Patents by Inventor Masashi Tsubuku

Masashi Tsubuku 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).

  • Publication number: 20210296371
    Abstract: To reduce a leakage current of a transistor so that malfunction of a logic circuit can be suppressed. The logic circuit includes a transistor which includes an oxide semiconductor layer having a function of a channel formation layer and in which an off current is 1×10?13 A or less per micrometer in channel width. A first signal, a second signal, and a third signal that is a clock signal are input as input signals. A fourth signal and a fifth signal whose voltage states are set in accordance with the first to third signals which have been input are output as output signals.
    Type: Application
    Filed: June 7, 2021
    Publication date: September 23, 2021
    Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Masashi TSUBUKU, Kosei NODA
  • Publication number: 20210257498
    Abstract: A semiconductor device includes a gate electrode, a gate insulating film which includes oxidized material containing silicon and covers the gate electrode, an oxide semiconductor film provided to be in contact with the gate insulating film and overlap with at least the gate electrode, and a source electrode and a drain electrode electrically connected to the oxide semiconductor film. In the oxide semiconductor film, a first region which is provided to be in contact with the gate insulating film and have a thickness less than or equal to 5 nm has a silicon concentration lower than or equal to 1.0 at. %, and a region in the oxide semiconductor film other than the first region has lower silicon concentration than the first region. At least the first region includes a crystal portion.
    Type: Application
    Filed: April 13, 2021
    Publication date: August 19, 2021
    Inventors: Tatsuya HONDA, Masashi TSUBUKU, Yusuke NONAKA, Takashi SHIMAZU, Shunpei YAMAZAKI
  • Patent number: 11094717
    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: May 21, 2020
    Date of Patent: August 17, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Toshinari Sasaki, Junichiro Sakata, Masashi Tsubuku
  • Publication number: 20210225887
    Abstract: A metal oxide film including a crystal part and having highly stable physical properties is provided. The size of the crystal part is less than or equal to 10 nm, which allows the observation of circumferentially arranged spots in a nanobeam electron diffraction pattern of the cross section of the metal oxide film when the measurement area is greater than or equal to 5 nm? and less than or equal to 10 nm?.
    Type: Application
    Filed: January 8, 2021
    Publication date: July 22, 2021
    Inventors: Masahiro TAKAHASHI, Takuya HIROHASHI, Masashi TSUBUKU, Noritaka ISHIHARA, Masashi OOTA
  • Patent number: 11069817
    Abstract: A display device including a pixel having a memory. The pixel includes at least a display element, a capacitor, an inverter, and a switch. The switch is controlled with a signal held in the capacitor and a signal output from the inverter so that voltage is supplied to the display element. The inverter and the switch can be constituted by transistors with the same polarity. A semiconductor layer included in the pixel may be formed using a light-transmitting material. Moreover, a gate electrode, a drain electrode, and a capacitor electrode may be formed using a light-transmitting conductive layer. The pixel is formed using a light-transmitting material in such a manner, whereby the display device can be a transmissive display device while including a pixel having a memory.
    Type: Grant
    Filed: October 29, 2019
    Date of Patent: July 20, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Hajime Kimura, Kengo Akimoto, Masashi Tsubuku, Toshinari Sasaki
  • Publication number: 20210210519
    Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.
    Type: Application
    Filed: March 19, 2021
    Publication date: July 8, 2021
    Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Atsushi HIROSE, Masashi TSUBUKU, Kosei NODA
  • Publication number: 20210210524
    Abstract: To reduce degradation of characteristics and reliability of a transistor including an oxide semiconductor as an active layer. A thin film transistor comprising: an active layer formed of an oxide semiconductor including at least indium and gallium; an electrode layer including an aluminum layer and partially formed on the active layer; and an interlayer insulating layer formed on the active layer, wherein a peak value of chlorine concentration at an interface between the interlayer insulating layer and the active layer is equal to or less than 2.0×1019 [atoms/cm3], and a peak value of aluminum concentration at an interface between the interlayer insulating layer and the active layer is equal to or less than 1.0×1020 [atoms/cm3].
    Type: Application
    Filed: March 23, 2021
    Publication date: July 8, 2021
    Applicant: Japan Display Inc.
    Inventors: Tatsuya TODA, Masashi TSUBUKU
  • Patent number: 11056515
    Abstract: To reduce a leakage current of a transistor so that malfunction of a logic circuit can be suppressed. The logic circuit includes a transistor which includes an oxide semiconductor layer having a function of a channel formation layer and in which an off current is 1×10?13 A or less per micrometer in channel width. A first signal, a second signal, and a third signal that is a clock signal are input as input signals. A fourth signal and a fifth signal whose voltage states are set in accordance with the first to third signals which have been input are output as output signals.
