Patents by Inventor Junichiro Sakata

Junichiro Sakata 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).

  • Patent number: 10714503
    Abstract: An object is to provide a display device which operates stably with use of a transistor having stable electric characteristics. In manufacture of a display device using transistors in which an oxide semiconductor layer is used for a channel formation region, a gate electrode is further provided over at least a transistor which is applied to a driver circuit. In manufacture of a transistor in which an oxide semiconductor layer is used for a channel formation region, the oxide semiconductor layer is subjected to heat treatment so as to be dehydrated or dehydrogenated; thus, impurities such as moisture existing in an interface between the oxide semiconductor layer and the gate insulating layer provided below and in contact with the oxide semiconductor layer and an interface between the oxide semiconductor layer and a protective insulating layer provided on and in contact with the oxide semiconductor layer can be reduced.
    Type: Grant
    Filed: February 7, 2019
    Date of Patent: July 14, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Junichiro Sakata, Toshinari Sasaki, Miyuki Hosoba
  • Patent number: 10714358
    Abstract: A semiconductor device for high power application in which a novel semiconductor material having high mass productivity is provided. An oxide semiconductor film is formed, and then, first heat treatment is performed on the exposed oxide semiconductor film in order to reduce impurities such as moisture or hydrogen in the oxide semiconductor film. Next, in order to further reduce impurities such as moisture or hydrogen in the oxide semiconductor film, oxygen is added to the oxide semiconductor film by an ion implantation method, an ion doping method, or the like, and after that, second heat treatment is performed on the exposed oxide semiconductor film.
    Type: Grant
    Filed: November 21, 2019
    Date of Patent: July 14, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Hiroki Ohara
  • Publication number: 20200220029
    Abstract: An object is to improve reliability of a light-emitting device. A light-emitting device has a driver circuit portion including a transistor for a driver circuit and a pixel portion including a transistor for a pixel over one substrate. The transistor for the driver circuit and the transistor for the pixel are inverted staggered transistors each including an oxide semiconductor layer in contact with part of an oxide insulating layer. In the pixel portion, a color filter layer and a light-emitting element are provided over the oxide insulating layer. In the transistor for the driver circuit, a conductive layer overlapping with a gate electrode layer and the oxide semiconductor layer is provided over the oxide insulating layer. The gate electrode layer, a source electrode layer, and a drain electrode layer are formed using metal conductive films.
    Type: Application
    Filed: March 19, 2020
    Publication date: July 9, 2020
    Inventors: Shunpei YAMAZAKI, Junichiro SAKATA, Masayuki SAKAKURA, Yoshiaki OIKAWA, Kenichi OKAZAKI, Hotaka MARUYAMA
  • Patent number: 10700213
    Abstract: 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: Grant
    Filed: March 14, 2019
    Date of Patent: June 30, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Junichiro Sakata, Takuya Hirohashi, Hideyuki Kishida
  • Patent number: 10692894
    Abstract: An object is to control composition and a defect of an oxide semiconductor, another object is to increase a field effect mobility of a thin film transistor and to obtain a sufficient on-off ratio with a reduced off current. A solution is to employ an oxide semiconductor whose composition is represented by InMO3(ZnO)m, where M is one or a plurality of elements selected from Ga, Fe, Ni, Mn, Co, and Al, and m is preferably a non-integer number of greater than 0 and less than 1. The concentration of Zn is lower than the concentrations of In and M. The oxide semiconductor has an amorphous structure. Oxide and nitride layers can be provided to prevent pollution and degradation of the oxide semiconductor.
    Type: Grant
    Filed: October 16, 2018
    Date of Patent: June 23, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunichi Ito, Toshinari Sasaki, Miyuki Hosoba, Junichiro Sakata
  • Publication number: 20200185530
    Abstract: A semiconductor device which includes a thin film transistor having an oxide semiconductor layer and excellent electrical characteristics is provided. Further, a method for manufacturing a semiconductor device in which plural kinds of thin film transistors of different structures are formed over one substrate to form plural kinds of circuits and in which the number of steps is not greatly increased is provided. After a metal thin film is formed over an insulating surface, an oxide semiconductor layer is formed thereover. Then, oxidation treatment such as heat treatment is performed to oxidize the metal thin film partly or entirely. Further, structures of thin film transistors are different between a circuit in which emphasis is placed on the speed of operation, such as a logic circuit, and a matrix circuit.
    Type: Application
    Filed: February 13, 2020
    Publication date: June 11, 2020
    Inventors: Shunpei YAMAZAKI, Junichiro SAKATA, Jun KOYAMA
  • Patent number: 10680111
    Abstract: An object is to provide a semiconductor device having a structure in which parasitic capacitance between wirings can be efficiently reduced. In a bottom gate thin film transistor using an oxide semiconductor layer, an oxide insulating layer used as a channel protection layer is formed above and in contact with part of the oxide semiconductor layer overlapping with a gate electrode layer, and at the same time an oxide insulating layer covering a peripheral portion (including a side surface) of the stacked oxide semiconductor layer is formed. Further, a source electrode layer and a drain electrode layer are formed in a manner such that they do not overlap with the channel protection layer. Thus, a structure in which an insulating layer over the source electrode layer and the drain electrode layer is in contact with the oxide semiconductor layer is provided.
