value obtained by comparison between the resistance value of the resistive network and the resistance value of the reference resistive network.Type: GrantFiled: May 15, 2013Date of Patent: January 3, 2017Assignees: NEC CORPORATION, TOHOKU UNIVERSITYInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Ayuka Tada, Tadahiko Sugibayashi, Takahiro Hanyu, Tetsuo Endoh, Hideo Ohno
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Patent number: 9478309Abstract: Provided is a magnetic domain wall displacement memory cell, including a recording layer including a magnetic film, the recording layer including: a magnetization reversal region in which magnetization is reversible; and first and second magnetization fixed regions that supply a spin-polarized electron to the magnetization reversal region. The magnetic domain wall displacement memory cell is configured so that a first region in which magnetization reversal occurs due to a first current flowing in a direction parallel to a film surface of the recording layer and a first magnetic field component in the direction parallel to the film surface of the recording layer is formed, and a second region in which no magnetization reversal occurs is formed.Type: GrantFiled: September 13, 2013Date of Patent: October 25, 2016Assignees: NEC CORPORATION, TOHOKU UNIVERSITYInventors: Ryusuke Nebashi, Noboru Sakimura, Tadahiko Sugibayashi, Yukihide Tsuji, Ayuka Tada, Hiroaki Honjou, Hideo Ohno
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Patent number: 9379312Abstract: A magnetoresistive effect element of the present invention includes: a domain wall motion layer, a spacer layer and a reference layer. The domain wall motion layer is made of ferromagnetic material with perpendicular magnetic anisotropy. The spacer layer is formed on the domain wall motion layer and made of non-magnetic material. The reference layer is formed on the spacer layer and made of ferromagnetic material, magnetization of the reference layer being fixed. The domain wall motion layer includes at least one domain wall, and stores data corresponding to a position of the domain wall. An anisotropy magnetic field of the domain wall motion layer is larger than a value in which the domain wall motion layer can hold the perpendicular magnetic anisotropy, and smaller than an essential value of an anisotropy magnetic field of the ferromagnetic material of the domain wall motion layer.Type: GrantFiled: December 14, 2010Date of Patent: June 28, 2016Assignee: NEC CORPORATIONInventors: Tadahiko Sugibayashi, Eiji Kariyada, Kaoru Mori, Norikazu Ohshima, Shunsuke Fukami, Tetsuhiro Suzuki, Hironobu Tanigawa, Sadahiko Miura, Nobuyuki Ishiwata
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Patent number: 9299435Abstract: Provided is a nonvolatile content addressable memory. Each word circuit includes a plurality of segments having an order relation. Each of the segments includes one or more memory cells. Each of the memory cells includes a nonvolatile storage element. Each of the segments includes a power switch for turning on/off a power of a memory cell of the segment. During stand-by, all the power switches are turned off, and, in search operation, the power switch is turned on as necessary for each of the segments.Type: GrantFiled: August 1, 2013Date of Patent: March 29, 2016Assignees: NEC CORPORATION, TOHOKU UNIVERSITYInventors: Noboru Sakimura, Ryusuke Nebashi, Tadahiko Sugibayashi, Shoun Matsunaga, Takahiro Hanyu, Hideo Ohno
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Publication number: 20150248939Abstract: Provided is a magnetic domain wall displacement memory cell, including a recording layer including a magnetic film, the recording layer including: a magnetization reversal region in which magnetization is reversible; and first and second magnetization fixed regions that supply a spin-polarized electron to the magnetization reversal region. The magnetic domain wall displacement memory cell is configured so that a first region in which magnetization reversal occurs due to a first current flowing in a direction parallel to a film surface of the recording layer and a first magnetic field component in the direction parallel to the film surface of the recording layer is formed, and a second region in which no magnetization reversal occurs is formed.Type: ApplicationFiled: September 13, 2013Publication date: September 3, 2015Applicants: NEC Corporation, Tohoku UniversityInventors: Ryusuke Nebashi, Noboru Sakimura, Tadahiko Sugibayashi, Yukihide Tsuji, Ayuka Tada, Hiroaki Honjou, Hideo Ohno
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Publication number: 20150235703Abstract: Provided is a nonvolatile content addressable memory. Each word circuit includes a plurality of segments having an order relation. Each of the segments includes one or more memory cells. Each of the memory cells includes a nonvolatile storage element. Each of the segments includes a power switch for turning on/off a power of a memory cell of the segment. During stand-by, all the power switches are turned off, and, in search operation, the power switch is turned on as necessary for each of the segments.Type: ApplicationFiled: August 1, 2013Publication date: August 20, 2015Applicants: TOHOKU UNIVERSITY, NEC CORPORATIONInventors: Noboru Sakimura, Ryusuke Nebashi, Tadahiko Sugibayashi, Shoun Matsunaga, Takahiro Hanyu, Hideo Ohno
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Patent number: 9100013Abstract: Provided is a nonvolatile resistor network assembly characterized by that: it comprises a first and a second resistor network which are each composed of a plurality of nonvolatile resistive elements connected together; it also comprises a write means for writing into the first and second resistor networks; and writing into the first and second resistor networks is performed by the use of the write means in a manner to make total resistances of respectively the first and second resistor networks different from each other. Further provided is a nonvolatile logic gate which performs logical operation using stored data determined by the total resistances of the respective nonvolatile resistor networks.Type: GrantFiled: September 6, 2012Date of Patent: August 4, 2015Assignee: NEC CORPORATIONInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Tadahiko Sugibayashi
