Patents by Inventor Yuki Imoto

Yuki Imoto 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: 10008588
    Abstract: The amount of water and hydrogen contained in an oxide semiconductor film is reduced, and oxygen is supplied sufficiently from a base film to the oxide semiconductor film in order to reduce oxygen deficiencies. A stacked base film is formed, a first heat treatment is performed, an oxide semiconductor film is formed over and in contact with the stacked base film, and a second heat treatment is performed. In the stacked base film, a first base film and a second base film are stacked in this order. The first base film is an insulating oxide film from which oxygen is released by heating. The second base film is an insulating metal oxide film. An oxygen diffusion coefficient of the second base film is smaller than that of the first base film.
    Type: Grant
    Filed: December 26, 2014
    Date of Patent: June 26, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yuki Imoto, Yuhei Sato
  • Patent number: 9941310
    Abstract: The silicon nitride layer 910 formed by plasma CVD using a gas containing a hydrogen compound such as silane (SiH4) and ammonia (NH3) is provided on and in direct contact with the oxide semiconductor layer 905 used for the resistor 354, and the silicon nitride layer 910 is provided over the oxide semiconductor layer 906 used for the thin film transistor 355 with the silicon oxide layer 909 serving as a barrier layer interposed therebetween. Therefore, a higher concentration of hydrogen is introduced into the oxide semiconductor layer 905 than into the oxide semiconductor layer 906. As a result, the resistance of the oxide semiconductor layer 905 used for the resistor 354 is made lower than that of the oxide semiconductor layer 906 used for the thin film transistor 355.
    Type: Grant
    Filed: October 5, 2016
    Date of Patent: April 10, 2018
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Jun Koyama, Junichiro Sakata, Tetsunori Maruyama, Yuki Imoto, Yuji Asano, Junichi Koezuka
  • Publication number: 20170307121
    Abstract: A female pipe coupling member includes a coupling body and a sleeve 138 disposed around a cylindrical peripheral wall portion of the coupling body. The sleeve has a locking element receiving hole extending therethrough from an inner peripheral surface to an outer peripheral surface. When the sleeve is in a locking element releasing position where the locking element receiving hole radially aligns with a locking element, the locking element is received in the locking element receiving hole to assume an unlocking position. The locking element receiving hole is configured to block the locking element from passing therethrough radially outward and thus holds the locking element in the unlocking position from outside.
    Type: Application
    Filed: July 12, 2017
    Publication date: October 26, 2017
    Inventor: Yuki IMOTO
  • Publication number: 20170307122
    Abstract: A slide valve set in a fluid passage and displaceable in a direction of a longitudinal axis of the fluid passage to open or close the fluid passage, the slide valve being simplified in structure and having a plurality of seal portions. The slide valve includes a cylindrical slide valve body set coaxially with the fluid passage, the slide valve body having an outer peripheral surface, an inner peripheral surface, and at least one through-hole extending through from the outer peripheral surface to the inner peripheral surface. The slide valve further includes a seal member having an annular outer seal portion located over the outer peripheral surface of the slide valve body, an annular inner seal portion located over the inner peripheral surface of the slide valve body, and a connecting portion located in the through-hole to connect together the outer seal portion and the inner seal portion.
    Type: Application
    Filed: July 10, 2017
    Publication date: October 26, 2017
    Inventor: Yuki IMOTO
  • Patent number: 9673306
    Abstract: The amount of water and hydrogen contained in an oxide semiconductor film is reduced, and oxygen is supplied sufficiently from a base film to the oxide semiconductor film in order to reduce oxygen deficiencies. A stacked base film is formed, a first heat treatment is performed, an oxide semiconductor film is formed over and in contact with the stacked base film, and a second heat treatment is performed. In the stacked base film, a first base film and a second base film are stacked in this order. The first base film is an insulating oxide film from which oxygen is released by heating. The second base film is an insulating metal oxide film. An oxygen diffusion coefficient of the second base film is smaller than that of the first base film.
