Patents by Inventor Kengo Akimoto

Kengo Akimoto 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).

  • Semiconductor device and manufacturing method thereof
    Patent number: 9660102
    Abstract: An object is to reduce to reduce variation in threshold voltage to stabilize electric characteristics of thin film transistors each using an oxide semiconductor layer. An object is to reduce an off current. The thin film transistor using an oxide semiconductor layer is formed by stacking an oxide semiconductor layer containing insulating oxide over the oxide semiconductor layer so that the oxide semiconductor layer and source and drain electrode layers are in contact with each other with the oxide semiconductor layer containing insulating oxide interposed therebetween; whereby, variation in threshold voltage of the thin film transistors can be reduced and thus the electric characteristics can be stabilized. Further, an off current can be reduced.
    Type: Grant
    Filed: April 6, 2015
    Date of Patent: May 23, 2017
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hiromichi Godo, Kengo Akimoto, Shunpei Yamazaki
  • Display device
    Patent number: 9659969
    Abstract: With an increase in the definition of a display device, the number of pixels is increased, and thus the numbers of gate lines and signal lines are increased. Due to the increase in the numbers of gate lines and signal lines, it is difficult to mount an IC chip having a driver circuit for driving the gate and signal lines by bonding or the like, which causes an increase in manufacturing costs. A pixel portion and a driver circuit for driving the pixel portion are formed over one substrate. At least a part of the driver circuit is formed using an inverted staggered thin film transistor in which an oxide semiconductor is used. The driver circuit as well as the pixel portion is provided over the same substrate, whereby manufacturing costs are reduced.
    Type: Grant
    Filed: March 6, 2015
    Date of Patent: May 23, 2017
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Kengo Akimoto, Atsushi Umezaki
  • MANUFACTURING METHOD FOR SEMICONDUCTOR DEVICE
    Publication number: 20170110337
    Abstract: A semiconductor device including an oxide conductor with high conductivity and high transmittance is provided. A manufacturing method for a semiconductor device includes the steps of: forming an oxide semiconductor over a first insulator; forming a second insulator over the first insulator and the oxide semiconductor; forming a first conductor over the second insulator; forming an etching mask over the first conductor; forming a second conductor including a region overlapping with the oxide semiconductor by etching the first conductor with use of the etching mask as a mask; removing the etching mask; and performing heat treatment after forming a hydrogen-containing layer over the second insulator and the second conductor.
    Type: Application
    Filed: October 17, 2016
    Publication date: April 20, 2017
    Inventors: Kengo AKIMOTO, Yukinori SHIMA
  • Semiconductor device and manufacturing method thereof
    Patent number: 9601516
    Abstract: The semiconductor device includes a driver circuit portion including a driver circuit and a pixel portion including a pixel. The pixel includes a gate electrode layer having a light-transmitting property, a gate insulating layer, a source electrode layer and a drain electrode layer each having a light-transmitting property provided over the gate insulating layer, an oxide semiconductor layer covering top surfaces and side surfaces of the source electrode layer and the drain electrode layer and provided over the gate electrode layer with the gate insulating layer therebetween, a conductive layer provided over part of the oxide semiconductor layer and having a lower resistance than the source electrode layer and the drain electrode layer, and an oxide insulating layer in contact with part of the oxide semiconductor layer.
    Type: Grant
    Filed: April 29, 2014
    Date of Patent: March 21, 2017
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masayuki Sakakura, Yoshiaki Oikawa, Shunpei Yamazaki, Junichiro Sakata, Masashi Tsubuku, Kengo Akimoto, Miyuki Hosoba
  • Light-Emitting Device and Lighting Device
    Publication number: 20170077444
    Abstract: A highly reliable light-emitting device which includes an organic EL element and is lightweight is provided. The light-emitting device includes a first organic resin layer; a first glass layer over the first organic resin layer; a light-emitting element over the first glass layer; a second glass layer over the light-emitting element; and a second organic resin layer over the second glass layer. The first organic resin layer and the first glass layer each have a property of transmitting visible light. The thickness of the first glass layer and the thickness of the second glass layer are independently greater than or equal to 25 ?m and less than or equal to 100 ?m. The light-emitting element includes a first electrode having a property of transmitting visible light, a layer containing a light-emitting organic compound, and a second electrode stacked in this order from the first glass layer side.
