Patents by Inventor Suzunosuke Hiraishi

Suzunosuke Hiraishi 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: 20120241735
    Abstract: Provided is an oxide semiconductor film which has more stable electric characteristics and essentially consists of indium zinc oxide. In addition, provided is a highly reliable semiconductor device which has stable electric characteristics by using the oxide semiconductor film. The oxide semiconductor film essentially consisting of indium zinc oxide has a hexagonal crystal structure in which the a-b plane is substantially parallel to a surface of the oxide semiconductor film and a rhombohedral crystal structure in which the a-b plane is substantially parallel to the surface of the oxide semiconductor film.
    Type: Application
    Filed: March 15, 2012
    Publication date: September 27, 2012
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Tatsuya HONDA, Hiroshi KANEMURA, Kengo AKIMOTO, Suzunosuke HIRAISHI
  • Publication number: 20110315979
    Abstract: Manufactured is a transistor including an oxide semiconductor layer, a source electrode layer and a drain electrode layer overlapping with part of the oxide semiconductor layer, a gate insulating layer overlapping with the oxide semiconductor layer, the source electrode layer, and the drain electrode layer, and a gate electrode overlapping with part of the oxide semiconductor layer with the gate insulating layer provided therebetween, wherein, after the oxide semiconductor layer which is to be a channel formation region is irradiated with light and the light irradiation is stopped, a relaxation time of carriers in photoresponse characteristics of the oxide semiconductor layer has at least two kinds of modes: ?1 and ?2, ?1<?2 is satisfied, and ?2 is 300 seconds or less. In addition, a semiconductor device including the transistor is manufactured.
    Type: Application
    Filed: June 20, 2011
    Publication date: December 29, 2011
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Masashi Tsubuku, Takayuki Inoue, Suzunosuke Hiraishi, Erumu Kikuchi, Hiromichi Godo, Shuhei Yoshitomi, Koki Inoue, Akiharu Miyanaga, Shunpei Yamazaki
  • Publication number: 20110287591
    Abstract: An object is to provide a semiconductor device including an oxide semiconductor, which has stable electrical characteristics and high reliability. In a manufacturing process of a bottom-gate transistor including an oxide semiconductor layer, heat treatment in an atmosphere containing oxygen and heat treatment in vacuum are sequentially performed for dehydration or dehydrogenation of the oxide semiconductor layer. In addition, irradiation with light having a short wavelength is performed concurrently with the heat treatment, whereby elimination of hydrogen, OH, or the like is promoted. A transistor including an oxide semiconductor layer on which dehydration or dehydrogenation treatment is performed through such heat treatment has improved stability, so that variation in electrical characteristics of the transistor due to light irradiation or a bias-temperature stress (BT) test is suppressed.
    Type: Application
    Filed: May 18, 2011
    Publication date: November 24, 2011
    Applicant: Semiconductor Energy Laboratory Co., Ltd.
    Inventors: Shunpei YAMAZAKI, Ryosuke WATANABE, Suzunosuke HIRAISHI, Junichiro SAKATA
  • Publication number: 20110227082
    Abstract: An oxide semiconductor layer in which “safe” traps exist exhibits two kinds of modes in photoresponse characteristics. By using the oxide semiconductor layer, a transistor in which light deterioration is suppressed to the minimum and the electric characteristics are stable can be achieved. The oxide semiconductor layer exhibiting two kinds of modes in photoresponse characteristics has a photoelectric current value of 1 pA to 10 nA inclusive. When the average time ?1 until which carriers are captured by the “safe” traps is large enough, there are two kinds of modes in photoresponse characteristics, that is, a region where the current value falls rapidly and a region where the current value falls gradually, in the result of a change in photoelectric current over time.
    Type: Application
    Filed: March 15, 2011
    Publication date: September 22, 2011
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Takayuki Inoue, Masashi Tsubuku, Suzunosuke Hiraishi, Junichiro Sakata, Erumu Kikuchi, Hiromichi Godo, Akiharu Miyanaga, Shunpei Yamazaki
  • Publication number: 20110127524
    Abstract: Disclosed is a semiconductor device comprising a thin film transistor and wirings connected to the thin film transistor, in which the thin film transistor has a channel formation region in an oxide semiconductor layer, and a copper metal is used for at least one of a gate electrode, a source electrode, a drain electrode, a gate wiring, a source wiring, and a drain wiring. The extremely low off current of the transistor with the oxide semiconductor layer contributes to reduction in power consumption of the semiconductor device. Additionally, the use of the copper metal allows the combination of the semiconductor device with a display element to provide a display device with high display quality and negligible defects, which results from the low electrical resistance of the wirings and electrodes formed with the copper metal.
    Type: Application
    Filed: November 24, 2010
    Publication date: June 2, 2011
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei Yamazaki, Miyuki Hosoba, Suzunosuke Hiraishi
  • Publication number: 20110108833
    Abstract: An object is, in a thin film transistor including an oxide semiconductor layer, to reduce contact resistance between the oxide semiconductor layer and source and drain electrode layers electrically connected to the oxide semiconductor layer. The source and drain electrode layers have a stacked-layer structure of two or more layers in which a layer in contact with the oxide semiconductor layer is formed using a metal whose work function is lower than the work function of the oxide semiconductor layer or an alloy containing such a metal. Layers other than the layer in contact with the oxide semiconductor layer of the source and drain electrode layers are formed using an element selected from Al, Cr, Cu, Ta, Ti, Mo, or W, an alloy containing any of these elements as a component, an alloy containing any of these elements in combination, or the like.
    Type: Application
    Filed: November 2, 2010
    Publication date: May 12, 2011
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei Yamazaki, Suzunosuke Hiraishi, Kengo Akimoto, Junichiro Sakata
  • Publication number: 20110108834
    Abstract: An object is, in a thin film transistor including an oxide semiconductor layer, to reduce contact resistance between the oxide semiconductor layer and source and drain electrode layers electrically connected to the oxide semiconductor layer. The source and drain electrode layers have a stacked-layer structure of two or more layers in which a layer in contact with the oxide semiconductor layer is formed using an oxide of a metal whose work function is lower than the work function of the oxide semiconductor layer or an oxide of an alloy containing such a metal. Layers other than the layer in contact with the oxide semiconductor layer of the source and drain electrode layers are formed using an element selected from Al, Cr, Cu, Ta, Ti, Mo, or W, an alloy containing any of these elements as a component, an alloy containing any of these elements in combination, or the like.
    Type: Application
    Filed: November 2, 2010
    Publication date: May 12, 2011
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei Yamazaki, Suzunosuke Hiraishi, Kengo Akimoto, Junichiro Sakata
  • Publication number: 20110084269
    Abstract: An object is to reduce contact resistance between an oxide semiconductor layer and source and drain electrode layers electrically connected to the oxide semiconductor layer in a thin film transistor including the oxide semiconductor layer. The source and drain electrode layers have a stacked structure of two or more layers. In this stack of layers, a layer in contact with the oxide semiconductor layer is a thin indium layer or a thin indium-alloy layer. Note that the oxide semiconductor layer contains indium. A second layer or second and any of subsequent layers in the source and drain electrode layers are formed using an element selected from Al, Cr, Cu, Ta, Ti, Mo, and W, an alloy containing any of these elements as a component, an alloy containing any of these elements in combination, or the like.
    Type: Application
    Filed: October 6, 2010
    Publication date: April 14, 2011
    Applicant: SEMICONDUCTOR ENERGY LABORATORY CO., LTD.
    Inventors: Shunpei Yamazaki, Suzunosuke Hiraishi, Kengo Akimoto, Junichiro Sakata