Patents by Inventor Toshihiro Kugimiya

Toshihiro Kugimiya 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: 10475711
    Abstract: A quality evaluation method for an oxide semiconductor thin film includes: selecting a peak value having a largest calculated value and a time constant for the peak value among calculated values obtained by substituting each signal value for respective elapsed times after stopping excitation light irradiation and the corresponding elapsed time into the following Equation (1); and estimating, from the peak value and the time constant, an energy level of defect state and the defect density in the oxide semiconductor thin film: x=(signal value)×(elapsed time for the signal value)??Equation 1.
    Type: Grant
    Filed: April 26, 2017
    Date of Patent: November 12, 2019
    Assignee: Kobe Steel, Ltd.
    Inventors: Kazushi Hayashi, Mototaka Ochi, Toshihiro Kugimiya
  • Patent number: 10468535
    Abstract: Disclosed is an oxide for a semiconductor layer of a thin film transistor, which, when used in a thin film transistor that includes an oxide semiconductor in the semiconductor layer, imparts good switching characteristics and stress resistance to the transistor. Specifically disclosed is an oxide for a semiconductor layer of a thin film transistor, which is used for a semiconductor layer of a thin film transistor and contains at least one element selected from the group consisting of In, Ga and Zn and at least one element selected from the group X consisting of Al, Si, Ni, Ge, Sn, Hf, Ta and W.
    Type: Grant
    Filed: April 7, 2011
    Date of Patent: November 5, 2019
    Assignee: Kobe Steel, Ltd.
    Inventors: Shinya Morita, Toshihiro Kugimiya, Takeaki Maeda, Satoshi Yasuno, Yasuaki Terao, Aya Miki
  • Patent number: 10365520
    Abstract: Provided is a wiring structure for display device which does not generate hillocks even when exposed to high temperatures at levels around 450 to 600° C., has excellent high-temperature heat resistance, keeps electrical resistance (wiring resistance) of the entire wiring structure low, and further has excellent resistance to hydrofluoric acid. This wiring structure for a display device comprises a structure in which are laminated, in order from the substrate side, a first layer of an Al alloy that contains at least one chemical element selected from the group (group X) consisting of Ta, Nb, Re, Zr, W, Mo, V, Hf, Ti, Cr, and Pt and contains at least one rare earth element, and a second layer of an Al alloy nitride, or a nitride of at least one chemical element selected from the group Y consisted of Ti, Mo, Al, Ta, Nb, Re, Zr, W, V, Hf, and Cr.
    Type: Grant
    Filed: September 3, 2012
    Date of Patent: July 30, 2019
    Assignee: Kobe Steel, Ltd.
    Inventors: Hiroyuki Okuno, Toshihiro Kugimiya
  • Publication number: 20190122941
    Abstract: A quality evaluation method for an oxide semiconductor thin film includes: selecting a peak value having a largest calculated value and a time constant for the peak value among calculated values obtained by substituting each signal value for respective elapsed times after stopping excitation light irradiation and the corresponding elapsed time into the following Equation (1); and estimating, from the peak value and the time constant, an energy level of defect state and the defect density in the oxide semiconductor thin film: x=(signal value)×(elapsed time for the signal value)??Equation 1.
    Type: Application
    Filed: April 26, 2017
    Publication date: April 25, 2019
    Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.)
    Inventors: Kazushi HAYASHI, Mototaka OCHI, Toshihiro KUGIMIYA
  • Publication number: 20190123207
    Abstract: A thin film transistor includes at least an oxide semiconductor layer, a gate insulating film, a gate electrode, a source-drain electrode, and a protective film in this order on a substrate and further includes a protective layer. The oxide semiconductor layer includes an oxide constituted of In, Ga, Zn, Sn, and O. The atomic ratio of each metal element in the oxide semiconductor layer satisfies the following relationships: 0.09?Sn/(In+Ga+Zn+Sn)?0.25, 0.15?In/(In+Ga+Zn+Sn)?0.40, 0.07?Ga/(In+Ga+Zn+Sn)?0.20, and 0.35?Zn/(In+Ga+Zn+Sn)?0.55. The protective layer contains SiNx. The thin film transistor has a mobility of 15 cm2/Vs or more.
