Patents by Inventor Takuya Hirohashi
Takuya Hirohashi 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: 9748328Abstract: A highly reliable semiconductor device including an oxide semiconductor is provided. Provided is a semiconductor device including an oxide semiconductor layer, an insulating layer in contact with the oxide semiconductor layer, a gate electrode layer overlapping with the oxide semiconductor layer, and a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer. The oxide semiconductor layer includes a first region having a crystal whose size is less than or equal to 10 nm and a second region which overlaps with the insulating layer with the first region provided therebetween and which includes a crystal part whose c-axis is aligned in a direction parallel to a normal vector of the surface of the oxide semiconductor layer.Type: GrantFiled: March 8, 2016Date of Patent: August 29, 2017Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Masahiro Takahashi, Takuya Hirohashi, Masashi Tsubuku, Masashi Oota
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Publication number: 20170162718Abstract: A semiconductor device including a transistor having a reduced number of oxygen vacancies in a channel formation region of an oxide semiconductor with stable electrical characteristics or high reliability is provided. A gate insulating film is formed over a gate electrode; an oxide semiconductor layer is formed over the gate insulating film; an oxide layer is formed over the oxide semiconductor layer by a sputtering method to form an stacked-layer oxide film including the oxide semiconductor layer and the oxide layer; the stacked-layer oxide film is processed into a predetermined shape; a conductive film containing Ti as a main component is formed over the stacked-layer oxide film; the conductive film is etched to form source and drain electrodes and a depression portion on a back channel side; and portions of the stacked-layer oxide film in contact with the source and drain electrodes are changed to an n-type by heat treatment.Type: ApplicationFiled: February 23, 2017Publication date: June 8, 2017Inventors: Shunpei YAMAZAKI, Yasutaka NAKAZAWA, Masami JINTYOU, Junichi KOEZUKA, Kenichi OKAZAKI, Takuya HIROHASHI, Shunsuke ADACHI
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Patent number: 9673454Abstract: With a small amount of a conductive additive, an electrode for a storage battery including an active material layer which is highly filled with an active material is provided. The use of the electrode enables fabrication of a storage battery having high capacity per unit volume of the electrode. By using graphene as a conductive additive in an electrode for a storage battery including a positive electrode active material, a network for electron conduction through graphene is formed. Consequently, the electrode can include an active material layer in which particles of an active material are electrically connected to each other by graphene. Therefore, graphene is used as a conductive additive in an electrode for a sodium-ion secondary battery including an active material with low electric conductivity, for example, an active material with a band gap of 3.0 eV or more.Type: GrantFiled: February 14, 2014Date of Patent: June 6, 2017Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Tamae Moriwaka, Satoshi Seo, Takuya Hirohashi, Kunio Hosoya, Shunsuke Adachi
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Patent number: 9653728Abstract: An object is to provide graphene which has high conductivity and is permeable to ions of lithium or the like. Another object is to provide, with use of the graphene, a power storage device with excellent charging and discharging characteristics. Graphene having a hole inside a ring-like structure formed by carbon and nitrogen has conductivity and is permeable to ions of lithium or the like. The nitrogen concentration in graphene is preferably higher than or equal to 0.4 at. % and lower than or equal to 40 at. %. With use of such graphene, ions of lithium or the like can be preferably made to pass; thus, a power storage device with excellent charging and discharging characteristics can be provided.Type: GrantFiled: December 15, 2015Date of Patent: May 16, 2017Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Takuya Hirohashi, Teppei Oguni
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Patent number: 9601562Abstract: A highly reliable semiconductor device including an oxide semiconductor is provided. Provided is a semiconductor device including an oxide semiconductor layer, an insulating layer in contact with the oxide semiconductor layer, a gate electrode layer overlapping with the oxide semiconductor layer, and a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer. The oxide semiconductor layer includes a first region having a crystal whose size is less than or equal to 10 nm and a second region which overlaps with the insulating layer with the first region provided therebetween and which includes a crystal part whose c-axis is aligned in a direction parallel to a normal vector of the surface of the oxide semiconductor layer.Type: GrantFiled: March 8, 2016Date of Patent: March 21, 2017Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Masahiro Takahashi, Takuya Hirohashi, Masashi Tsubuku, Masashi Oota