    Type: Grant
    Filed: March 12, 2020
    Date of Patent: July 6, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Jun Koyama, Masashi Tsubuku, Kosei Noda
  • Publication number: 20210202639
    Abstract: To sufficiently reduce an off-leakage current of a transistor including an oxide semiconductor as an active layer, provide a transistor having uniform characteristics when forming a large number of transistors on a large substrate, and reduce a load on a manufacturing process. A thin film transistor comprising: an active layer formed of an oxide semiconductor including at least indium and gallium; a gate electrode; a first gate insulating layer disposed between the active layer and the gate electrode on the gate electrode side; and a second gate insulating layer, which is a hydrogen block layer, disposed between the active layer and the gate electrode on the active layer side.
    Type: Application
    Filed: March 12, 2021
    Publication date: July 1, 2021
    Applicant: Japan Display Inc.
    Inventors: Masashi TSUBUKU, Tatsuya TODA
  • Publication number: 20210189547
    Abstract: A metal oxide film containing a crystal part is provided. Alternatively, a metal oxide film with highly stable physical properties is provided. Alternatively, a metal oxide film with improved electrical characteristics is provided. Alternatively, a metal oxide film with which field-effect mobility can be increased is provided. A metal oxide film including In, M (M is Al, Ga, Y, or Sn), and Zn includes a first crystal part and a second crystal part; the first crystal part has c-axis alignment; the second crystal part has no c-axis alignment; and the existing proportion of the second crystal part is higher than the existing proportion of the first crystal part.
    Type: Application
    Filed: December 7, 2020
    Publication date: June 24, 2021
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei YAMAZAKI, Junichi KOEZUKA, Kenichi OKAZAKI, Masashi TSUBUKU
  • Publication number: 20210175256
    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 27, 2020
    Publication date: June 10, 2021
    Inventors: Masayuki SAKAKURA, Yoshiaki OIKAWA, Shunpei YAMAZAKI, Junichiro SAKATA, Masashi TSUBUKU, Kengo AKIMOTO, Miyuki HOSOBA
  • Patent number: 11024516
    Abstract: An object is to provide a display device with excellent display characteristics, where a pixel circuit and a driver circuit provided over one substrate are formed using transistors which have different structures corresponding to characteristics of the respective circuits. The driver circuit portion includes a driver circuit transistor in which a gate electrode layer, a source electrode layer, and a drain electrode layer are formed using a metal film, and a channel layer is formed using an oxide semiconductor. The pixel portion includes a pixel transistor in which a gate electrode layer, a source electrode layer, and a drain electrode layer are formed using an oxide conductor, and a semiconductor layer is formed using an oxide semiconductor. The pixel transistor is formed using a light-transmitting material, and thus, a display device with higher aperture ratio can be manufactured.
    Type: Grant
    Filed: July 30, 2019
    Date of Patent: June 1, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Junichiro Sakata, Masashi Tsubuku, Kengo Akimoto, Miyuki Hosoba, Masayuki Sakakura, Yoshiaki Oikawa
  • Publication number: 20210159345
    Abstract: An oxide semiconductor film which has more stable electric conductivity is provided. The oxide semiconductor film comprises a crystalline region. The oxide semiconductor film has a first peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.4 nm?1 and less than or equal to 0.7 nm?1 in a region where a magnitude of a scattering vector is greater than or equal to 3.3 nm?1 and less than or equal to 4.1 nm?1. The oxide semiconductor film has a second peak of electron diffraction intensity with a full width at half maximum of greater than or equal to 0.45 nm?1 and less than or equal to 1.4 nm?1 in a region where a magnitude of a scattering vector is greater than or equal to 5.5 nm?1 and less than or equal to 7.1 nm?1.
    Type: Application
    Filed: February 4, 2021
    Publication date: May 27, 2021
    Inventors: Shunpei YAMAZAKI, Masashi TSUBUKU, Kengo AKIMOTO, Hiroki OHARA, Tatsuya HONDA, Takatsugu OMATA, Yusuke NONAKA, Masahiro TAKAHASHI, Akiharu MIYANAGA
  • Publication number: 20210151576
    Abstract: A thin film transistor comprising an active layer made of an oxide semiconductor containing indium and gallium, an electrode layer including a titanium layer formed on the active layer, wherein an indium concentration is equal to or less than 1.3 times an oxygen concentration in a range of 15 nm from an interface between the active layer and the electrode layer toward the active layer.