    Type: Application
    Filed: April 3, 2017
    Publication date: April 25, 2019
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Hiroshi GOTO, Mototaka OCHI, Takumi KITAYAMA, Toshihiro KUGIMIYA
  • Patent number: 10256091
    Abstract: The oxide of the present invention for thin-film transistors is an In—Zn—Sn-based oxide containing In, Zn, and Sn, wherein when the respective contents (atomic %) of metal elements contained in the In—Zn—Sn-based oxide are expressed by [Zn], [Sn], and [In], the In—Zn—Sn-based oxide fulfills the following expressions (2) and (4) when [In]/([In]+[Sn])?0.5; or the following expressions (1), (3), and (4) when [In]/([In]+[Sn])>0.5. [In]/([In]+[Zn]+[Sn])?0.3??(1), [In]/([In]+[Zn]+[Sn])?1.4×{[Zn]/([Zn]+[Sn])}?0.5??(2), [Zn]/([In]+[Zn]+[Sn])?0.83??(3), and 0.1?[In]/([In]+[Zn]+[Sn])??(4). According to the present invention, oxide thin films for thin-film transistors can be obtained, which provide TFTs with excellent switching characteristics, and which have high sputtering rate in the sputtering and properly controlled etching rate in the wet etching.
    Type: Grant
    Filed: October 11, 2016
    Date of Patent: April 9, 2019
    Assignees: Kobe Steel, Ltd., Samsung Display Co., Ltd.
    Inventors: Hiroaki Tao, Aya Miki, Shinya Morita, Satoshi Yasuno, Toshihiro Kugimiya, Jae Woo Park, Je Hun Lee, Byung Du Ahn, Gun Hee Kim
  • Publication number: 20190067489
    Abstract: Disclosed herein is a thin film transistor including at least an oxide semiconductor layer, a gate insulting film, a gate electrode, a source-drain electrode and a protective film in this order on a substrate and further including a protective layer. The oxide semiconductor layer includes an oxide constituted of In, Ga, Sn and O and an atomic ratio of each metal element satisfies the following relationships: 0.30?In/(In+Ga+Sn)?0.50, 0.19?Ga/(In+Ga+Sn)?0.30 and 0.24?Sn/(In+Ga+Sn)?0.45. The protective layer contains SiNx, and mobility is 35 cm2/Vs or more.
    Type: Application
    Filed: April 3, 2017
    Publication date: February 28, 2019
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Hiroshi GOTO, Mototaka OCHI, Takumi KITAYAMA, Toshihiro KUGIMIYA
  • Publication number: 20190064569
    Abstract: Disclosed is an antistatic film having a light-transmissive property provided on a light-transmissive member, comprising In, Zn, Sn and O.
    Type: Application
    Filed: February 28, 2017
    Publication date: February 28, 2019
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Toshihiro KUGIMIYA, Mototaka OCHI, Ayuko KAWAKAMI
  • Publication number: 20190051758
    Abstract: An oxide semiconductor layer in a thin-film transistor includes In, Ga, Zn and Sn. The respective ratios of the metal elements to a total (In+Ga+Zn+Sn) of all the metal elements in the oxide semiconductor layer are: In: 20 to 45 atom %, Ga: 5 to 20 atom %, Zn: 30 to 60 atom %, and Sn: 9 to 25 atom %.
    Type: Application
    Filed: February 2, 2017
    Publication date: February 14, 2019
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Mototaka OCHI, Kohei NISHIYAMA, Hiroshi GOTO, Toshihiro KUGIMIYA
  • Patent number: 10090208
    Abstract: Provided are: a method for measuring and evaluating (predicting or estimating) stress stability of an oxide semiconductor thin film in a contactless manner; and a quality control method for an oxide semiconductor. This evaluation method comprises a first step and a second step. The first step includes: subjecting an oxide semiconductor thin film to irradiation with both excitation light and microwave radiation; stopping the irradiation with the excitation light after the maximum intensity of reflected wave of the microwave radiation, which varies with the irradiation of the excitation light, from the thin film has been observed; and thereafter measuring a variation in the reflectance with which the microwave radiation is reflected by the thin film. The second step includes: calculating, from the variation in the reflectance, a parameter that corresponds to slow attenuation observed about 1 ?s after the stopping; and thus evaluating the stress stability of the oxide semiconductor.
    Type: Grant
    Filed: January 9, 2014
    Date of Patent: October 2, 2018
    Assignee: Kobe Steel, Ltd.
    Inventors: Tomoya Kishi, Kazushi Hayashi, Toshihiro Kugimiya
  • Patent number: 9816944
    Abstract: The present invention provides a method for accurately and easily measuring/evaluating/predicting/estimating the electrical resistance of an oxide semiconductor thin film, and a method for managing the film quality. The method for evaluating an oxide semiconductor thin film includes: a first step for irradiating, with excitation light and microwave, a sample on which an oxide semiconductor thin film is formed, measuring the maximum value of the reflected microwave by the thin film which changes due to the excitation light irradiation, then stopping the excitation light irradiation and measuring the change in reflectivity of the microwave from the thin film after the excitation light irradiation has been stopped; and a second step for calculating a parameter corresponding to the slow decay observed after the excitation light irradiation has been stopped from the change in the reflectivity and evaluating the electrical resistivity of the oxide semiconductor thin film.
