Patents by Inventor Hiroyuki Akinaga
Hiroyuki Akinaga 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: 20240127982Abstract: An information processing apparatus includes a converting portion having a plurality of electrical conductors to be arranged in mutual separation and a medium arranged so as to mutually connect the plurality of electrical conductors, wherein the converting portion is the information processing apparatus to convert an input signal to an output signal. The medium includes the electrolyte and is configured to be capable of controlling an electrical conductivity of an electrically conductive path mutually electrically connecting the plurality of electrical conductors, and the medium is selected such that the electrical conductivity of the electrically conductive path changes over time with the input signal not being present.Type: ApplicationFiled: January 27, 2022Publication date: April 18, 2024Applicants: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, TOKYO UNIVERSITY OF SCIENCE FOUNDATION, TOYOTA PHYSICAL AND CHEMICAL RESEARCH INSTITUTE, NATIONAL UNIVERSITY CORPORATION TOTTORI UNIVERSITY, NAGASE & CO., LTD.Inventors: Hiroyuki AKINAGA, Hisashi SHIMA, Yasuhisa NAITOH, Hiroshi SATOU, Dan SATOU, Takuma MATSUO, Kentaro KINOSHITA, Toshiyuki ITOH, Toshiki NOKAMI, Masakazu KOBAYASHI
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Patent number: 11933752Abstract: A gas sensor includes: a gas-sensitive body layer disposed above a substrate and including a metal oxide layer; a first electrode on the gas-sensitive body layer; and a second electrode on the gas-sensitive body layer, being apart from the first electrode by a gap. The gas-sensitive body layer has a resistance change characteristic that reversibly transitions to a high-resistance state and a low-resistance state on basis of a voltage applied across the first electrode and the second electrode. At least a part of the gas-sensitive body layer is exposed to the gap. The gas-sensitive body layer has a resistance that decreases when gas containing a hydrogen atom is in contact with the second electrode.Type: GrantFiled: July 23, 2019Date of Patent: March 19, 2024Assignee: NUVOTON TECHNOLOGY CORPORATION JAPANInventors: Satoru Fujii, Zhiqiang Wei, Kazunari Homma, Shinichi Yoneda, Yasuhisa Naito, Hisashi Shima, Hiroyuki Akinaga
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Patent number: 11889776Abstract: A variable resistance non-volatile memory element includes first and second electrodes and a variable resistance layer between the electrodes. The layer has a resistance value reversibly variable based on an electrical signal. The layer includes a first variable resistance layer that includes an oxygen deficient first metal oxide containing a first metal element and oxygen, and a second variable resistance layer that includes a composite oxide containing the first metal element, a second metal element different from the first metal element, and oxygen, and having a different degree of oxygen deficiency from the first metal oxide. The composite oxide has a lower degree of oxygen deficiency than the first metal oxide. At room temperature, the composite oxide has a smaller oxygen diffusion coefficient than a second metal oxide containing the first metal element and oxygen, and having the degree of oxygen deficiency equal to that of the composite oxide.Type: GrantFiled: June 23, 2021Date of Patent: January 30, 2024Assignee: Nuvoton Technology Corporation JapanInventors: Ryutaro Yasuhara, Satoru Fujii, Takumi Mikawa, Atsushi Himeno, Kengo Nishio, Takehide Miyazaki, Hiroyuki Akinaga, Yasuhisa Naitoh, Hisashi Shima
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Publication number: 20220407003Abstract: An information processing device, including a resistive analog neuromorphic device element having a pair of electrodes and an oxide layer provided between the pair of electrodes, and a parallel circuit having a low resistance component and a capacitance component. The parallel circuit and the resistive analog neuromorphic device element are connected in series.Type: ApplicationFiled: August 26, 2022Publication date: December 22, 2022Applicant: NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGYInventors: Hisashi SHIMA, Yasuhisa NAITOH, Hiroyuki AKINAGA, Makoto TAKAHASHI
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Publication number: 20220254998Abstract: A conductive bridge memory device includes a memory cell including a first metal layer; a second metal layer; a first insulator layer having a first surface facing the first metal layer and a second surface facing the second metal layer and being a surface opposite to the first surface, and having a through hole penetrating between the first surface and the second surface; and a liquid layer being formed of liquid containing a liquid electrolyte impregnated in the through hole.Type: ApplicationFiled: August 28, 2020Publication date: August 11, 2022Applicants: NATIONAL UNIVERSITY CORPORATION TOTTORI UNIVERSITY, NATIONAL INSTITUTE OF ADVANCED INDUSTRIAL SCIENCE AND TECHNOLOGY, NAGASE & CO., LTD.Inventors: Toshiyuki ITOH, Toshiki NOKAMI, Kentaro KINOSHITA, Hisashi SHIMA, Yasuhisa NAITOH, Hiroyuki AKINAGA, Hiroshi SATOU, Shigeki MORII, Kusuo OTA, Atsushi TANAKA