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Patent number: 9583601Abstract: A method for manufacturing a semiconductor device including a transistor with stable electrical characteristics or high reliability is provided. A gate insulating film is formed over a gate electrode; an oxide semiconductor layer is formed over the gate insulating film; an oxide layer is formed over the oxide semiconductor layer to form a stacked-layer oxide film including the oxide semiconductor layer and the oxide layer; the stacked-layer oxide film is processed into a predetermined shape; a conductive film containing Ti is formed over the stacked-layer oxide film; the conductive film is etched to form source and drain electrodes; and regions in the oxide layer in contact with the source and drain electrodes are heat treated so as to have a low resistivity.Type: GrantFiled: January 21, 2016Date of Patent: February 28, 2017Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Yasutaka Nakazawa, Masami Jintyou, Junichi Koezuka, Kenichi Okazaki, Takuya Hirohashi, Shunsuke Adachi
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Patent number: 9577107Abstract: To improve crystallinity of an oxide semiconductor. To provide a crystalline oxide semiconductor film in which a crystallized region extends to the interface with a base or the vicinity of the interface, and to provide a method for forming the oxide semiconductor film. An oxide semiconductor film containing indium, gallium, and zinc is formed, and the oxide semiconductor film is irradiated with an energy beam, thereby being heated. Note that the oxide semiconductor film includes a c-axis aligned crystal region or microcrystal.Type: GrantFiled: March 13, 2014Date of Patent: February 21, 2017Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Akihisa Shimomura, Takahisa Ishiyama, Masaki Koyama, Erumu Kikuchi, Takuya Hirohashi, Masashi Oota
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Publication number: 20170033232Abstract: It is an object to provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a semiconductor device including an inverted staggered thin film transistor whose semiconductor layer is an oxide semiconductor layer, a buffer layer is provided over the oxide semiconductor layer. The buffer layer is in contact with a channel formation region of the semiconductor layer and source and drain electrode layers. A film of the buffer layer has resistance distribution. A region provided over the channel formation region of the semiconductor layer has lower electrical conductivity than the channel formation region of the semiconductor layer, and a region in contact with the source and drain electrode layers has higher electrical conductivity than the channel formation region of the semiconductor layer.Type: ApplicationFiled: October 13, 2016Publication date: February 2, 2017Inventors: Junichiro SAKATA, Takuya HIROHASHI, Hideyuki KISHIDA
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Publication number: 20160351721Abstract: In a semiconductor device using a transistor including an oxide semiconductor, a change in electrical characteristics is suppressed and reliability is improved. The semiconductor device includes a gate electrode over an insulating surface; an oxide semiconductor film overlapping with the gate electrode; a gate insulating film that is between the gate electrode and the oxide semiconductor film and in contact with the oxide semiconductor film; a protective film in contact with a surface of the oxide semiconductor film that is an opposite side of a surface in contact with the gate insulating film; and a pair of electrodes in contact with the oxide semiconductor film. The spin density of the gate insulating film or the protective film measured by electron spin resonance spectroscopy is lower than 1×1018 spins/cm3, preferably higher than or equal to 1×1017 spins/cm3 and lower than 1×1018 spins/cm3.Type: ApplicationFiled: August 10, 2016Publication date: December 1, 2016Inventors: Akiharu MIYANAGA, Yasuharu HOSAKA, Toshimitsu OBONAI, Junichi KOEZUKA, Motoki NAKASHIMA, Masahiro TAKAHASHI, Shunsuke ADACHI, Takuya HIROHASHI
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Publication number: 20160336456Abstract: In a channel protected thin film transistor in which a channel formation region is formed using an oxide semiconductor, an oxide semiconductor layer which is dehydrated or dehydrogenated by a heat treatment is used as an active layer, a crystal region including nanocrystals is included in a superficial portion in the channel formation region, and the rest portion is amorphous or is formed of a mixture of amorphousness/non-crystals and microcrystals, where an amorphous region is dotted with microcrystals. By using an oxide semiconductor layer having such a structure, a change to an n-type caused by entry of moisture or elimination of oxygen to or from the superficial portion and generation of a parasitic channel can be prevented and a contact resistance with a source and drain electrodes can be reduced.Type: ApplicationFiled: July 27, 2016Publication date: November 17, 2016Inventors: Shunpei YAMAZAKI, Masayuki SAKAKURA, Ryosuke WATANABE, Junichiro SAKATA, Kengo AKIMOTO, Akiharu MIYANAGA, Takuya HIROHASHI, Hideyuki KISHIDA