    Type: Grant
    Filed: December 1, 2014
    Date of Patent: November 14, 2017
    Assignee: Kobe Steel, Ltd.
    Inventors: Kazushi Hayashi, Aya Miki, Toshihiro Kugimiya, Nobuyuki Kawakami
  • Patent number: 9780005
    Abstract: Provided is a method for reliably and simply evaluating the quality of an oxide semiconductor thin film and a laminated body having a protective film on the surface of this oxide semiconductor thin film. Also provided is a method for reliably and simply managing the quality of an oxide semiconductor thin film.
    Type: Grant
    Filed: July 6, 2015
    Date of Patent: October 3, 2017
    Assignee: Kobe Steel, Ltd.
    Inventors: Nobuyuki Kawakami, Kazushi Hayashi, Toshihiro Kugimiya, Mototaka Ochi
  • Publication number: 20170194218
    Abstract: Provided is a method for reliably and simply evaluating the quality of an oxide semiconductor thin film and a laminated body having a protective film on the surface of this oxide semiconductor thin film. Also provided is a method for reliably and simply managing the quality of an oxide semiconductor thin film.
    Type: Application
    Filed: July 6, 2015
    Publication date: July 6, 2017
    Applicant: Kabushiki Kaisha Kobe Seiko Sho (Kobe Steel, Ltd.)
    Inventors: Nobuyuki KAWAKAMI, Kazushi HAYASI, Toshihiro KUGIMIYA, Mototaka OCHI
  • Publication number: 20170170029
    Abstract: This thin film transistor has a gate electrode, a gate insulating film, an oxide semiconductor thin film, an etch stop layer for protecting the oxide semiconductor thin film, a source and drain electrodes, and a passivation film in this order on a substrate. The oxide semiconductor thin film is formed of an oxide configured from In, Ga and Sn as metal elements, and O, and has an amorphous structure, and the etch stop layer and/or the passivation film includes SiNx. The thin film transistor has an extremely high mobility of approximately 40 cm2/Vs or more.
    Type: Application
    Filed: August 6, 2015
    Publication date: June 15, 2017
    Applicant: KABUSHIKI KAISHA KOBE SEIKO SHO(KOBE STEEL, LTD.)
    Inventors: Mototaka OCHI, Yasuyuki TAKANASHI, Aya MIKI, Hiroshi GOTO, Toshihiro KUGIMIYA
  • Patent number: 9660103
    Abstract: This thin film transistor comprises, on a substrate, at least a gate electrode, a gate insulating film, an oxide semiconductor layer, a source-drain electrode, and two or more protective films. The oxide semiconductor layer comprises Sn, O and one or more elements selected from the group consisting of In, Ga and Zn. In addition, the two or more protective films are composed of at least a first protective film that is in contact with the oxide semiconductor film, and one or more second protective films other than the first protective film. The first protective film is a SiOx film having a hydrogen concentration of 3.5 atomic % or lower.
    Type: Grant
    Filed: June 24, 2014
    Date of Patent: May 23, 2017
    Assignee: Kobe Steel, Ltd.
    Inventors: Mototaka Ochi, Shinya Morita, Yasuyuki Takanashi, Hiroshi Goto, Toshihiro Kugimiya
  • Patent number: 9647126
    Abstract: Provided is an oxide semiconductor configured to be used in a thin film transistor having high field-effect mobility; a small shift in threshold voltages against light and bias stress; excellent stress resistance. The oxide semiconductor has also excellent resistance to a wet-etchant for patterning of a source-drain electrode. The oxide semiconductor comprises In, Zn, Ga, Sn and O, and satisfies the requirements represented by expressions (1) to (4) shown below, wherein [In], [Zn], [Ga], and [Sn] represent content (in atomic %) of each of the elements relative to the total content of all the metal elements other than oxygen in the oxide. (1.67×[Zn]+1.67×[Ga])?100??(1) {([Zn]/0.95)+([Sn]/0.40)+([In]/0.
    Type: Grant
    Filed: May 28, 2013
    Date of Patent: May 9, 2017
    Assignee: Kobe Steel, Ltd.