    Type: Grant
    Filed: December 26, 2014
    Date of Patent: June 6, 2017
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yuki Imoto, Yuhei Sato
  • Publication number: 20170025448
    Abstract: The silicon nitride layer 910 formed by plasma CVD using a gas containing a hydrogen compound such as silane (SiH4) and ammonia (NH3) is provided on and in direct contact with the oxide semiconductor layer 905 used for the resistor 354, and the silicon nitride layer 910 is provided over the oxide semiconductor layer 906 used for the thin film transistor 355 with the silicon oxide layer 909 serving as a barrier layer interposed therebetween. Therefore, a higher concentration of hydrogen is introduced into the oxide semiconductor layer 905 than into the oxide semiconductor layer 906. As a result, the resistance of the oxide semiconductor layer 905 used for the resistor 354 is made lower than that of the oxide semiconductor layer 906 used for the thin film transistor 355.
    Type: Application
    Filed: October 5, 2016
    Publication date: January 26, 2017
    Inventors: Jun KOYAMA, Junichiro SAKATA, Tetsunori MARUYAMA, Yuki IMOTO, Yuji ASANO, Junichi KOEZUKA
  • Publication number: 20170016108
    Abstract: There have been cases where transistors formed using oxide semiconductors are inferior in reliability to transistors formed using amorphous silicon. Thus, in the present invention, a semiconductor device including a highly reliable transistor formed using an oxide semiconductor is manufactured. An oxide semiconductor film is deposited by a sputtering method, using a sputtering target including an oxide semiconductor having crystallinity, and in which the direction of the c-axis of a crystal is parallel to a normal vector of the top surface of the oxide semiconductor. The target is formed by mixing raw materials so that its composition ratio can obtain a crystal structure.
    Type: Application
    Filed: June 22, 2016
    Publication date: January 19, 2017
    Inventors: Shunpei YAMAZAKI, Tetsunori MARUYAMA, Yuki IMOTO, Hitomi SATO, Masahiro WATANABE, Mitsuo MASHIYAMA, Kenichi OKAZAKI, Motoki NAKASHIMA, Takashi SHIMAZU
  • Patent number: 9530872
    Abstract: An object is to provide a thin film transistor and a method for manufacturing the thin film transistor including an oxide semiconductor with a controlled threshold voltage, high operation speed, a relatively easy manufacturing process, and sufficient reliability. An impurity having influence on carrier concentration in the oxide semiconductor layer, such as a hydrogen atom or a compound containing a hydrogen atom such as H2O, may be eliminated. An oxide insulating layer containing a large number of defects such as dangling bonds may be formed in contact with the oxide semiconductor layer, such that the impurity diffuses into the oxide insulating layer and the impurity concentration in the oxide semiconductor layer is reduced. The oxide semiconductor layer or the oxide insulating layer in contact with the oxide semiconductor layer may be formed in a deposition chamber which is evacuated with use of a cryopump whereby the impurity concentration is reduced.
    Type: Grant
    Filed: January 2, 2014
    Date of Patent: December 27, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Akiharu Miyanaga, Masayuki Sakakura, Junichi Koezuka, Tetsunori Maruyama, Yuki Imoto
  • Publication number: 20160358950
    Abstract: The silicon nitride layer 910 formed by plasma CVD using a gas containing a hydrogen compound such as silane (SiH4) and ammonia (NH3) is provided on and in direct contact with the oxide semiconductor layer 905 used for the resistor 354, and the silicon nitride layer 910 is provided over the oxide semiconductor layer 906 used for the thin film transistor 355 with the silicon oxide layer 909 serving as a barrier layer interposed therebetween. Therefore, a higher concentration of hydrogen is introduced into the oxide semiconductor layer 905 than into the oxide semiconductor layer 906. As a result, the resistance of the oxide semiconductor layer 905 used for the resistor 354 is made lower than that of the oxide semiconductor layer 906 used for the thin film transistor 355.