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Publication number: 20210320248Abstract: A variable resistance non-volatile memory element includes first and second electrodes and a variable resistance layer between the electrodes. The layer has a resistance value reversibly variable based on an electrical signal. The layer includes a first variable resistance layer that includes an oxygen deficient first metal oxide containing a first metal element and oxygen, and a second variable resistance layer that includes a composite oxide containing the first metal element, a second metal element different from the first metal element, and oxygen, and having a different degree of oxygen deficiency from the first metal oxide. The composite oxide has a lower degree of oxygen deficiency than the first metal oxide. At room temperature, the composite oxide has a smaller oxygen diffusion coefficient than a second metal oxide containing the first metal element and oxygen, and having the degree of oxygen deficiency equal to that of the composite oxide.Type: ApplicationFiled: June 23, 2021Publication date: October 14, 2021Inventors: Ryutaro YASUHARA, Satoru FUJII, Takumi MIKAWA, Atsushi HIMENO, Kengo NISHIO, Takehide MIYAZAKI, Hiroyuki AKINAGA, Yasuhisa NAITOH, Hisashi SHIMA
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Publication number: 20190346391Abstract: A gas sensor includes: a gas-sensitive body layer disposed above a substrate and including a metal oxide layer; a first electrode on the gas-sensitive body layer; and a second electrode on the gas-sensitive body layer, being apart from the first electrode by a gap. The gas-sensitive body layer has a resistance change characteristic that reversibly transitions to a high-resistance state and a low-resistance state on basis of a voltage applied across the first electrode and the second electrode. At least a part of the gas-sensitive body layer is exposed to the gap. The gas-sensitive body layer has a resistance that decreases when gas containing a hydrogen atom is in contact with the second electrode.Type: ApplicationFiled: July 23, 2019Publication date: November 14, 2019Inventors: Satoru Fujii, Zhiqiang Wei, Kazunari Homma, Shinichi Yoneda, Yasuhisa Naito, Hisashi Shima, Hiroyuki Akinaga
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Patent number: 8487415Abstract: The present invention provides a rectifier element that has a titanium oxide layer interposed between first and second electrodes containing a transition metal with an electronegativity larger than that of Ti, wherein, in the titanium oxide layer, only the interface on the side facing any one of the electrodes has a stoichiometric composition, and wherein the average composition of the whole layer is represented by the formula TiOx (wherein x satisfies the relationship 1.6?x<2), and wherein the rectifying characteristics can be reversed by applying a reverse electrical signal that exceeds the critical reverse electric power between the first and second electrodes in an opposite direction. The present invention also provides a process for producing a rectifier element, which includes the steps of depositing a first electrode that contains a transition metal with an electronegativity larger than that of Ti on a substrate; depositing a layer of titanium oxide (TiOx, wherein x satisfies the relationship 1.Type: GrantFiled: October 30, 2008Date of Patent: July 16, 2013Assignee: National Institute of Advanced Industrial Science and TechnologyInventors: Hisashi Shima, Hiroyuki Akinaga, Shoji Ishibashi, Tomoyuki Tamura
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Patent number: 8054674Abstract: Provided is a variable resistive element which performs high speed and low power consumption operation. The variable resistive element comprises a metal oxide layer between first and second electrodes wherein electrical resistance between the first and second electrodes reversibly changes in accordance with application of electrical stress across the first and second electrodes. The metal oxide layer has a filament, which is a current path where the density of a current flowing between the first and second electrodes locally increases. A portion including at least the vicinity of an interface between the certain electrode, which is one or both of the first and second electrodes, and the filament, on an interface between the certain electrode and the metal oxide layer is provided with an interface oxide which is an oxide of at least one element included in the certain electrode and different from the oxide of the metal oxide layer.Type: GrantFiled: April 7, 2008Date of Patent: November 8, 2011Assignees: Sharp Kabushiki Kaisha, National Institute of Advanced Industrial Science and TechnologyInventors: Yukio Tamai, Yasunari Hosoi, Nobuyoshi Awaya, Shigeo Ohnishi, Kazuya Ishihara, Hisashi Shima, Hiroyuki Akinaga, Fumiyoshi Takano
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Patent number: 7964924Abstract: A magneto-resistance effect device (1) includes a semiconductor region (2) having a surface provided with a plurality of isolated metal micro-particles (3) of not more than 100 ?m disposed at intervals of not more than 1 ?m, a semiconductor or half-metal cap layer (4) for covering the semiconductor region and a plurality of electrodes (5) disposed on a surface of the cap layer and separated from each other. The device exhibits a high magneto-resistance effect at room temperature, is highly sensible to a magnetic field and can be produced through a simple manufacturing process. The device is formed of a magneto-resistant material easy to match a semiconductor fabrication process. A magnetic field sensor using the device (1) has various excellent characteristics.Type: GrantFiled: May 24, 2002Date of Patent: June 21, 2011Assignee: National Institute of Advanced Industrial Science and TechnologyInventors: Hiroyuki Akinaga, Masaharu Oshima, Masaki Mizuguchi
