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: 10332743
    Abstract: It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer including a channel formation region using an oxide semiconductor layer, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment for reducing impurities such as moisture (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer.
    Type: Grant
    Filed: August 1, 2017
    Date of Patent: June 25, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Toshinari Sasaki, Junichiro Sakata, Hiroki Ohara, Shunpei Yamazaki
  • Patent number: 10332996
    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: December 3, 2015
    Date of Patent: June 25, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Hiroki Ohara
  • Publication number: 20190172849
    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: Application
    Filed: February 7, 2019
    Publication date: June 6, 2019
    Inventors: Junichiro SAKATA, Toshinari SASAKI, Miyuki HOSOBA
  • Publication number: 20190148473
    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: Application
    Filed: December 18, 2018
    Publication date: May 16, 2019
    Inventors: Shunpei YAMAZAKI, Junichiro SAKATA, Hisao IKEDA, Yasuo NAKAMURA, Keiko SAITO
  • Patent number: 10283627
    Abstract: An object is to provide a highly reliable semiconductor device including a thin film transistor having stable electric characteristics. In addition, another object is to manufacture a highly reliable semiconductor device at low cost with high productivity. In a method for manufacturing a semiconductor device including a thin film transistor including an oxide semiconductor layer as a channel formation region, the oxide semiconductor layer is heated under a nitrogen atmosphere to lower its resistance, thereby forming a low-resistance oxide semiconductor layer. Further, resistance of a region of the low-resistance oxide semiconductor layer, which is overlapped with a gate electrode layer, is selectively increased, thereby forming a high-resistance oxide semiconductor layer. Resistance of the oxide semiconductor layer is increased by forming a silicon oxide film in contact with the oxide semiconductor layer by a sputtering method.
    Type: Grant
    Filed: July 10, 2014
    Date of Patent: May 7, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Toshinari Sasaki, Hiroki Ohara, Junichiro Sakata
  • Patent number: 10269941
    Abstract: It is an object to provide a highly reliable semiconductor device which includes a thin film transistor having stable electric characteristics. It is another object to manufacture a highly reliable semiconductor device at lower cost with high productivity. In a method for manufacturing a semiconductor device which includes a thin film transistor where a semiconductor layer having a channel formation region, a source region, and a drain region are formed using an oxide semiconductor layer, heat treatment (heat treatment for dehydration or dehydrogenation) is performed so as to improve the purity of the oxide semiconductor layer and reduce impurities such as moisture. Moreover, the oxide semiconductor layer subjected to the heat treatment is slowly cooled under an oxygen atmosphere.
    Type: Grant
    Filed: April 16, 2018
    Date of Patent: April 23, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Toshinari Sasaki, Junichiro Sakata, Hiroki Ohara, Shunpei Yamazaki
  • Patent number: 10243005
    Abstract: An object is to improve reliability of a semiconductor device. A semiconductor device including a driver circuit portion and a display portion (also referred to as a pixel portion) over the same substrate is provided. The driver circuit portion and the display portion include thin film transistors in which a semiconductor layer includes an oxide semiconductor; a first wiring; and a second wiring. The thin film transistors each include a source electrode layer and a drain electrode layer which each have a shape whose end portions are located on an inner side than end portions of the semiconductor layer. In the thin film transistor in the driver circuit portion, the semiconductor layer is provided between a gate electrode layer and a conductive layer. The first wiring and the second wiring are electrically connected in an opening provided in a gate insulating layer through an oxide conductive layer.
    Type: Grant
    Filed: September 15, 2016
    Date of Patent: March 26, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Masayuki Sakakura, Yoshiaki Oikawa, Kenichi Okazaki, Hotaka Maruyama
  • Patent number: 10236391
    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: May 31, 2018
    Date of Patent: March 19, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Junichiro Sakata, Takuya Hirohashi, Hideyuki Kishida
  • Patent number: 10211231
    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: November 30, 2017
    Date of Patent: February 19, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Junichiro Sakata, Toshinari Sasaki, Miyuki Hosoba
  • Publication number: 20190051754
    Abstract: Many of the physical properties of a silicon semiconductor have already been understood, whereas many of the physical properties of an oxide semiconductor have been still unclear. In particular, an adverse effect of an impurity on an oxide semiconductor has been still unclear. In view of the above, a structure is disclosed in which an impurity that influences electrical characteristics of a semiconductor device including an oxide semiconductor layer is prevented or is eliminated. A semiconductor device which includes a gate electrode, an oxide semiconductor layer, and a gate insulating layer provided between the gate electrode and the oxide semiconductor layer and in which the nitrogen concentration in the oxide semiconductor layer is 1×1020 atoms/cm3 or less is provided.