    Type: Application
    Filed: November 4, 2016
    Publication date: March 16, 2017
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei YAMAZAKI, Koichiro TANAKA, Masaaki HIROKI, Hisao IKEDA, Kengo AKIMOTO
  • Display device and method for manufacturing the same
    Patent number: 9589988
    Abstract: With an increase in the definition of a display device, the number of pixels is increased, and thus the numbers of gate lines and signal lines are increased. The increase in the numbers of gate lines and signal lines makes it difficult to mount an IC chip having a driver circuit for driving the gate line and the signal line by bonding or the like, which causes an increase in manufacturing costs. A pixel portion and a driver circuit driving the pixel portion are provided over the same substrate. The pixel portion and at least a part of the driver circuit are formed using thin film transistors in each of which an oxide semiconductor is used. Both the pixel portion and the driver circuit are provided over the same substrate, whereby manufacturing costs are reduced.
    Type: Grant
    Filed: October 16, 2014
    Date of Patent: March 7, 2017
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Kengo Akimoto, Atsushi Umezaki
  • Display device
    Patent number: 9570470
    Abstract: A display device including an oxide semiconductor, a protective circuit and the like having appropriate structures and a small occupied area is necessary. The protective circuit is formed using a non-linear element which includes a gate insulating film covering a gate electrode; a first oxide semiconductor layer which is over the gate insulating layer and overlaps with the gate electrode; and a first wiring layer and a second wiring layer each of which is formed by stacking a conductive layer and a second oxide semiconductor layer and whose end portions are over the first oxide semiconductor layer and overlap with the gate electrode. The gate electrode of the non-linear element is connected to a scan line or a signal line, the first wiring layer or the second wiring layer of the non-linear element is directly connected to the gate electrode layer so as to apply potential of the gate electrode.
    Type: Grant
    Filed: July 9, 2015
    Date of Patent: February 14, 2017
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Kengo Akimoto, Shigeki Komori, Hideki Uochi, Tomoya Futamura, Takahiro Kasahara
  • SEMICONDUCTOR DEVICE
    Publication number: 20170040409
    Abstract: A display device includes a pixel portion in which a pixel is arranged in a matrix, the pixel including an inverted staggered thin film transistor having a combination of at least two kinds of oxide semiconductor layers with different amounts of oxygen and having a channel protective layer over a semiconductor layer to be a channel formation region overlapping a gate electrode layer and a pixel electrode layer electrically connected to the inverted staggered thin film transistor. In the periphery of the pixel portion in this display device, a pad portion including a conductive layer made of the same material as the pixel electrode layer is provided. In addition, the conductive layer is electrically connected to a common electrode layer formed on a counter substrate.
    Type: Application
    Filed: October 18, 2016
    Publication date: February 9, 2017
    Inventors: Shunpei YAMAZAKI, Kengo AKIMOTO, Shigeki KOMORI, Hideki UOCHI, Rihito WADA, Yoko CHIBA
  • DISPLAY DEVICE
    Publication number: 20170032728
    Abstract: A display device having high visibility regardless of illuminance of external light is provided. A display device with reduced power consumption is provided. The display device includes a first light-receiving circuit including a first light-receiving element; and a pixel circuit including a display element. The first light-receiving circuit and the pixel circuit are formed over the same substrate. The gray level of the display element is changed according to a change in the amount of light to which the first light-receiving element is exposed. In particular, the gray level of the display element is decreased with a decrease in the amount of light exposure.
    Type: Application
    Filed: July 25, 2016
    Publication date: February 2, 2017
    Inventors: Yukinori SHIMA, Kengo AKIMOTO, Yuki OKAMOTO
  • SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME
    Publication number: 20170033228
    Abstract: In an active matrix display device, electric characteristics of thin film transistors included in a circuit are important, and performance of the display device depends on the electric characteristics. Thus, by using an oxide semiconductor film including In, Ga, and Zn for an inverted staggered thin film transistor, variation in electric characteristics of the thin film transistor can be reduced. Three layers of a gate insulating film, an oxide semiconductor layer and a channel protective layer are successively formed by a sputtering method without being exposed to air. Further, in the oxide semiconductor layer, the thickness of a region overlapping with the channel protective film is larger than that of a region in contact with a conductive film.