    Type: Grant
    Filed: September 5, 2018
    Date of Patent: June 9, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Miyuki Hosoba, Junichiro Sakata, Hideaki Kuwabara
  • Patent number: 10672915
    Abstract: An object is to improve reliability of a light-emitting device. A light-emitting device has a driver circuit portion including a transistor for a driver circuit and a pixel portion including a transistor for a pixel over one substrate. The transistor for the driver circuit and the transistor for the pixel are inverted staggered transistors each including an oxide semiconductor layer in contact with part of an oxide insulating layer. In the pixel portion, a color filter layer and a light-emitting element are provided over the oxide insulating layer. In the transistor for the driver circuit, a conductive layer overlapping with a gate electrode layer and the oxide semiconductor layer is provided over the oxide insulating layer. The gate electrode layer, a source electrode layer, and a drain electrode layer are formed using metal conductive films.
    Type: Grant
    Filed: July 12, 2016
    Date of Patent: June 2, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Masayuki Sakakura, Yoshiaki Oikawa, Kenichi Okazaki, Hotaka Maruyama
  • Patent number: 10665453
    Abstract: An object is to provide a high reliable semiconductor device including a thin film transistor having stable electric characteristics. In a method for manufacturing a semiconductor device including a thin film transistor in which an oxide semiconductor film is used for a semiconductor layer including a channel formation region, heat treatment (which is for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor film and reduce impurities such as moisture. Besides impurities such as moisture existing in the oxide semiconductor film, heat treatment causes reduction of impurities such as moisture existing in the gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor film and are in contact with the oxide semiconductor film.
    Type: Grant
    Filed: August 23, 2018
    Date of Patent: May 26, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Toshinari Sasaki, Junichiro Sakata, Hiroki Ohara, Shunpei Yamazaki
  • Patent number: 10665615
    Abstract: It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided.
    Type: Grant
    Filed: September 12, 2019
    Date of Patent: May 26, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Toshinari Sasaki, Junichiro Sakata, Masashi Tsubuku
  • Patent number: 10629627
    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-transimitting 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: March 16, 2017
    Date of Patent: April 21, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Masayuki Sakakura, Yoshiaki Oikawa, Shunpei Yamazaki, Junichiro Sakata, Masashi Tsubuku, Kengo Akimoto, Miyuki Hosoba
  • Publication number: 20200090950
    Abstract: A semiconductor device for high power application in which a novel semiconductor material having high mass productivity is provided. An oxide semiconductor film is formed, and then, first heat treatment is performed on the exposed oxide semiconductor film in order to reduce impurities such as moisture or hydrogen in the oxide semiconductor film. Next, in order to further reduce impurities such as moisture or hydrogen in the oxide semiconductor film, oxygen is added to the oxide semiconductor film by an ion implantation method, an ion doping method, or the like, and after that, second heat treatment is performed on the exposed oxide semiconductor film.
    Type: Application
    Filed: November 21, 2019
    Publication date: March 19, 2020
    Inventors: Shunpei YAMAZAKI, Junichiro SAKATA, Hiroki OHARA
  • Publication number: 20200066761
    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: Application
    Filed: November 4, 2019
    Publication date: February 27, 2020
    Inventors: Masayuki SAKAKURA, Yoshiaki OIKAWA, Shunpei YAMAZAKI, Junichiro SAKATA, Masashi TSUBUKU, Kengo AKIMOTO, Miyuki HOSOBA
  • Publication number: 20200058682
    Abstract: An aperture ratio of a semiconductor device is improved. A driver circuit and a pixel are provided over one substrate, and a first thin film transistor in the driver circuit and a second thin film transistor in the pixel each include a gate electrode layer, a gate insulating layer over the gate electrode layer, an oxide semiconductor layer over the gate insulating layer, source and drain electrode layers over the oxide semiconductor layer, and an oxide insulating layer in contact with part of the oxide semiconductor layer over the gate insulating layer, the oxide semiconductor layer, and the source and drain electrode layers. The gate electrode layer, the gate insulating layer, the oxide semiconductor layer, the source and drain electrode layers, and the oxide insulating layer of the second thin film transistor each have a light-transmitting property.