    Inventors: Shinya Morita, Kenta Hirose, Aya Miki, Toshihiro Kugimiya
  • Patent number: 9624562
    Abstract: Provided is an Al alloy film for display devices, which has excellent heat resistance under high temperatures, low electric resistance (wiring resistance), and excellent corrosion resistance under alkaline environments. The present invention relates to an Al alloy film containing Ge (0.01-2.0 at. %) and a group X element (Ta, Ti, Zr, Hf, W, Cr, Nb, Mo, Ir, Pt, Re, and/or Os), wherein, with regard to precipitates each containing Al, the group X element and Ge generated when a heat treatment at 450 to 600° C. is carried out, the density of some of the precipitates which have equivalent circle diameters of 50 nm or more is controlled.
    Type: Grant
    Filed: February 27, 2012
    Date of Patent: April 18, 2017
    Assignee: Kobe Steel, Ltd.
    Inventors: Hiroyuki Okuno, Toshihiro Kugimiya
  • Publication number: 20170053800
    Abstract: The oxide of the present invention for thin-film transistors is an In—Zn—Sn-based oxide containing In, Zn, and Sn, wherein when the respective contents (atomic %) of metal elements contained in the In—Zn—Sn-based oxide are expressed by [Zn], [Sn], and [In], the In—Zn—Sn-based oxide fulfills the following expressions (2) and (4) when [In]/([In]+[Sn])?0.5; or the following expressions (1), (3), and (4) when [In]/([In]+[Sn])>0.5. [In]/([In]+[Zn]+[Sn])?0.3 - - - (1), [In]/([In]+[Zn]+[Sn])?1.4×{[Zn]/([Zn]+[Sn])}?0.5 - - - (2), [Zn]/([In]+[Zn]+[Sn])?0.83 - - - (3), and 0.1?[In]/([In]+[Zn]+[Sn]) - - - (4). According to the present invention, oxide thin films for thin-film transistors can be obtained, which provide TFTs with excellent switching characteristics, and which have high sputtering rate in the sputtering and properly controlled etching rate in the wet etching.
    Type: Application
    Filed: October 11, 2016
    Publication date: February 23, 2017
    Applicants: KABUSHIKI KAISHA KOBE SEIKO SHO (Kobe Steel, Ltd.), Samsung Display Co., Ltd.
    Inventors: Hiroaki TAO, Aya MIKI, Shinya MORITA, Satoshi YASUNO, Toshihiro KUGIMIYA, Jae Woo PARK, Je Hun LEE, Byung Du AHN, Gun Hee KIM
  • Patent number: 9553201
    Abstract: The inventive concept relates to a thin film transistor and a thin film transistor array panel and, in detail, relates to a thin film transistor including an oxide semiconductor. A thin film transistor according to an exemplary embodiment of the inventive concept includes: a gate electrode; a gate insulating layer positioned on or under the gate electrode; a first semiconductor and a second semiconductor that overlap the gate electrode with the gate insulating layer interposed therebetween, the first semiconductor and the second semiconductor contacting each other; a source electrode connected to the second semiconductor; and a drain electrode connected to the second semiconductor and facing the source electrode, wherein the second semiconductor includes gallium (Ga) that is not included in the first semiconductor, and a content of gallium (Ga) in the second semiconductor is greater than 0 at. % and less than or equal to about 33 at. %.
    Type: Grant
    Filed: February 12, 2014
    Date of Patent: January 24, 2017
    Assignees: Samsung Display Co., Ltd., Kobe Steel, Ltd.
    Inventors: Byung Du Ahn, Ji Hun Lim, Gun Hee Kim, Kyoung Won Lee, Je Hun Lee, Hiroshi Goto, Aya Miki, Shinya Morita, Toshihiro Kugimiya, Yeon Hong Kim, Yeon Gon Mo, Kwang Suk Kim
  • Patent number: 9508856
    Abstract: Provided is a thin film transistor wherein the shape of a protrusion formed on the interface between an oxide semiconductor layer and a protection film is suitably controlled, and stable characteristics are achieved. This thin film transistor is characterized in that: the thin film transistor has an oxide semiconductor layer formed of an oxide containing at least In, Zn and Sn as metal elements, and a protection film directly in contact with the oxide semiconductor layer; and the maximum height of a protrusion formed on the oxide semiconductor layer surface directly in contact with the protection film is less than 5 nm.
    Type: Grant
    Filed: October 15, 2013
    Date of Patent: November 29, 2016
    Assignees: Kobe Steel, Ltd., Samsung Display Co., Ltd.
    Inventors: Hiroaki Tao, Takeaki Maeda, Aya Miki, Toshihiro Kugimiya, Byung Du Ahn, So Young Koo, Gun Hee Kim