Patents by Inventor Akihisa Shimomura
Akihisa Shimomura 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: 20160049521Abstract: A highly reliable semiconductor device including an oxide semiconductor is provided. Oxygen is supplied from a base insulating layer provided below an oxide semiconductor layer to a channel formation region, whereby oxygen vacancies which might be generated in the channel formation region are filled. Further, a protective insulating layer containing a small amount of hydrogen and functioning as a barrier layer having a low permeability to oxygen is formed over the gate electrode layer so as to cover side surfaces of an oxide layer and a gate insulating layer that are provided over the oxide semiconductor layer, whereby release of oxygen from the gate insulating layer and/or the oxide layer is prevented and generation of oxygen vacancies in a channel formation region is prevented.Type: ApplicationFiled: October 29, 2015Publication date: February 18, 2016Inventors: Sachiaki TEZUKA, Hideomi SUZAWA, Akihisa SHIMOMURA, Tetsuhiro TANAKA
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Patent number: 9257562Abstract: It is an object to provide a method of manufacturing a crystalline silicon device and a semiconductor device in which formation of cracks in a substrate, a base protective film, and a crystalline silicon film can be suppressed. First, a layer including a semiconductor film is formed over a substrate, and is heated. A thermal expansion coefficient of the substrate is 6×10?7/° C. to 38×10?7/° C., preferably 6×10?7/° C. to 31.8×10?7/° C. Next, the layer including the semiconductor film is irradiated with a laser beam to crystallize the semiconductor film so as to form a crystalline semiconductor film. Total stress of the layer including the semiconductor film is ?500 N/m to +50 N/m, preferably ?150 N/m to 0 N/m after the heating step.Type: GrantFiled: March 3, 2015Date of Patent: February 9, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Akihisa Shimomura, Hidekazu Miyairi, Fumito Isaka, Yasuhiro Jinbo, Junya Maruyama
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Patent number: 9231111Abstract: An object is to provide a semiconductor device that includes an oxide semiconductor and is suitable for a power device. An object is to provide a semiconductor device in which large current can flow. An object is to provide a highly reliable semiconductor device. A semiconductor device includes an oxide stack in which a first oxide layer, a first oxide semiconductor layer, a second oxide semiconductor layer, and a second oxide layer are stacked and has a structure in which a region that contains an element imparting conductivity and is provided in the first oxide semiconductor layer overlaps an electrode functioning as a source electrode and does not overlap an electrode functioning as a drain electrode.Type: GrantFiled: February 6, 2014Date of Patent: January 5, 2016Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Hideomi Suzawa, Akihisa Shimomura, Tetsuhiro Tanaka, Sachiaki Tezuka
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Patent number: 9202843Abstract: A highly productive method for sealing substrates with the use of glass frit is provided. A method for sealing substrates with the use of glass frit, which can be used for a substrate provided with a material having low heat resistance, is provided. A highly airtight sealed body which is manufactured by such a method is provided. A light-emitting device having high productivity and high reliability and a manufacturing method thereof are provided. A heat generation layer containing a conductive material which generates heat by induction heating is formed to overlap with a region where a paste including a frit material and a binder is applied. Alternatively, a conductive material which generates heat by induction heating is added to the paste itself. The paste is locally heated by induction heating to remove the binder included in the paste.Type: GrantFiled: August 25, 2014Date of Patent: December 1, 2015Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventor: Akihisa Shimomura
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Patent number: 9190527Abstract: A highly reliable semiconductor device including an oxide semiconductor is provided. Oxygen is supplied from a base insulating layer provided below an oxide semiconductor layer to a channel formation region, whereby oxygen vacancies which might be generated in the channel formation region are filled. Further, a protective insulating layer containing a small amount of hydrogen and functioning as a barrier layer having a low permeability to oxygen is formed over the gate electrode layer so as to cover side surfaces of an oxide layer and a gate insulating layer that are provided over the oxide semiconductor layer, whereby release of oxygen from the gate insulating layer and/or the oxide layer is prevented and generation of oxygen vacancies in a channel formation region is prevented.Type: GrantFiled: February 6, 2014Date of Patent: November 17, 2015Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Sachiaki Tezuka, Hideomi Suzawa, Akihisa Shimomura, Tetsuhiro Tanaka
