Patents by Inventor Toshihiko Itoga

Toshihiko Itoga 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: 6767760
    Abstract: To a polycrystalline silicon layer crystallized by irradiation with laser light, a mixed gas comprised of ozone gas and H2O or N2O gas is fed at a processing temperature of 500° C. or below, or the polycrystalline silicon layer is previously treated with a solution such as ozone water or an aqueous NH3/hydrogen peroxide solution, followed by oxidation treatment with ozone, to form a silicon oxide layer of 4 nm or more thick at the surface of the polycrystalline silicon layer for forming a thin-film transistor having less variations of characteristics on an unannealed glass substrate.
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: July 27, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Kazuhiko Horikoshi, Kiyoshi Ogata, Miwako Nakahara, Takuo Tamura, Yasushi Nakano, Ryoji Oritsuki, Toshihiko Itoga, Takahiro Kamo
  • Patent number: 6716688
    Abstract: An amorphous silicon film is laser irradiated a plural number of times to make the film composed of a plurality of crystal grains while suppressing the formation of protrusions at the boundaries of the adjoining grains to realize a polycrystalline silicon thin film transistor having at least partly therein the clusters of grains, or the aggregates of at least two crystal grains, with preferred orientation in the plane (111), and having high electron mobility of 200 cm2/Vs or above.
    Type: Grant
    Filed: November 18, 2002
    Date of Patent: April 6, 2004
    Assignee: Hitachi, Ltd.
    Inventors: Takuo Tamura, Kiyoshi Ogata, Yoichi Takahara, Kazuhiko Horikoshi, Hironaru Yamaguchi, Makoto Ohkura, Hironobu Abe, Masakazu Saitou, Yoshinobu Kimura, Toshihiko Itoga
  • Patent number: 6657227
    Abstract: An amorphous silicon film is laser irradiated a plural number of times to make the film composed of a plurality of crystal grains while suppressing the formation of protrusions at the boundaries of the adjoining grains to realize a polycrystalline silicon thin film transistor having at least partly therein the clusters of grains, or the aggregates of at least two crystal grains, with preferred orientation in the plane (111), and having high electron mobility of 200 cm2/Vs or above.
    Type: Grant
    Filed: July 19, 2001
    Date of Patent: December 2, 2003
    Assignee: Hitachi, Ltd.
    Inventors: Takuo Tamura, Kiyoshi Ogata, Yoichi Takahara, Kazuhiko Horikoshi, Hironaru Yamaguchi, Makoto Ohkura, Hironobu Abe, Masakazu Saitou, Yoshinobu Kimura, Toshihiko Itoga
  • Publication number: 20030094658
    Abstract: An amorphous silicon film is laser irradiated a plural number of times to make the film composed of a plurality of crystal grains while suppressing the formation of protrusions at the boundaries of the adjoining grains to realize a polycrystalline silicon thin film transistor having at least partly therein the clusters of grains, or the aggregates of at least two crystal grains, with preferred orientation in the plane (111), and having high electron mobility of 200 cm2/Vs or above.
    Type: Application
    Filed: November 18, 2002
    Publication date: May 22, 2003
    Applicant: Hitachi, Ltd.
    Inventors: Takuo Tamura, Kiyoshi Ogata, Yoichi Takahara, Kazuhiko Horikoshi, Hironaru Yamaguchi, Makoto Ohkura, Hironobu Abe, Masakazu Saitou, Yoshinobu Kimura, Toshihiko Itoga
  • Patent number: 6479867
    Abstract: A thin film transistor of high reliability mounted on an insulator substrate, the transistor having a semiconductor thin film, a gate insulation film and a gate electrode in which the concentration profile of impurities in the semiconductor thin film is controlled so as to have a peak in a region other than the center of the depth for the semiconductor thin film to attain a long life for LCD.
    Type: Grant
    Filed: August 29, 2001
    Date of Patent: November 12, 2002
    Assignee: Hitachi, Ltd.