    Type: Application
    Filed: January 29, 2021
    Publication date: May 20, 2021
    Inventors: Takeshi SAKAI, Tatsuya TODA, Masashi TSUBUKU
  • Publication number: 20210151604
    Abstract: A thin film transistor comprising an active layer made of an oxide semiconductor containing at least indium and gallium; an electrode layer partially formed on the active layer; an oxide film insulating layer formed on the active layer and the electrode layer; and a nitride film insulating layer formed on the oxide film insulating layer. The thin film transistor further comprises an oxygen diffusion-inhibiting film partially overlapping with the active layer in a plan view between the oxide film insulating layer and the nitride film insulating layer.
    Type: Application
    Filed: January 29, 2021
    Publication date: May 20, 2021
    Inventors: Takashi OKADA, Masashi TSUBUKU
  • Publication number: 20210143281
    Abstract: An object is to reduce leakage current and parasitic capacitance of a transistor used for an LSI, a CPU, or a memory. A semiconductor integrated circuit such as an LSI, a CPU, or a memory is manufactured using a thin film transistor in which a channel formation region is formed using an oxide semiconductor which becomes an intrinsic or substantially intrinsic semiconductor by removing impurities which serve as electron donors (donors) from the oxide semiconductor and has larger energy gap than that of a silicon semiconductor. With use of a thin film transistor using a highly purified oxide semiconductor layer with sufficiently reduced hydrogen concentration, a semiconductor device with low power consumption due to leakage current can be realized.
    Type: Application
    Filed: September 2, 2020
    Publication date: May 13, 2021
    Inventors: Shunpei YAMAZAKI, Jun KOYAMA, Hiroyuki MIYAKE, Kei TAKAHASHI, Kouhei TOYOTAKA, Masashi TSUBUKU, Kosei NODA, Hideaki KUWABARA
  • Patent number: 11004983
    Abstract: An object is to provide a memory device including a memory element that can be operated without problems by a thin film transistor with a low off-state current. Provided is a memory device in which a memory element including at least one thin film transistor that includes an oxide semiconductor layer is arranged as a matrix. The thin film transistor including an oxide semiconductor layer has a high field effect mobility and low off-state current, and thus can be operated favorably without problems. In addition, the power consumption can be reduced. Such a memory device is particularly effective in the case where the thin film transistor including an oxide semiconductor layer is provided in a pixel of a display device because the memory device and the pixel can be formed over one substrate.
    Type: Grant
    Filed: January 31, 2020
    Date of Patent: May 11, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Masashi Tsubuku, Kosei Noda, Kouhei Toyotaka, Kazunori Watanabe, Hikaru Harada
  • Publication number: 20210119055
    Abstract: A semiconductor device comprising: an oxide semiconductor layer including indium; a gate electrode facing to the oxide semiconductor layer; a gate insulating layer between the oxide semiconductor layer and the gate electrode; a first conductive layer arranged above the oxide semiconductor layer and being in contact with the oxide semiconductor layer from above the oxide semiconductor layer; an oxide portion formed on the oxide semiconductor layer and at an edge of the first conductive layer, the oxide portion being a oxide of the first conductive layer.
    Type: Application
    Filed: September 29, 2020
    Publication date: April 22, 2021
    Inventors: Tatsuya TODA, Masashi TSUBUKU
  • Publication number: 20210091226
    Abstract: A semiconductor device includes a gate electrode on a substrate, a gate insulating film on the gate electrode, an oxide semiconductor film via the gate insulating film on the gate electrode, a source electrode and a drain electrode on the oxide semiconductor film, a protective film provided on the source electrode and the drain electrode; and a conductive layer provided on the protective film and overlapped on the oxide semiconductor layer. The protective film includes a first silicon oxide film and a first silicon nitride film. The first oxide film is in contact with the oxide semiconductor layer. The gate insulating film includes a second silicon nitride film and a second silicon oxide film. The second silicon oxide film is in contact with the oxide semiconductor layer. The oxide semiconductor layer has a first region located between the source electrode and the drain electrode in a plan view.
    Type: Application
    Filed: December 4, 2020
    Publication date: March 25, 2021
    Applicant: Japan Display Inc.
    Inventors: Masashi TSUBUKU, Michiaki SAKAMOTO, Takashi OKADA, Toshiki KANEKO, Tatsuya TODA
  • Patent number: 10957714
    Abstract: An object is to obtain a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range, using a thin film transistor in which an oxide semiconductor layer is used. An analog circuit is formed with the use of a thin film transistor including an oxide semiconductor which has a function as a channel formation layer, has a hydrogen concentration of 5×1019 atoms/cm3 or lower, and substantially functions as an insulator in the state where no electric field is generated. Thus, a semiconductor device having a high sensitivity in detecting signals and a wide dynamic range can be obtained.
    Type: Grant
    Filed: June 10, 2019
    Date of Patent: March 23, 2021
    Assignee: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei Yamazaki, Jun Koyama, Atsushi Hirose, Masashi Tsubuku, Kosei Noda