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Publication number: 20150138877Abstract: A nonvolatile logic gate device is configured to include a resistive network of a memory structure in which at least three nonvolatile resistive elements are connected, a reference resistive network as a reference resistance providing a tolerance of the memory structure to a resistance value of the resistive network of the memory structure, a writing part operable to selectively write or rewrite a value of each of the nonvolatile resistive elements in the resistive network into a maximum or a minimum corresponding to a logical value to be read when data are stored into the resistive network, and a logic circuit structure operable to use, as a logical value of the memory structure, a value obtained by comparison between the resistance value of the resistive network and the resistance value of the reference resistive network.Type: ApplicationFiled: May 15, 2013Publication date: May 21, 2015Applicants: TOHOKU UNIVERSITY, NEC CORPORATIONInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Ayuka Tada, Tadahiko Sugibayashi, Takahiro Hanyu, Tetsuo Endoh, Hideo Ohno
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Publication number: 20150048680Abstract: A semiconductor device includes a current control unit whose conductance is variable and a control unit configured to control the conductance of the current control unit. The current control unit is connected to a direct current power source in parallel with a load for the direct current power source, through a capacitor. The control unit sets the current control unit to a first conductance when the direct current power source and the load are not in a conduction state, and sets the current control unit to a second conductance larger than the first conductance when the direct current power source and the load are in the conduction state.Type: ApplicationFiled: March 28, 2013Publication date: February 19, 2015Inventors: Makoto Miyamura, Noboru Sakimura, Ryusuke Nebashi, Yukihide Tsuji, Tadahiko Sugibayashi
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Publication number: 20150042376Abstract: Provided is a nonvolatile resistor network assembly characterized by that: it comprises a first and a second resistor network which are each composed of a plurality of nonvolatile resistive elements connected together; it also comprises a write means for writing into the first and second resistor networks; and writing into the first and second resistor networks is performed by the use of the write means in a manner to make total resistances of respectively the first and second resistor networks different from each other. Further provided is a nonvolatile logic gate which performs logical operation using stored data determined by the total resistances of the respective nonvolatile resistor networks.Type: ApplicationFiled: September 6, 2012Publication date: February 12, 2015Applicant: NEC CORPORATIONInventors: Ryusuke Nebashi, Noboru Sakimura, Yukihide Tsuji, Tadahiko Sugibayashi
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Patent number: 8902644Abstract: A magnetoresistive element 10 having a memory cell 100 according to the present invention contains a first lower terminal n1 and a second lower terminal n2 respectively connected to both ends of a conductive layer 3 whose longitudinal direction is different from the column direction (X direction). Further, the gates of the first transistors M1 respectively included in two memory cells among the plurality of memory cells 100 and adjacent to each other in a row direction (Y direction) are commonly connected to a first word line 14. As a result, without increase of the cell area, it becomes possible to reserve a margin in the dimension of the cell structure or in the process for MRMA.Type: GrantFiled: December 6, 2011Date of Patent: December 2, 2014Assignee: NEC CorporationInventors: Noboru Sakimura, Ryusuke Nebashi, Tadahiko Sugibayashi
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Patent number: 8737119Abstract: A magnetic memory cell 1 is provided with a magnetic recording layer 10 which is a ferromagnetic layer and a pinned layer 30 connected with the magnetic recording layer 10 through a non-magnetic layer 20. The magnetic recording layer 10 has a magnetization inversion region 13, a first magnetization fixed region 11 and a second magnetization fixed region 12. The magnetization inversion region 13 has a magnetization whose orientation is invertible and overlaps the pinned layer 30. The first magnetization fixed region 11 is connected with a first boundary B1 in the magnetization inversion region 13 and a magnetization orientation is fixed on a first direction. The second magnetization fixed region 12 is connected with a second boundary B2 in magnetization inversion region 13 and a magnetization orientation is fixed on a second direction. The first direction and the second direction are opposite to each other.Type: GrantFiled: March 29, 2012Date of Patent: May 27, 2014Assignee: NEC CorporationInventors: Takeshi Honda, Noboru Sakimura, Tadahiko Sugibayashi, Hideaki Numata, Norikazu Ohshima
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Publication number: 20140097509Abstract: A disclosed magnetic memory element includes: a magnetization free layer formed of a ferromagnetic substance having perpendicular magnetic anisotropy; a response layer provided so as to be opposed to the magnetization free layer and formed of a ferromagnetic substance having perpendicular magnetic anisotropy; a non-magnetic layer provided so as to be opposed to the response layer on a side opposite to the magnetization free layer and formed of a non-magnetic substance; and a reference layer provided so as to be opposed to the non-magnetic layer on a side opposite to the response layer and formed of a ferromagnetic substance having perpendicular magnetic anisotropy. The magnetization free layer includes a first magnetization fixed region and a second magnetization fixed region which have magnetization fixed in directions antiparallel to each other, and a magnetization free region in which a magnetization direction is variable.Type: ApplicationFiled: April 19, 2012Publication date: April 10, 2014Applicant: TOHOKU UNIVERSITYInventors: Shunsuke Fukami, Nobuyuki Ishiwata, Tadahiko Sugibayashi, Hideo Ohno, Shoji Ikeda, Michihiko Yamanouchi