    Type: Application
    Filed: August 5, 2016
    Publication date: February 2, 2017
    Inventors: Shunpei YAMAZAKI, Hidekazu MIYAIRI, Kengo AKIMOTO, Kojiro SHIRAISHI
  • Semiconductor device and method for manufacturing the same
    Patent number: 9559212
    Abstract: An object is to increase field effect mobility of a thin film transistor including an oxide semiconductor. Another object is to stabilize electrical characteristics of the thin film transistor. In a thin film transistor including an oxide semiconductor layer, a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor is formed over the oxide semiconductor layer, whereby field effect mobility of the thin film transistor can be increased. Further, by forming a semiconductor layer or a conductive layer having higher electrical conductivity than the oxide semiconductor between the oxide semiconductor layer and a protective insulating layer of the thin film transistor, change in composition or deterioration in film quality of the oxide semiconductor layer is prevented, so that electrical characteristics of the thin film transistor can be stabilized.
    Type: Grant
    Filed: July 28, 2015
    Date of Patent: January 31, 2017
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hideaki Kuwabara, Kengo Akimoto, Toshinari Sasaki
  • SEMICONDUCTOR DEVICE AND METHOD FOR MANUFACTURING THE SAME
    Publication number: 20160380111
    Abstract: An embodiment is to include an inverted staggered (bottom gate structure) thin film transistor in which an oxide semiconductor film containing In, Ga, and Zn is used as a semiconductor layer and a buffer layer is provided between the semiconductor layer and a source and drain electrode layers. The buffer layer having higher carrier concentration than the semiconductor layer is provided intentionally between the source and drain electrode layers and the semiconductor layer, whereby an ohmic contact is formed.
    Type: Application
    Filed: September 13, 2016
    Publication date: December 29, 2016
    Inventors: Shunpei YAMAZAKI, Hidekazu MIYAIRI, Akiharu MIYANAGA, Kengo AKIMOTO, Kojiro SHIRAISHI
  • METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE
    Publication number: 20160372608
    Abstract: To provide a method by which a semiconductor device including a thin film transistor with excellent electric characteristics and high reliability is manufactured with a small number of steps. After a channel protective layer is formed over an oxide semiconductor film containing In, Ga, and Zn, a film having n-type conductivity and a conductive film are formed, and a resist mask is formed over the conductive film. The conductive film, the film having n-type conductivity, and the oxide semiconductor film containing In, Ga, and Zn are etched using the channel protective layer and gate insulating films as etching stoppers with the resist mask, so that source and drain electrode layers, a buffer layer, and a semiconductor layer are formed.
    Type: Application
    Filed: September 1, 2016
    Publication date: December 22, 2016
    Inventors: Hidekazu MIYAIRI, Kengo AKIMOTO, Yasuo NAKAMURA
  • Organic light-emitting device and lighting device with organic resin and glass substrate
    Patent number: 9502690
    Abstract: A highly reliable light-emitting device which includes an organic EL element and is lightweight is provided. The light-emitting device includes a first organic resin layer; a first glass layer over the first organic resin layer; a light-emitting element over the first glass layer; a second glass layer over the light-emitting element; and a second organic resin layer over the second glass layer. The first organic resin layer and the first glass layer each have a property of transmitting visible light. The light-emitting element includes a first electrode having a property of transmitting visible light, a layer containing a light-emitting organic compound, and a second electrode stacked in this order from the first glass layer side.
    Type: Grant
    Filed: December 15, 2011
    Date of Patent: November 22, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Koichiro Tanaka, Masaaki Hiroki, Hisao Ikeda, Kengo Akimoto
  • SEMICONDUCTOR DEVICE, DISPLAY DEVICE, AND ELECTRONIC APPLIANCE
    Publication number: 20160336456
    Abstract: 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: Application
    Filed: July 27, 2016
    Publication date: November 17, 2016
    Inventors: Shunpei YAMAZAKI, Masayuki SAKAKURA, Ryosuke WATANABE, Junichiro SAKATA, Kengo AKIMOTO, Akiharu MIYANAGA, Takuya HIROHASHI, Hideyuki KISHIDA
  • Semiconductor device and method for manufacturing the same
    Patent number: 9496406
    Abstract: An embodiment is to include an inverted staggered (bottom gate structure) thin film transistor in which an oxide semiconductor film containing In, Ga, and Zn is used as a semiconductor layer and a buffer layer is provided between the semiconductor layer and a source and drain electrode layers. The buffer layer having higher carrier concentration than the semiconductor layer is provided intentionally between the source and drain electrode layers and the semiconductor layer, whereby an ohmic contact is formed.