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Patent number: 7923711Abstract: The present invention provides switching elements having a readout margin suitable for data storage units of nonvolatile memories, which are obtained by improving the resistance ratio of metal oxide thin films having reversible variable resistance properties. The present invention provides switching elements having a metal oxide consisting of a transition metal and oxygen formed between a first electrode and a second electrode, by modifying one or more of the crystal structure, ionic valence number of metal element, and nonstoichiometricity of a stoichiometric compound consisted of the transition metal and oxygen. The present invention also provides methods for producing switching elements having reversible variable resistance characteristics due to electric power application history.Type: GrantFiled: July 26, 2007Date of Patent: April 12, 2011Assignees: National Institute of Advanced Industrial Science and Technology, Sharp CorporationInventors: Hisashi Shima, Hiroyuki Akinaga, Fumiyoshi Takano, Yukio Tamai
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Patent number: 7894239Abstract: The variable resistance element of the present invention is a variable resistance element having an electrode, the other electrode, and a metal oxide material sandwiched between the electrodes and having an electrical resistance, between the electrodes, changing reversibly in response to a voltage applied between the electrodes. The variable resistance element further includes, inside the metal oxide material, a low resistance material having a lower electrical resistance than the metal oxide material and being out of contact with at least either one of the electrodes. This makes it possible to reduce a forming voltage for providing a conductive section inside the metal oxide material, without causing a leakage current to increase.Type: GrantFiled: December 4, 2008Date of Patent: February 22, 2011Assignees: Sharp Kabushiki Kaisha, National Institute of Advanced Industrial Science and TechnologyInventors: Yukio Tamai, Yasunari Hosoi, Nobuyoshi Awaya, Shigeo Ohnishi, Kazuya Ishihara, Hisashi Shima, Fumiyoshi Takano, Hiroyuki Akinaga
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Patent number: 7863594Abstract: An objective of the present invention is to provide a switching device that shows two markedly different stable resistance characteristics reversibly and repetitively, and which is applicable to highly integrated nonvolatile memories.Type: GrantFiled: August 8, 2006Date of Patent: January 4, 2011Assignee: National Institute of Advanced Industrial Science and TechnologyInventors: Hiroyuki Akinaga, Shuichiro Yasuda, Isao Inoue, Hidenori Takagi
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Publication number: 20100276684Abstract: The present invention provides a rectifier element that has a titanium oxide layer interposed between first and second electrodes containing a transition metal with an electronegativity larger than that of Ti, wherein, in the titanium oxide layer, only the interface on the side facing any one of the electrodes has a stoichiometric composition, and wherein the average composition of the whole layer is represented by the formula TiOx (wherein x satisfies the relationship 1.6?x<2), and wherein the rectifying characteristics can be reversed by applying a reverse electrical signal that exceeds the critical reverse electric power between the first and second electrodes in an opposite direction. The present invention also provides a process for producing a rectifier element, which includes the steps of depositing a first electrode that contains a transition metal with an electronegativity larger than that of Ti on a substrate; depositing a layer of titanium oxide (TiOx, wherein x satisfies the relationship 1.Type: ApplicationFiled: October 30, 2008Publication date: November 4, 2010Inventors: Hisashi Shima, Hiroyuki Akinaga, Shoji Ishibashi, Tomoyuki Tamura
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Publication number: 20100172170Abstract: Provided is a variable resistive element which performs high speed and low power consumption operation. The variable resistive element comprises a metal oxide layer between first and second electrodes wherein electrical resistance between the first and second electrodes reversibly changes in accordance with application of electrical stress across the first and second electrodes. The metal oxide layer has a filament, which is a current path where the density of a current flowing between the first and second electrodes locally increases. A portion including at least the vicinity of an interface between the certain electrode, which is one or both of the first and second electrodes, and the filament, on an interface between the certain electrode and the metal oxide layer is provided with an interface oxide which is an oxide of at least one element included in the certain electrode and different from the oxide of the metal oxide layer.Type: ApplicationFiled: April 7, 2008Publication date: July 8, 2010Inventors: Yukio Tamai, Yasunari Hosoi, Nobuyoshi Awaya, Shigeo Ohnishi, Kazuya Ishihara, Hisashi Shima, Hiroyuki Akinaga, Fumiyoshi Takano