    Type: Application
    Filed: August 22, 2016
    Publication date: December 8, 2016
    Inventors: Jun KOYAMA, Junichiro SAKATA, Tetsunori MARUYAMA, Yuki IMOTO, Yuji ASANO, Junichi KOEZUKA
  • Patent number: 9472676
    Abstract: A semiconductor device having excellent electric characteristics and a method for manufacturing the semiconductor device are provided. A method for manufacturing a semiconductor device includes the steps of: forming a gate electrode; forming a gate insulating film to cover the gate electrode; forming an oxide semiconductor film over the gate insulating film; forming a hydrogen permeable film over the oxide semiconductor film; forming a hydrogen capture film over the hydrogen permeable film; performing heat treatment to release hydrogen from the oxide semiconductor film; forming a source electrode and a drain electrode to be in contact with a part of the oxide semiconductor film; and removing an exposed portion of the hydrogen capture film to form a channel protective film formed of the hydrogen permeable film. A semiconductor device manufactured by the above method is also provided.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: October 18, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yuki Imoto, Tetsunori Maruyama, Yuta Endo
  • Publication number: 20160300952
    Abstract: A minute transistor is provided. A semiconductor device includes a semiconductor over a substrate, a first conductor and a second conductor over the semiconductor, a first insulator over the first conductor and the second conductor, a second insulator over the semiconductor, a third insulator over the second insulator, and a third conductor over the third insulator. The third insulator is in contact with a side surface of the first insulator. The semiconductor includes a first region where the semiconductor overlaps with a bottom surface of the first conductor, a second region where the semiconductor overlaps with a bottom surface of the second conductor, and a third region where the semiconductor overlaps with a bottom surface of the third conductor. The length between a top surface of the semiconductor and the bottom surface of the third conductor is longer than the length between the first region and the third region.
    Type: Application
    Filed: April 5, 2016
    Publication date: October 13, 2016
    Inventors: Satoshi TORIUMI, Takashi HAMADA, Tetsunori MARUYAMA, Yuki IMOTO, Yuji ASANO, Ryunosuke HONDA, Shunpei YAMAZAKI
  • Patent number: 9443888
    Abstract: The silicon nitride layer 910 formed by plasma CVD using a gas containing a hydrogen compound such as silane (SiH4) and ammonia (NH3) is provided on and in direct contact with the oxide semiconductor layer 905 used for the resistor 354, and the silicon nitride layer 910 is provided over the oxide semiconductor layer 906 used for the thin film transistor 355 with the silicon oxide layer 909 serving as a barrier layer interposed therebetween. Therefore, a higher concentration of hydrogen is introduced into the oxide semiconductor layer 905 than into the oxide semiconductor layer 906. As a result, the resistance of the oxide semiconductor layer 905 used for the resistor 354 is made lower than that of the oxide semiconductor layer 906 used for the thin film transistor 355.
    Type: Grant
    Filed: August 18, 2014
    Date of Patent: September 13, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Jun Koyama, Junichiro Sakata, Tetsunori Maruyama, Yuki Imoto, Yuji Asano, Junichi Koezuka
  • Patent number: 9397225
    Abstract: In the transistor including an oxide semiconductor film, which includes a film for capturing hydrogen from the oxide semiconductor film (a hydrogen capture film) and a film for diffusing hydrogen (a hydrogen permeable film), hydrogen is transferred from the oxide semiconductor film to the hydrogen capture film through the hydrogen permeable film by heat treatment. Specifically, a base film or a protective film of the transistor including an oxide semiconductor film has a stacked-layer structure of the hydrogen capture film and the hydrogen permeable film. At this time, the hydrogen permeable film is formed on a side which is in contact with the oxide semiconductor film. After that, hydrogen released from the oxide semiconductor film is transferred to the hydrogen capture film through the hydrogen permeable film by the heat treatment.
    Type: Grant
    Filed: January 22, 2015
    Date of Patent: July 19, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yuki Imoto, Tetsunori Maruyama, Yuta Endo
  • Patent number: 9382611
    Abstract: There have been cases where transistors formed using oxide semiconductors are inferior in reliability to transistors formed using amorphous silicon. Thus, in the present invention, a semiconductor device including a highly reliable transistor formed using an oxide semiconductor is manufactured. An oxide semiconductor film is deposited by a sputtering method, using a sputtering target including an oxide semiconductor having crystallinity, and in which the direction of the c-axis of a crystal is parallel to a normal vector of the top surface of the oxide semiconductor. The target is formed by mixing raw materials so that its composition ratio can obtain a crystal structure.