    Type: Grant
    Filed: July 12, 2012
    Date of Patent: November 15, 2016
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei Yamazaki, Hidekazu Miyairi, Akiharu Miyanaga, Kengo Akimoto, Kojiro Shiraishi
  • Process for producing unsaturated fatty acid-containing oils
    Patent number: 9493798
    Abstract: An edible oil obtained by culturing a microorganism belong to the genus Mortierella subgenus Mortierella in a medium containing a nitrogen source derived from soybean is discussed. The oils obtained have a low 24,25-methylenecholest-5-en-3?-ol content.
    Type: Grant
    Filed: July 10, 2006
    Date of Patent: November 15, 2016
    Assignee: SUNTORY HOLDINGS LIMITED
    Inventors: Kenichi Higashiyama, Kengo Akimoto, Sakayu Shimizu
  • Semiconductor device
    Patent number: 9478597
    Abstract: A display device includes a pixel portion in which a pixel is arranged in a matrix, the pixel including an inverted staggered thin film transistor having a combination of at least two kinds of oxide semiconductor layers with different amounts of oxygen and having a channel protective layer over a semiconductor layer to be a channel formation region overlapping a gate electrode layer and a pixel electrode layer electrically connected to the inverted staggered thin film transistor. In the periphery of the pixel portion in this display device, a pad portion including a conductive layer made of the same material as the pixel electrode layer is provided. In addition, the conductive layer is electrically connected to a common electrode layer formed on a counter substrate.
    Type: Grant
    Filed: September 10, 2009
    Date of Patent: October 25, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Kengo Akimoto, Shigeki Komori, Hideki Uochi, Rihito Wada, Yoko Chiba
  • Oxide semiconductor film and semiconductor device
    Patent number: 9478668
    Abstract: To provide an oxide semiconductor film having stable electric conductivity and a highly reliable semiconductor device having stable electric characteristics by using the oxide semiconductor film. The oxide semiconductor film contains indium (In), gallium (Ga), and zinc (Zn) and includes a c-axis-aligned crystalline region aligned in the direction parallel to a normal vector of a surface where the oxide semiconductor film is formed. Further, the composition of the c-axis-aligned crystalline region is represented by In1+?Ga1-?O3(ZnO)m (0<?<1 and m=1 to 3 are satisfied), and the composition of the entire oxide semiconductor film including the c-axis-aligned crystalline region is represented by InxGayO3(ZnO)m (0<x<2, 0<y<2, and m=1 to 3 are satisfied).
    Type: Grant
    Filed: April 3, 2012
    Date of Patent: October 25, 2016
    Assignee: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masahiro Takahashi, Kengo Akimoto, Shunpei Yamazaki
  • OXIDE SEMICONDUCTOR FILM AND SEMICONDUCTOR DEVICE
    Publication number: 20160308068
    Abstract: To provide an oxide semiconductor film having stable electric conductivity and a highly reliable semiconductor device having stable electric characteristics by using the oxide semiconductor film. The oxide semiconductor film contains indium (In), gallium (Ga), and zinc (Zn) and includes a c-axis-aligned crystalline region aligned in the direction parallel to a normal vector of a surface where the oxide semiconductor film is formed. Further, the composition of the c-axis-aligned crystalline region is represented by In1+?Ga1??O3(ZnO)m (0<?<1 and m=1 to 3 are satisfied), and the composition of the entire oxide semiconductor film including the c-axis-aligned crystalline region is represented by InxGayO3(ZnO)m (0<X<2, 0<y<2, and m=1 to 3 are satisfied).
    Type: Application
    Filed: June 30, 2016
    Publication date: October 20, 2016
    Inventors: Masahiro TAKAHASHI, Kengo AKIMOTO, Shunpei YAMAZAKI