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Publication number: 20100012911Abstract: An objective of the present invention is to provide a switching device that shows two markedly different stable resistance characteristics reversibly and repetitively, and which is applicable to highly integrated nonvolatile memories.Type: ApplicationFiled: August 8, 2006Publication date: January 21, 2010Applicant: National Institute of Advanced Industrial Science and TechnologyInventors: Hiroyuki Akinaga, Shuichiro Yasuda, Isao Inoue, Hidenori Takagi
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Publication number: 20090147558Abstract: The variable resistance element of the present invention is a variable resistance element having an electrode, the other electrode, and a metal oxide material sandwiched between the electrodes and having an electrical resistance, between the electrodes, changing reversibly in response to a voltage applied between the electrodes. The variable resistance element further includes, inside the metal oxide material, a low resistance material having a lower electrical resistance than the metal oxide material and being out of contact with at least either one of the electrodes. This makes it possible to reduce a forming voltage for providing a conductive section inside the metal oxide material, without causing a leakage current to increase.Type: ApplicationFiled: December 4, 2008Publication date: June 11, 2009Inventors: Yukio Tamai, Yasunari Hosoi, Nobuyoshi Awaya, Shigeo Ohnishi, Kazuya Ishihara, Hisashi Shima, Fumiyoshi Takano, Hiroyuki Akinaga
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Patent number: 7495215Abstract: The present invention provides a probe for a scanning magnetic force microscope having a resolution sufficient to allow observation of a magnetic storage medium with 1200 kFCI or higher recording densities, a method for producing the probe, and a method for forming a ferromagnetic alloy film on a carbon nanotube. In the context of the present invention, the probe for a scanning magnetic force microscope comprises a carbon nanotube whose surface is at least in part coated with a ferromagnetic alloy film consisting of any one of a Co—Fe alloy and a Co—Ni alloy, wherein the arithmetic mean roughness (Ra 10 ?m) of the surface of the ferromagnetic alloy film is controlled to 1.15 nm or less. A method for producing such probes for a scanning magnetic force microscope and a method for forming such a ferromagnetic alloy film on a carbon nanotube, so as to achieve such mean surface roughness by controlling the growth rate of the ferromagnetic alloy film within the range of 1.0 to 2.5 nm/min, is also disclosed.Type: GrantFiled: December 28, 2005Date of Patent: February 24, 2009Assignees: National Institute of Advanced Industrial Science and Technology, SII Nanotechnology Inc.Inventors: Hiroyuki Akinaga, Yasuyuki Semba, Hiroshi Yokoyama, Masatoshi Yasutake, Hiromi Kuramochi
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Publication number: 20080166560Abstract: The present invention provides a probe for a scanning magnetic force microscope having a resolution sufficient to allow observation of a magnetic storage medium with 1200 kFCI or higher recording densities, a method for producing the probe, and a method for forming a ferromagnetic alloy film on a carbon nanotube. In the context of the present invention, the probe for a scanning magnetic force microscope comprises a carbon nanotube whose surface is at least in part coated with a ferromagnetic alloy film consisting of any one of a Co—Fe alloy and a Co—Ni alloy, wherein the arithmetic mean roughness (Ra 10 ?m) of the surface of the ferromagnetic alloy film is controlled to 1.15 nm or less. A method for producing such probes for a scanning magnetic force microscope and a method for forming such a ferromagnetic alloy film on a carbon nanotube, so as to achieve such mean surface roughness by controlling the growth rate of the ferromagnetic alloy film within the range of 1.0 to 2.5 nm/min, is also disclosed.Type: ApplicationFiled: December 28, 2005Publication date: July 10, 2008Applicants: National Institute of Advanced Industrial Science and Technology, SII NanoTechnology Inc.Inventors: Hiroyuki Akinaga, Yasuyuki Semba, Hiroshi Yokoyama, Masatoshi Yasutake, Hiromi Kuramochi
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Publication number: 20080054243Abstract: The present invention provides switching elements having a readout margin suitable for data storage units of nonvolatile memories, which are obtained by improving the resistance ratio of metal oxide thin films having reversible variable resistance properties. The present invention provides switching elements having a metal oxide consisting of a transition metal and oxygen formed between a first electrode and a second electrode, by modifying one or more of the crystal structure, ionic valence number of metal element, and nonstoichiometricity of a stoichiometric compound consisted of the transition metal and oxygen.Type: ApplicationFiled: July 26, 2007Publication date: March 6, 2008Applicants: National Institute of Advanced Industrial Science and Technology, Sharp CorporationInventors: Hisashi Shima, Hiroyuki Akinaga, Fumiyoshi Takano, Yukio Tamai