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Patent number: 9496414Abstract: It is an object to provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a semiconductor device including an inverted staggered thin film transistor whose semiconductor layer is an oxide semiconductor layer, a buffer layer is provided over the oxide semiconductor layer. The buffer layer is in contact with a channel formation region of the semiconductor layer and source and drain electrode layers. A film of the buffer layer has resistance distribution. A region provided over the channel formation region of the semiconductor layer has lower electrical conductivity than the channel formation region of the semiconductor layer, and a region in contact with the source and drain electrode layers has higher electrical conductivity than the channel formation region of the semiconductor layer.Type: GrantFiled: March 18, 2016Date of Patent: November 15, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Junichiro Sakata, Takuya Hirohashi, Hideyuki Kishida
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Patent number: 9443987Abstract: In a semiconductor device using a transistor including an oxide semiconductor, a change in electrical characteristics is suppressed and reliability is improved. The semiconductor device includes a gate electrode over an insulating surface; an oxide semiconductor film overlapping with the gate electrode; a gate insulating film that is between the gate electrode and the oxide semiconductor film and in contact with the oxide semiconductor film; a protective film in contact with a surface of the oxide semiconductor film that is an opposite side of a surface in contact with the gate insulating film; and a pair of electrodes in contact with the oxide semiconductor film. The spin density of the gate insulating film or the protective film measured by electron spin resonance spectroscopy is lower than 1×1018 spins/cm3, preferably higher than or equal to 1×1017 spins/cm3 and lower than 1×1018 spins/cm3.Type: GrantFiled: August 11, 2014Date of Patent: September 13, 2016Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.Inventors: Akiharu Miyanaga, Yasuharu Hosaka, Toshimitsu Obonai, Junichi Koezuka, Motoki Nakashima, Masahiro Takahashi, Shunsuke Adachi, Takuya Hirohashi
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Patent number: 9406808Abstract: In a channel protected thin film transistor in which a channel formation region is formed using an oxide semiconductor, an oxide semiconductor layer which is dehydrated or dehydrogenated by a heat treatment is used as an active layer, a crystal region including nanocrystals is included in a superficial portion in the channel formation region, and the rest portion is amorphous or is formed of a mixture of amorphousness/non-crystals and microcrystals, where an amorphous region is dotted with microcrystals. By using an oxide semiconductor layer having such a structure, a change to an n-type caused by entry of moisture or elimination of oxygen to or from the superficial portion and generation of a parasitic channel can be prevented and a contact resistance with a source and drain electrodes can be reduced.Type: GrantFiled: November 8, 2012Date of Patent: August 2, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Masayuki Sakakura, Ryosuke Watanabe, Junichiro Sakata, Kengo Akimoto, Akiharu Miyanaga, Takuya Hirohashi, Hideyuki Kishida
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Publication number: 20160218226Abstract: It is an object to provide a highly reliable semiconductor device with good electrical characteristics and a display device including the semiconductor device as a switching element. In a transistor including an oxide semiconductor layer, a needle crystal group provided on at least one surface side of the oxide semiconductor layer grows in a c-axis direction perpendicular to the surface and includes an a-b plane parallel to the surface, and a portion except for the needle crystal group is an amorphous region or a region in which amorphousness and microcrystals are mixed. Accordingly, a highly reliable semiconductor device with good electrical characteristics can be formed.Type: ApplicationFiled: April 5, 2016Publication date: July 28, 2016Inventors: Shunpei YAMAZAKI, Masayuki SAKAKURA, Ryosuke WATANABE, Junichiro SAKATA, Kengo AKIMOTO, Akiharu MIYANAGA, Takuya HIROHASHI, Hideyuki KISHIDA
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Publication number: 20160204269Abstract: It is an object to provide a highly reliable semiconductor device including a thin film transistor with stable electric characteristics. In a semiconductor device including an inverted staggered thin film transistor whose semiconductor layer is an oxide semiconductor layer, a buffer layer is provided over the oxide semiconductor layer. The buffer layer is in contact with a channel formation region of the semiconductor layer and source and drain electrode layers. A film of the buffer layer has resistance distribution. A region provided over the channel formation region of the semiconductor layer has lower electrical conductivity than the channel formation region of the semiconductor layer, and a region in contact with the source and drain electrode layers has higher electrical conductivity than the channel formation region of the semiconductor layer.Type: ApplicationFiled: March 18, 2016Publication date: July 14, 2016Inventors: Junichiro SAKATA, Takuya HIROHASHI, Hideyuki KISHIDA