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Publication number: 20150325708Abstract: A transistor capable of being driven at high operating frequency is provided. The transistor includes first to third oxide semiconductor layers, a gate insulating layer, a gate electrode layer, and a portion in which the first to third oxide semiconductor layers are sequentially stacked. Channel length is less than 100 nm, and cutoff frequency at a source-drain voltage of higher than or equal to 1 V and lower than or equal to 2 V is higher than 1 GHz. The gate insulating layer is in contact with a top surface of the third oxide semiconductor layer. The gate electrode layer partly overlaps with the portion with the gate insulating layer positioned therebetween. The second oxide semiconductor layer includes a plurality of c-axis aligned crystal parts and a region in which the concentration of hydrogen measured by secondary ion mass spectrometry is lower than 2×1020 atoms/cm3.Type: ApplicationFiled: May 5, 2015Publication date: November 12, 2015Inventors: Yuto YAKUBO, Suguru HONDO, Akihisa SHIMOMURA, Shunpei YAMAZAKI, Shuhei NAGATSUKA
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Publication number: 20150318359Abstract: A semiconductor device with favorable electrical characteristics is provided. In an oxide semiconductor film, a plurality of electron diffraction patterns are observed in such a manner that a surface over which the oxide semiconductor film is formed is irradiated with an electron beam having a probe diameter whose half-width is 1 nm while the position of the film and the position of the electron beam are relatively moved. The electron diffraction patterns include 50 or more electron diffraction patterns observed in different areas. The sum of the percentage of first electron diffraction patterns and the percentage of second electron diffraction patterns accounts for 100%. The first electron diffraction patterns account for 50% or more. The first electron diffraction pattern includes observation points that are not symmetry or observation points disposed in a circular pattern. The second electron diffraction pattern includes observation points corresponding to the vertices of a hexagon.Type: ApplicationFiled: March 17, 2015Publication date: November 5, 2015Inventors: Akihisa SHIMOMURA, Yuhei SATO, Yasumasa YAMANE, Shunpei YAMAZAKI, Kenichi OKAZAKI, Chiho KAWANABE
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Patent number: 9178069Abstract: A semiconductor device production system using a laser crystallization method is provided which can avoid forming grain boundaries in a channel formation region of a TFT, thereby preventing grain boundaries from lowering the mobility of the TFT greatly, from lowering ON current, and from increasing OFF current. Rectangular or stripe pattern depression and projection portions are formed on an insulating film. A semiconductor film is formed on the insulating film. The semiconductor film is irradiated with continuous wave laser light by running the laser light along the stripe pattern depression and projection portions of the insulating film or along the major or minor axis direction of the rectangle. Although continuous wave laser light is most preferred among laser light, it is also possible to use pulse oscillation laser light in irradiating the semiconductor film.Type: GrantFiled: July 31, 2009Date of Patent: November 3, 2015Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Atsuo Isobe, Shunpei Yamazaki, Koji Dairiki, Hiroshi Shibata, Chiho Kokubo, Tatsuya Arao, Masahiko Hayakawa, Hidekazu Miyairi, Akihisa Shimomura, Koichiro Tanaka, Mai Akiba
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Publication number: 20150243738Abstract: Favorable electrical characteristics are given to a semiconductor device. Furthermore, a semiconductor device having high reliability is provided. One embodiment of the present invention is an oxide semiconductor film having a plurality of electron diffraction patterns which are observed in such a manner that a surface where the oxide semiconductor film is formed is irradiated with an electron beam having a probe diameter whose half-width is 1 nm. The plurality of electron diffraction patterns include 50 or more electron diffraction patterns which are observed in different areas, the sum of the percentage of first electron diffraction patterns and the percentage of second electron diffraction patterns accounts for 100%, the first electron diffraction patterns account for 90% or more, the first electron diffraction pattern includes observed points which indicates that a c-axis is oriented in a direction substantially perpendicular to the surface where the oxide semiconductor film is formed.Type: ApplicationFiled: February 19, 2015Publication date: August 27, 2015Inventors: Akihisa SHIMOMURA, Yasumasa YAMANE, Yuhei SATO, Takahisa ISHIYAMA, Kenichi OKAZAKI, Chiho KAWANABE, Masashi OOTA, Noritaka ISHIHARA
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Patent number: 9112067Abstract: An object relates to an electrode of a semiconductor device or a method for manufacturing a semiconductor device, which includes a bonding step, and problems are: (1) high resistance of a semiconductor device due to the use of an Al electrode, (2) formation of an alloy by Al and Si, (3) high resistance of a film formed by a sputtering method, and (4) defective bonding in a bonding step which is caused if a bonding surface has a large unevenness. A semiconductor device includes a metal substrate or a substrate provided with a metal film, a copper (Cu) plating film over and bonded to the metal substrate or the metal film by employing a thermocompression bonding method, a barrier film over the Cu plating film, a single crystal silicon film over the barrier film, and an electrode layer over the single crystal silicon film.Type: GrantFiled: April 23, 2010Date of Patent: August 18, 2015Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Teruyuki Fujii, Kohei Ohshima, Junya Maruyama, Akihisa Shimomura