    Inventors: Toshihiko Itoga, Takeo Shiba, Makoto Ohkura, Toshiki Kaneko
  • Publication number: 20020153567
    Abstract: To a polycrystalline silicon layer crystallized by irradiation with laser light, a mixed gas comprised of ozone gas and H2O or N2O gas is fed at a processing temperature of 500° C. or below, or the polycrystalline silicon layer is previously treated with a solution such as ozone water or an aqueous NH3/hydrogen peroxide solution, followed by oxidation treatment with ozone, to form a silicon oxide layer of 4 nm or more thick at the surface of the polycrystalline silicon layer for forming a thin-film transistor having less variations of characteristics on an unannealed glass substrate.
    Type: Application
    Filed: June 11, 2002
    Publication date: October 24, 2002
    Inventors: Kazuhiko Horikoshi, Kiyoshi Ogata, Miwako Nakahara, Takuo Tamura, Yasushi Nakano, Ryoji Oritsuki, Toshihiko Itoga, Takahiro Kamo
  • Publication number: 20020154252
    Abstract: An image display has gate-lines and signal-lines in a matrix shape, and has thin film transistors each having: an island-shaped semiconductor layer having source region, drain region, and channel region sandwiched between them; a first insulation film formed between the semiconductor layer and a gate electrode of the same layer as that of the gate-lines; an interlayer insulation film formed above the semiconductor layer; and a source electrode and a drain electrode existing in the same layer as that of the signal-lines. Each capacitor has: a storage electrode of the same layer as that of the gate-lines; an insulation film formed on the storage electrode and being in contact therewith; and an electrode formed on the insulation film and being in contact therewith and existing in the same layer as that of the signal-lines.
    Type: Application
    Filed: January 17, 2002
    Publication date: October 24, 2002
    Inventors: Yoshiaki Toyota, Toshihiko Itoga, Hajime Akimoto
  • Publication number: 20020113264
    Abstract: To a polycrystalline silicon layer crystallized by irradiation with laser light, a mixed gas comprised of ozone gas and H2O or N2O gas is fed at a processing temperature of 500° C. or below, or the polycrystalline silicon layer is previously treated with a solution such as ozone water or an aqueous NH3/hydrogen peroxide solution, followed by oxidation treatment with ozone, to form a silicon oxide layer of 4 nm or more thick at the surface of the polycrystalline silicon layer for forming a thin-film transistor having less variations of characteristics on an unannealed glass substrate.
    Type: Application
    Filed: November 20, 2001
    Publication date: August 22, 2002
    Inventors: Kazuhiko Horikoshi, Kiyoshi Ogata, Miwako Nakahara, Takuo Tamura, Yasyshi Nakano, Ryoji Oritsuki, Toshihiko Itoga, Takahiro Kamo
  • Publication number: 20020074550
    Abstract: A thin film transistor of high reliability mounted on an insulator substrate, the transistor having a semiconductor thin film, a gate insulation film and a gate electrode in which the concentration profile of impurities in the semiconductor thin film is controlled so as to have a peak in a region other than the center of the depth for the semiconductor thin film to attain a long life for LCD.
    Type: Application
    Filed: August 29, 2001
    Publication date: June 20, 2002
    Applicant: Hitachi, Ltd.
    Inventors: Toshihiko Itoga, Takeo Shiba, Makoto Ohkura, Toshiki Kaneko
  • Publication number: 20020066931
    Abstract: An amorphous silicon film is laser irradiated a plural number of times to make the film composed of a plurality of crystal grains while suppressing the formation of protrusions at the boundaries of the adjoining grains to realize a polycrystalline silicon thin film transistor having at least partly therein the clusters of grains, or the aggregates of at least two crystal grains, with preferred orientation in the plane (111), and having high electron mobility of 200 cm2/Vs or above.
    Type: Application
    Filed: July 19, 2001
    Publication date: June 6, 2002
    Inventors: Takuo Tamura, Kiyoshi Ogata, Yoichi Takahara, Kazuhiko Horikoshi, Hironaru Yamaguchi, Makoto Ohkura, Hironobu Abe, Masakazu Saitou, Yoshinobu Kimura, Toshihiko Itoga