    Type: Application
    Filed: October 12, 2018
    Publication date: February 14, 2019
    Inventors: Junichiro SAKATA, Tetsunori MARUYAMA, Yuki IMOTO
  • Publication number: 20190051673
    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 in is preferably a non-integer number of greater than or equal to 1 and less than 50. 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: October 16, 2018
    Publication date: February 14, 2019
    Inventors: Shunichi ITO, Toshinari SASAKI, Miyuki HOSOBA, Junichiro SAKATA
  • Publication number: 20190035641
    Abstract: An object is to manufacture a highly reliable semiconductor device including a thin film transistor with 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 (for dehydration or dehydrogenation) is performed to improve the purity of the oxide semiconductor film and reduce impurities including moisture or the like. After that, slow cooling is performed under an oxygen atmosphere. Besides impurities including moisture or the like exiting in the oxide semiconductor film, heat treatment causes reduction of impurities including moisture or the like exiting in a gate insulating layer and those in interfaces between the oxide semiconductor film and films which are provided over and below the oxide semiconductor and in contact therewith.
    Type: Application
    Filed: October 1, 2018
    Publication date: January 31, 2019
    Inventors: Toshinari SASAKI, Junichiro SAKATA, Hiroki OHARA, Shunpei YAMAZAKI
  • Patent number: 10192946
    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 22, 2016
    Date of Patent: January 29, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Hisao Ikeda, Yasuo Nakamura, Keiko Saito
  • Publication number: 20190027377
    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: September 13, 2018
    Publication date: January 24, 2019
    Inventors: Shunpei YAMAZAKI, Junichiro SAKATA, Hiroki OHARA
  • Patent number: 10186619
    Abstract: An object is to provide a semiconductor device having stable electric characteristics in which an oxide semiconductor is used. An oxide semiconductor layer is subjected to heat treatment for dehydration or dehydrogenation treatment in a nitrogen gas or an inert gas atmosphere such as a rare gas (e.g., argon or helium) or under reduced pressure and to a cooling step for treatment for supplying oxygen in an atmosphere of oxygen, an atmosphere of oxygen and nitrogen, or the air (having a dew point of preferably lower than or equal to ?40° C., still preferably lower than or equal to ?50° C.) atmosphere. The oxide semiconductor layer is thus highly purified, whereby an i-type oxide semiconductor layer is formed. A semiconductor device including a thin film transistor having the oxide semiconductor layer is manufactured.
    Type: Grant
    Filed: September 15, 2016
    Date of Patent: January 22, 2019
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Miyuki Hosoba, Junichiro Sakata, Hiroki Ohara, Shunpei Yamazaki
  • Publication number: 20190019895
    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: Application
    Filed: September 5, 2018
    Publication date: January 17, 2019
    Inventors: Shunpei YAMAZAKI, Miyuki HOSOBA, Junichiro SAKATA, Hideaki KUWABARA
  • Publication number: 20180366326
    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: Application
    Filed: August 23, 2018
    Publication date: December 20, 2018
    Inventors: Toshinari SASAKI, Junichiro SAKATA, Hiroki OHARA, Shunpei YAMAZAKI
  • Publication number: 20180342538
    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: April 19, 2018
    Publication date: November 29, 2018
    Inventors: Shunpei YAMAZAKI, Toshinari SASAKI, Junichiro SAKATA, Masashi TSUBUKU
  • Patent number: 10141343
    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: April 6, 2017
    Date of Patent: November 27, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunichi Ito, Toshinari Sasaki, Miyuki Hosoba, Junichiro Sakata
  • Patent number: 10141450
    Abstract: An object is to provide a thin film transistor having favorable electric characteristics and a semiconductor device including the thin film transistor as a switching element. The thin film transistor includes a gate electrode formed over an insulating surface, a gate insulating film over the gate electrode, an oxide semiconductor film which overlaps with the gate electrode over the gate insulating film and which includes a layer where the concentration of one or a plurality of metals contained in the oxide semiconductor is higher than that in other regions, a pair of metal oxide films formed over the oxide semiconductor film and in contact with the layer, and a source electrode and a drain electrode in contact with the metal oxide films. The metal oxide films are formed by oxidation of a metal contained in the source electrode and the drain electrode.
    Type: Grant
    Filed: August 22, 2016
    Date of Patent: November 27, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Akiharu Miyanaga, Junichiro Sakata, Masayuki Sakakura, Masahiro Takahashi, Hideyuki Kishida, Shunpei Yamazaki