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Publication number: 20150221754Abstract: A transistor including an oxide semiconductor film, which has stable electric characteristics is provided. A transistor including an oxide semiconductor film, which has excellent on-state characteristics is also provided. A semiconductor device in which an oxide semiconductor film having low resistance is formed and the resistance of a channel region of the oxide semiconductor film is increased. Note that an oxide semiconductor film is subjected to a process for reducing the resistance to have low resistance. The process for reducing the resistance of the oxide semiconductor film may be a laser process or heat treatment at a temperature higher than or equal to 450° C. and lower than or equal to 740° C., for example. A process for increasing the resistance of the channel region of the oxide semiconductor film having low resistance may be performed by plasma oxidation or implantation of oxygen ions, for example.Type: ApplicationFiled: April 16, 2015Publication date: August 6, 2015Inventors: Suguru HONDO, Akihisa SHIMOMURA, Masaki KOYAMA, Motomu KURATA, Kazuya HANAOKA, Sho NAGAMATSU, Kosei NEI, Toru HASEGAWA
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Patent number: 9076839Abstract: An object of an embodiment of the present invention to be disclosed is to prevent oxygen from being taken in a single crystal semiconductor layer in laser irradiation even when crystallinity of the single crystal semiconductor layer is repaired by irradiation with a laser beam; and to make substantially equal or reduce an oxygen concentration in the semiconductor layer after the laser irradiation comparing before the laser irradiation. A single crystal semiconductor layer which is provided over a base substrate by bonding is irradiated with a laser beam, whereby the crystallinity of the single crystal semiconductor layer is repaired. The laser irradiation is performed under a reducing atmosphere or an inert atmosphere.Type: GrantFiled: May 12, 2011Date of Patent: July 7, 2015Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Akihisa Shimomura, Hideto Ohnuma, Junpei Momo, Shunpei Yamazaki
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Publication number: 20150187575Abstract: A method of forming an oxide semiconductor includes a step of depositing an oxide semiconductor layer over a substrate by using a sputtering apparatus in which in a target containing indium, an element M (aluminum, gallium, yttrium, or tin), zinc, and oxygen, the substrate which faces a surface of the target, and a magnet unit comprising a first magnet and a second magnet on a rear surface side of the target are provided. In the method, deposition is performed under a condition that a maximum intensity of a horizontal magnetic field is greater than or equal to 350 G and less than or equal to 2000 G in a plane where a vertical distance toward the substrate from a surface of the magnet unit is 10 mm.Type: ApplicationFiled: December 23, 2014Publication date: July 2, 2015Inventors: Shunpei Yamazaki, Akihisa Shimomura, Yuhei Sato, Yasumasa Yamane, Yoshinori Yamada, Tetsunori Maruyama
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Publication number: 20150179813Abstract: It is an object to provide a method of manufacturing a crystalline silicon device and a semiconductor device in which formation of cracks in a substrate, a base protective film, and a crystalline silicon film can be suppressed. First, a layer including a semiconductor film is formed over a substrate, and is heated. A thermal expansion coefficient of the substrate is 6×10?7/° C. to 38×10?7/° C., preferably 6×10?7/° C. to 31.8×10?7/° C. Next, the layer including the semiconductor film is irradiated with a laser beam to crystallize the semiconductor film so as to form a crystalline semiconductor film. Total stress of the layer including the semiconductor film is ?500 N/m to +50 N/m, preferably ?150 N/m to 0 N/m after the heating step.Type: ApplicationFiled: March 3, 2015Publication date: June 25, 2015Inventors: Akihisa SHIMOMURA, Hidekazu MIYAIRI, Fumito ISAKA, Yasuhiro JINBO, Junya MARUYAMA
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Publication number: 20150179803Abstract: To provide a transistor having a high on-state current. A semiconductor device includes a first insulator containing excess oxygen, a first oxide semiconductor over the first insulator, a second oxide semiconductor over the first oxide semiconductor, a first conductor and a second conductor which are over the second oxide semiconductor and are separated from each other, a third oxide semiconductor in contact with side surfaces of the first oxide semiconductor, a top surface and side surfaces of the second oxide semiconductor, a top surface of the first conductor, and a top surface of the second conductor, a second insulator over the third oxide semiconductor, and a third conductor facing a top surface and side surfaces of the second oxide semiconductor with the second insulator and the third oxide semiconductor therebetween. The first oxide semiconductor has a higher oxygen-transmitting property than the third oxide semiconductor.Type: ApplicationFiled: December 16, 2014Publication date: June 25, 2015Inventors: Shunpei Yamazaki, Akihisa Shimomura, Yuhei Sato, Yasumasa Yamane, Yoshitaka Yamamoto, Hideomi Suzawa, Tetsuhiro Tanaka, Yutaka Okazaki, Naoki Okuno, Takahisa Ishiyama