    Type: Application
    Filed: October 24, 2019
    Publication date: February 20, 2020
    Inventors: Shunpei YAMAZAKI, Junichiro SAKATA, Hiroyuki MIYAKE, Hideaki KUWABARA, Tatsuya TAKAHASHI
  • Patent number: 10566459
    Abstract: An object is to provide a semiconductor device including an oxide semiconductor with stable electric characteristics can be provided. An insulating layer having many defects typified by dangling bonds is formed over an oxide semiconductor layer with an oxygen-excess mixed region or an oxygen-excess oxide insulating layer interposed therebetween, whereby impurities in the oxide semiconductor layer, such as hydrogen or moisture (a hydrogen atom or a compound including a hydrogen atom such as H2O), are moved through the oxygen-excess mixed region or oxygen-excess oxide insulating layer and diffused into the insulating layer. Thus, the impurity concentration of the oxide semiconductor layer is reduced.
    Type: Grant
    Filed: October 27, 2017
    Date of Patent: February 18, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Akiharu Miyanaga, Masahiro Takahashi, Hideyuki Kishida, Junichiro Sakata
  • Patent number: 10529556
    Abstract: An object is to provide a deposition method in which a gallium oxide film is formed by a DC sputtering method. Another object is to provide a method for manufacturing a semiconductor device using a gallium oxide film as an insulating layer such as a gate insulating layer of a transistor. An insulating film is formed by a DC sputtering method or a pulsed DC sputtering method, using an oxide target including gallium oxide (also referred to as GaOX). The oxide target includes GaOX, and X is less than 1.5, preferably more than or equal to 0.01 and less than or equal to 0.5, further preferably more than or equal to 0.1 and less than or equal to 0.2. The oxide target has conductivity, and sputtering is performed in an oxygen gas atmosphere or a mixed atmosphere of an oxygen gas and a rare gas such as argon.
    Type: Grant
    Filed: June 29, 2017
    Date of Patent: January 7, 2020
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Makoto Furuno
  • Publication number: 20200006393
    Abstract: It is an object to manufacture a highly reliable display device using a thin film transistor having favorable electric characteristics and high reliability as a switching element. In a bottom gate thin film transistor including an amorphous oxide semiconductor, an oxide conductive layer having a crystal region is formed between an oxide semiconductor layer which has been dehydrated or dehydrogenated by heat treatment and each of a source electrode layer and a drain electrode layer which are formed using a metal material. Accordingly, contact resistance between the oxide semiconductor layer and each of the source electrode layer and the drain electrode layer can be reduced; thus, a thin film transistor having favorable electric characteristics and a highly reliable display device using the thin film transistor can be provided.
    Type: Application
    Filed: September 12, 2019
    Publication date: January 2, 2020
    Inventors: Shunpei YAMAZAKI, Toshinari SASAKI, Junichiro SAKATA, Masashi TSUBUKU
  • Publication number: 20190371824
    Abstract: An object is to control composition and a defect of an oxide semiconductor, another object is to increase a field effect mobility of a thin film transistor and to obtain a sufficient on-off ratio with a reduced off current. A solution is to employ an oxide semiconductor whose composition is represented by InMO3(ZnO)m, where M is one or a plurality of elements selected from Ga, Fe, Ni, Mn, Co, and Al, and m is preferably a non-integer number of greater than 0 and less than 1. The concentration of Zn is lower than the concentrations of In and M. The oxide semiconductor has an amorphous structure. Oxide and nitride layers can be provided to prevent pollution and degradation of the oxide semiconductor.
    Type: Application
    Filed: August 8, 2019
    Publication date: December 5, 2019
    Inventors: Shunichi ITO, Toshinari SASAKI, Miyuki HOSOBA, Junichiro SAKATA
  • Patent number: 10490618
    Abstract: The present invention provides a light-emitting device comprising a first light-emitting element that emits red light, a second light-emitting element that emits green light, a third light-emitting element that emits blue light, and a color filter, where the color filter comprises a first coloring layer that selectively transmits red light, a second coloring layer that selectively transmits green light, and a third coloring layer that selectively transmits blue light, the first to third light-emitting elements respectively correspond to the first to third coloring layers, wherein each of the first to third light-emitting elements has a first electrode, an electroluminescent layer on the first electrode, and a second electrode on the electroluminescent layer, and wherein the electroluminescent layer includes a layer in contact with the second electrode, and a metal oxide or a benzoxazole derivative is included in the layer in contact with the second electrode.
    Type: Grant
    Filed: December 18, 2018
    Date of Patent: November 26, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Hisao Ikeda, Yasuo Nakamura, Keiko Saito
  • Patent number: 10490420
    Abstract: A semiconductor device for high power application in which a novel semiconductor material having high mass productivity is provided. An oxide semiconductor film is formed, and then, first heat treatment is performed on the exposed oxide semiconductor film in order to reduce impurities such as moisture or hydrogen in the oxide semiconductor film. Next, in order to further reduce impurities such as moisture or hydrogen in the oxide semiconductor film, oxygen is added to the oxide semiconductor film by an ion implantation method, an ion doping method, or the like, and after that, second heat treatment is performed on the exposed oxide semiconductor film.
    Type: Grant
    Filed: September 13, 2018
    Date of Patent: November 26, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Hiroki Ohara