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Publication number: 20160190576Abstract: Silicon oxide which is an oxide containing at least silicon, in which part of silicon is replaced by boron, aluminum, or gallium, is provided.Type: ApplicationFiled: December 17, 2015Publication date: June 30, 2016Inventors: Hiroyuki MIYAKE, Nobuhiro INOUE, Takuya HIROHASHI, Yuika SATO
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Publication number: 20160190232Abstract: A highly reliable semiconductor device including an oxide semiconductor is provided. Provided is a semiconductor device including an oxide semiconductor layer, an insulating layer in contact with the oxide semiconductor layer, a gate electrode layer overlapping with the oxide semiconductor layer, and a source electrode layer and a drain electrode layer electrically connected to the oxide semiconductor layer. The oxide semiconductor layer includes a first region having a crystal whose size is less than or equal to 10 nm and a second region which overlaps with the insulating layer with the first region provided therebetween and which includes a crystal part whose c-axis is aligned in a direction parallel to a normal vector of the surface of the oxide semiconductor layer.Type: ApplicationFiled: March 8, 2016Publication date: June 30, 2016Inventors: Shunpei YAMAZAKI, Masahiro TAKAHASHI, Takuya HIROHASHI, Masashi TSUBUKU, Masashi OOTA
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Publication number: 20160141397Abstract: A semiconductor device including a transistor having a reduced number of oxygen vacancies in a channel formation region of an oxide semiconductor with stable electrical characteristics or high reliability is provided. A gate insulating film is formed over a gate electrode; an oxide semiconductor layer is formed over the gate insulating film; an oxide layer is formed over the oxide semiconductor layer by a sputtering method to form an stacked-layer oxide film including the oxide semiconductor layer and the oxide layer; the stacked-layer oxide film is processed into a predetermined shape; a conductive film containing Ti as a main component is formed over the stacked-layer oxide film; the conductive film is etched to form source and drain electrodes and a depression portion on a back channel side; and portions of the stacked-layer oxide film in contact with the source and drain electrodes are changed to an n-type by heat treatment.Type: ApplicationFiled: January 21, 2016Publication date: May 19, 2016Inventors: Shunpei YAMAZAKI, Yasutaka NAKAZAWA, Masami JINTYOU, Junichi KOEZUKA, Kenichi OKAZAKI, Takuya HIROHASHI, Shunsuke ADACHI
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Publication number: 20160125969Abstract: An object is to provide a transparent conductive film having favorable transparency and conductivity at low cost. Another object is to reduce the resistivity of a transparent conductive film formed using conductive oxynitride including zinc and aluminum. Another object is to provide a transparent conductive film that is formed using conductive oxynitride including zinc and aluminum. When aluminum and nitrogen are made to be included in a transparent conductive film formed using oxide including zinc to form a transparent conductive film that is formed using conductive oxynitride including zinc and aluminum, the transparent conductive film can have reduced resistivity. Heat treatment after the formation of the transparent conductive film that is formed using conductive oxynitride including zinc and aluminum enables reduction in resistivity of the transparent conductive film.Type: ApplicationFiled: January 12, 2016Publication date: May 5, 2016Inventors: Junichi KOEZUKA, Tetsunori MARUYAMA, Takayuki SAITO, Yuki IMOTO, Noriaki UTO, Yuta ENDO, Hitomi SHIONOYA, Takuya HIROHASHI, Shunpei YAMAZAKI
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PARTICLE, ELECTRODE, POWER STORAGE DEVICE, ELECTRONIC DEVICE, AND METHOD FOR MANUFACTURING ELECTRODE
Publication number: 20160118658Abstract: To increase capacity per weight of a power storage device, a particle includes a first region, a second region in contact with at least part of a surface of the first region and located on the outside of the first region, and a third region in contact with at least part of a surface of the second region and located on the outside of the second region. The first and the second regions contain lithium and oxygen. At least one of the first region and the second region contains manganese. At least one of the first and the second regions contains an element M. The first region contains a first crystal having a layered rock-salt structure. The second region contains a second crystal having a layered rock-salt structure. An orientation of the first crystal is different from an orientation of the second crystal.Type: ApplicationFiled: October 22, 2015Publication date: April 28, 2016Inventors: Takahiro KAWAKAMI, Teruaki OCHIAI, Shuhei YOSHITOMI, Takuya HIROHASHI, Mako MOTOYOSHI, Yohei MOMMA, Junya GOTO