    Type: Grant
    Filed: June 5, 2012
    Date of Patent: July 5, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Tetsunori Maruyama, Yuki Imoto, Hitomi Sato, Masahiro Watanabe, Mitsuo Mashiyama, Kenichi Okazaki, Motoki Nakashima, Takashi Shimazu
  • Publication number: 20160125969
    Abstract: 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: Application
    Filed: January 12, 2016
    Publication date: May 5, 2016
    Inventors: Junichi KOEZUKA, Tetsunori MARUYAMA, Takayuki SAITO, Yuki IMOTO, Noriaki UTO, Yuta ENDO, Hitomi SHIONOYA, Takuya HIROHASHI, Shunpei YAMAZAKI
  • Patent number: 9260779
    Abstract: 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: Grant
    Filed: May 18, 2010
    Date of Patent: February 16, 2016
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Junichi Koezuka, Tetsunori Maruyama, Takayuki Saito, Yuki Imoto, Noriaki Uto, Yuta Endo, Hitomi Shionoya, Takuya Hirohashi, Shunpei Yamazaki
  • Publication number: 20160043230
    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 19, 2015
    Publication date: February 11, 2016
    Inventors: Junichiro SAKATA, Tetsunori MARUYAMA, Yuki IMOTO
  • Patent number: 9224838
    Abstract: An object is to provide an oxide semiconductor having stable electric characteristics and a semiconductor device including the oxide semiconductor. A manufacturing method of a semiconductor film by a sputtering method includes the steps of holding a substrate in a treatment chamber which is kept in a reduced-pressure state; heating the substrate at lower than 400° C.; introducing a sputtering gas from which hydrogen and moisture are removed in the state where remaining moisture in the treatment chamber is removed; and forming an oxide semiconductor film over the substrate with use of a metal oxide which is provided in the treatment chamber as a target. When the oxide semiconductor film is formed, remaining moisture in a reaction atmosphere is removed; thus, the concentration of hydrogen and the concentration of hydride in the oxide semiconductor film can be reduced. Thus, the oxide semiconductor film can be stabilized.
    Type: Grant
    Filed: April 24, 2014
    Date of Patent: December 29, 2015
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Akiharu Miyanaga, Masayuki Sakakura, Junichi Koezuka, Tetsunori Maruyama, Yuki Imoto
  • Patent number: 9219159
    Abstract: A method for forming an oxide semiconductor film having favorable semiconductor characteristics is provided. In addition, a method for manufacturing a semiconductor device having favorable electric characteristics, with use of the oxide semiconductor film is provided. A method for forming an oxide semiconductor film including the steps of forming an oxide semiconductor film, forming a hydrogen permeable film over and in contact with the oxide semiconductor film, forming a hydrogen capture film over and in contact with the hydrogen permeable film, and releasing hydrogen from the oxide semiconductor film by performing heat treatment. Further, in a method for manufacturing a semiconductor device, the method for forming an oxide semiconductor film is used.
    Type: Grant
    Filed: March 16, 2012
    Date of Patent: December 22, 2015
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Yuki Imoto, Tetsunori Maruyama, Toru Takayama
  • Patent number: 9202827
    Abstract: The silicon nitride layer 910 formed by plasma CVD using a gas containing a hydrogen compound such as silane (SiH4) and ammonia (NH3) is provided on and in direct contact with the oxide semiconductor layer 905 used for the resistor 354, and the silicon nitride layer 910 is provided over the oxide semiconductor layer 906 used for the thin film transistor 355 with the silicon oxide layer 909 serving as a barrier layer interposed therebetween. Therefore, a higher concentration of hydrogen is introduced into the oxide semiconductor layer 905 than into the oxide semiconductor layer 906. As a result, the resistance of the oxide semiconductor layer 905 used for the resistor 354 is made lower than that of the oxide semiconductor layer 906 used for the thin film transistor 355.
    Type: Grant
    Filed: December 18, 2009
    Date of Patent: December 1, 2015
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Jun Koyama, Junichiro Sakata, Tetsunori Maruyama, Yuki Imoto, Yuji Asano, Junichi Koezuka