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Publication number: 20150179810Abstract: A change in electrical characteristics is suppressed and reliability in a semiconductor device using a transistor including an oxide semiconductor is improved. The semiconductor device includes an oxide semiconductor film over an insulating surface, an antioxidant film over the insulating surface and the oxide semiconductor film, a pair of electrodes in contact with the antioxidant film, a gate insulating film over the pair of electrodes, and a gate electrode which is over the gate insulating film and overlaps with the oxide semiconductor film. In the antioxidant film, a width of a region overlapping with the pair of electrodes is longer than a width of a region not overlapping with the pair of electrodes.Type: ApplicationFiled: December 18, 2014Publication date: June 25, 2015Inventors: Shunpei Yamazaki, Akihisa Shimomura, Yasumasa Yamane, Yuhei Sato, Tetsuhiro Tanaka, Masashi Tsubuku, Toshihiko Takeuchi, Ryo Tokumaru, Mitsuhiro Ichijo, Satoshi Toriumi, Takashi Ohtsuki, Toshiya Endo
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Patent number: 9048265Abstract: A transistor including an oxide semiconductor film, which has stable electric characteristics is provided. A transistor including an oxide semiconductor film, which has excellent on-state characteristics is also provided. A semiconductor device in which an oxide semiconductor film having low resistance is formed and the resistance of a channel region of the oxide semiconductor film is increased. Note that an oxide semiconductor film is subjected to a process for reducing the resistance to have low resistance. The process for reducing the resistance of the oxide semiconductor film may be a laser process or heat treatment at a temperature higher than or equal to 450° C. and lower than or equal to 740° C., for example. A process for increasing the resistance of the channel region of the oxide semiconductor film having low resistance may be performed by plasma oxidation or implantation of oxygen ions, for example.Type: GrantFiled: May 20, 2013Date of Patent: June 2, 2015Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Suguru Hondo, Akihisa Shimomura, Masaki Koyama, Motomu Kurata, Kazuya Hanaoka, Sho Nagamatsu, Kosei Nei, Toru Hasegawa
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Patent number: 9029184Abstract: To provide a resource-saving photoelectric conversion device with excellent photoelectric conversion characteristics. Thin part of a single crystal semiconductor substrate, typically a single crystal silicon substrate, is detached to structure a photoelectric conversion device using a thin single crystal semiconductor layer, which is the detached thin part of the single crystal semiconductor substrate. The thin part of the single crystal semiconductor substrate is detached by a method in which a substrate is irradiated with ions accelerated by voltage, or a method in which a substrate is irradiated with a laser beam which makes multiphoton absorption occur. A so-called tandem-type photoelectric conversion device is obtained by stacking a unit cell including a non-single-crystal semiconductor layer over the detached thin part of the single crystal semiconductor substrate.Type: GrantFiled: March 17, 2009Date of Patent: May 12, 2015Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Shunpei Yamazaki, Akihisa Shimomura
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Patent number: 8981379Abstract: It is an object to provide a method of manufacturing a crystalline silicon device and a semiconductor device in which formation of cracks in a substrate, a base protective film, and a crystalline silicon film can be suppressed. First, a layer including a semiconductor film is formed over a substrate, and is heated. A thermal expansion coefficient of the substrate is 6×10?7/° C. to 38×10?7/° C., preferably 6×10?7/° C. to 31.8×10?7/° C. Next, the layer including the semiconductor film is irradiated with a laser beam to crystallize the semiconductor film so as to form a crystalline semiconductor film. Total stress of the layer including the semiconductor film is ?500 N/m to +50 N/m, preferably ?150 N/m to 0 N/m after the heating step.Type: GrantFiled: September 22, 2011Date of Patent: March 17, 2015Assignee: Semiconductor Energy Laboratory Co., Ltd.Inventors: Akihisa Shimomura, Hidekazu Miyairi, Fumito Isaka, Yasuhiro Jinbo, Junya Maruyama
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Publication number: 20150064840Abstract: A method for forming a single crystal oxide film with high productivity is provided. Further, a method for forming a single crystal oxide film at a lower temperature is provided. In addition, a method for forming a single crystal oxide film by a simpler method is provided. An oxide film having crystal parts is formed over a formation surface, and the oxide film is single crystallized by performing heat treatment. Further, an oxide film having crystal parts in which the c-axis are aligned in a direction parallel to a normal direction of the formation surface or a normal direction of a surface of the oxide film and having no crystal grain boundary between the crystal parts is used as the oxide film formed over the formation surface.Type: ApplicationFiled: August 21, 2014Publication date: March 5, 2015Inventors: Akihisa SHIMOMURA, Masashi OOTA, Yoshinori YAMADA